JP3848435B2 - Electric double layer capacitor and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove impurities in an electrical double layer capacitor, by a method wherein specified inorganic oxide fine grains of a high ratio surface area and a low water content are added to an organic electrolyte used to the capacitor and a high- molecular solid electrolyte. SOLUTION: An electrical double layer capacitor is one obtainable by a method wherein a polarized material, such as a carbon material, is dispersed in a high- molecular binder and the material is molded into a capacitor, or is manufactured by a method wherein polarized electrodes 2 impregnated with tan organic electrolyte of a content of less than 1000 ppm are vertically arranged in parallel to the molded material obtained in such a way via an ion conductive layer 3. The layer 3 is formed in such a way that one kind of inorganic oxide fine grains which have a BET ratio surface are of more than 50 m<2> /g comprise primary grains of the largest grain diameter of less than 0.1 &mu;m and have a water content of less than 5000 ppm, are made to contain in the layer 3 in an extent of 1 to 50 wt.%. As a result, impurities in the capacitor can be removed and the stability, safety and reliability of the capacitor are not only increased but the current characteristics of the capacitor can be enhanced.

Description

また、重合性官能基を２つ有する化合物は、例えば、ＭＩ類あるいはＡＩ類と２，２，３，３−テトラフルオロ−１，４−ブタンジオールのようなジオールとを以下の様な反応式で、２：１のモル比で反応させることにより、容易に得られる。
【化１２】

【００４１】
一般式（１）あるいは（２）で表わされる重合性官能基を１つしか有さない化合物を重合してできる高分子は、架橋構造を有しておらず、膜強度不足のため、薄膜にすると短絡する危険が大きく、単独ではもちいない方がよい。従って、一般式（１）あるいは（２）で表わされる重合性官能基を２つ以上有する化合物と共重合し、架橋させた方が好ましい。
高分子固体電解質の薄膜強度を考慮すると、１分子中に含まれる一般式（１）あるいは（２）で表わされる重合性官能基の数は３以上がより好ましい。
また、前記一般式（１）で表わされる重合性官能基を有する化合物の中で、一般式（２）で表わされる重合性官能基を有する化合物から得られる高分子がウレタン基を含んでおり、重合性が良好で、薄膜にしたときの膜強度も大きいので好ましい。
【００４２】
本発明の複合電解質の構成成分として好ましい高分子は、一般式（１）及び／または一般式（２）で表わされる重合性官能基を有する化合物の少なくとも一種を重合し、あるいは該化合物を共重合成分として重合することにより得られる。本発明の複合電解質に用いる高分子は、前記一般式（１）及び／または一般式（２）で表わされる重合性官能基を有する化合物の単独重合体であっても、該カテゴリーに属する２種以上の共重合体であっても、あるいは該カテゴリーに属する化合物の少なくとも一種と他の重合性化合物との共重合体であってもよい。
【００４３】
前記一般式（１）及び／または一般式（２）で表わされる重合性官能基を有する化合物と共重合可能な他の重合性化合物には特に制限はない。
例えば、アクリルアミド、メタクリルアミド、Ｎ，Ｎ−ジメチルアクリルアミド、Ｎ，Ｎ−ジメチルメタクリルアミド、アクリロイルモルホリン、メタクリロイルモルホリン、Ｎ，Ｎ−ジメチルアミノプロピル（メタ）アクリルアミド等の（メタ）アクリルアミド系化合物、スチレン、α−メチルスチレン等のスチレン系化合物、Ｎ−ビニルアセトアミド、Ｎ−ビニルホルムアミド等のＮ−ビニルアミド系化合物、エチルビニルエーテル等のアルキルビニルエーテルを挙げることができる。
【００４４】
重合は、重合性化合物中のアクリロイル基もしくはメタクリロイル基の重合性を利用した一般的な方法を採用することができる。すなわち、これらモノマー単独、あるいはこれらモノマーと他の前記の共重合可能な重合性化合物の混合物に、アゾビスイソブチロニトリル、ベンゾイルパーオキサイド等のラジカル重合触媒、ＣＦ₃ＣＯＯＨ等のプロトン酸、ＢＦ₃、ＡｌＣｌ₃等のルイス酸等のカチオン重合触媒、あるいはブチルリチウム、ナトリウムナフタレン、リチウムアルコキシド等のアニオン重合触媒を用いて、ラジカル重合、カチオン重合あるいはアニオン重合させることができる。また、重合性化合物によっては無酸素状態で、加熱のみでラジカル重合することもできる。
【００４５】
本発明の高分子固体電解質に用いられる高分子はオキシアルキレン構造を含んでいるものが好ましいが、その場合のオキシアルキレン鎖数（すなわち、前記一般式（１）におけるＲ²中、あるいは前記一般式（２）におけるＲ⁵中に含まれるオキシアルキレン基の繰返し数ｎ）は１〜1000の範囲が好ましく、５〜１００の範囲が特に好ましい。
本発明の高分子固体電解質には上述した有機溶媒を添加することが好ましい。高分子固体電解質中の溶媒の含有量が多いほど、電解質塩の解離またはイオンの拡散が容易で、またその場合のイオン伝導度は高くなるが、膜としての機械的強度が低下する。好ましい添加量としては、本発明の高分子固体電解質中の高分子重量の0.5倍から１２倍量以下で、１倍量から８倍量以下が特に好ましい。
【００４６】
［３］電気二重層コンデンサの製造方法
このようにして調製された有機電解液または高分子固体電解質は、上述のように電気二重層コンデンサの分極性電極として、及び／またはその間に設けられるイオン伝導層として用いられる。
分極性電極に用いる場合には、活性炭や黒鉛等の分極性材料を慣用の高分子材料と混合し、フィルム状に成形した後、乾燥、光照射または加熱等により硬化させ、これに上記の無機微粒子を含有させた有機電解液を含浸する。あるいは、上記の［２］で詳述した重合性官能基を有する（メタ）アクリロイル系化合物等の少なくとも一種に、少なくとも一種の無機酸化物微粒子、またはさらに少なくとも一種の電解質塩を添加した上記の組成物に分極性材料及び必要に応じて重合開始剤を混合し、フィルム状に成形した後、乾燥、光照射または加熱等により硬化させる。
【００４７】
イオン伝導層に用いる場合には、慣用のセパレータ材料、例えば、後述の多孔性フィルムに上記の無機微粒子を含有させた有機電解液を含浸する。あるいは、上記の重合性組成物を各種基材上に成膜、塗布後、加熱及び／または活性光線照射により重合し硬化する方法が、均一に成膜でき、膜厚制御が簡便であり、推奨できる。この自立フィルムにさらに上記の無機微粒子を含有させた有機電解液を含浸させてもよい。
【００４８】
上記のいずれにおいても高分子固体電解質は他の多孔性高分子フィルムと複合することにより強度改善等を行なうことも可能である。但し、使用する高分子の種類、フィルム形状、複合割合によってはイオン伝導度の低下や安定性の悪化を招くので、適したものを選ぶ必要がある。使用する多孔性高分子フィルムとしてはポリプロピレン製不織布やポリエチレン製ネットのような網状ポリオレフィンシート等の多孔性ポリオレフィンフィルム、セルガード（商品名）等のポリオレフィン製マイクロポーラスフィルム、ナイロン不織布、ポリエステル性ネット等が挙げられるが、安定性の面でポリオレフィン製多孔性フィルムが好ましい。また、その空孔率は、１０〜９０％程度あればよいが、強度の許す限りできるだけ空孔率の大きいものがよいので、好ましい空孔率の範囲は４０〜９０％の範囲である。
【００４９】
なお、加熱重合する場合の温度は、重合性化合物の種類や開始剤の種類によるが、重合が起こる温度であれば良く、通常は、０℃から２００℃の範囲で行えばよい。活性光線照射により重合させる場合にも、重合性化合物の種類等によるが、例えば、ベンジルメチルケタール、ベンゾフェノン等の活性光線開始剤を使用して、数ｍＷ以上の紫外光または電子線、γ線等を照射して重合させることができる。
このようにして得た分極性電極の間にイオン伝導層を挟み、さらに分極性電極の外表面にリード線を接続した集電体全体を重ね、全体をポリオレフィン樹脂、エポキシ樹脂等の絶縁樹脂で封止することにより電気二重層コンデンサが形成される。
あるいは、ＳＵＳ等の金属、ポリプロピレン、アルミラミネート熱融着樹脂、ポリイミド、エバール、または導電性もしくは絶縁性ガラス等のセラミックス材料等からなる電気二重層コンデンサ構成用構造体あるいは支持体に分極性電極をスペーサを挟んで装入し、その間に電解液または重合性組成物を注入した後、重合性組成物を硬化させてもよい。
【００５０】
また、本発明においては、本発明に従い無機微粉末を含有させた分極性電極の上に高分子電解質膜を直接形成してもよい。この方法によれば両者が密着した電極−高分子固体電解質積層体が得られ、さらにこの高分子固体電解質膜を挟んでもう１枚の分極性電極を貼り合わせるだけで電気二重層コンデンサを製造できる。
本発明の電気二重層コンデンサは比表面積が高く、含水量の低い特定の無機酸化物微粒子が添加された有機電解液及び／または高分子固体電解質を用いているため、コンデンサ特性に悪影響を及ぼす不純物をトラップでき、安定で、信頼性が高く、長寿命の電気二重層コンデンサとすることができる。
【００５１】
さらに添加された無機酸化物微粒子は、電解質イオンとの相互作用が大きく、有機電解液及び／または高分子固体電解質中でのイオンの移動性が改善され、取り出し電流の大きい電気二重層コンデンサとすることができる。
本発明では、（メタ）アクリル基及び／またはウレタン（メタ）アクリル基を有する重合性化合物が硬化特性に優れていることを利用し、これら化合物とアルミナ微粒子と電解質塩、または／さらに有機溶媒を混合した重合性組成物を電極上に配置後、加熱及び／または活性光線照射により硬化させることにより、電気二重層コンデンサに最適な高分子固体電解質／分極性電極積層体を容易に製造できる。このため、さらに該高分子固体電解質／分極性電極積層体を用いることにより、安定で信頼性が高く、長寿命の電気二重層コンデンサを容易に得ることができる。また、電極面積を広くし、電極間隔を小さくして容量の改善を図ることも容易である。
【００５２】
【実施例】
以下に本発明について代表的な例を示し具体的に説明する。なお、これらは説明のための単なる例示であって、本発明はこれらに何等制限されるものではない。なお、以下の実施例、参考例、比較例において含水量はカールフィッシャー法により測定した。
【００５３】
実施例１：重合性化合物（化合物３）の合成
下記の反応式にしたがい、グリセリンエステルである化合物１とイソシアナート基を含有するメタクリレートである化合物２とを反応させ熱重合性化合物３を得た。
【化１３】

具体的には、化合物１（ＫＯＨ価 34.0ｍｇ／ｇ、ｐ／ｑ＝７／３）50.0ｇ及び4.6ｇの化合物２を窒素雰囲気中でよく精製したＴＨＦ100ｍｌに溶解した後、0.44ｇのジブチルチンジラウレートを添加した。その後、２５℃で約１５時間反応させることにより、無色の粘稠液体を得た。その¹ Ｈ-ＮＭＲ、ＩＲ及び元素分析の結果から、化合物１と化合物２は１対３で反応し、さらに、化合物２のイソシアナート基が消失し、ウレタン結合が生成しており、化合物３が生成していることがわかった。
【００５４】
参考例１：固体電解質フィルム（ａ）の調製
化合物３（1.0ｇ）の、エチレンカーボネート（ＥＣ）（1.8ｇ）、プロピレンカーボネート（ＰＣ）（4.2ｇ）、テトラエチルアンモニウムテトラフルオロボレート（ＴＥＡＢ）（0.8ｇ）、及び２，４，６−トリメチルベンゾイルジフェニルホスフィンオキサイド（商品名ルシリンＴＰＯ、ＢＡＳＦ社製）（0.005ｇ）をアルゴン雰囲気中でよく混合し、光重合性組成物を得た。この組成物の含水量は１００ｐｐｍであった。
この光重合性組成物をアルゴン雰囲気下、ＰＥＴフィルム上に塗布後、ケミカル蛍光ランプ（三共電気（株）社製 FL20S.BL）を１０分間照射したところ、ＥＣ／ＰＣ系電解液を含浸した化合物３重合体フィルム（「固体電解質フィルム （ａ）」）が約３０μｍの自立フィルムとして得られた。このフィルムの２５℃、−２０℃でのイオン伝導度をインピーダンス法にて測定したところ、それぞれ、7.3×10^-3、1.6×10^-3Ｓ／ｃｍであった。
【００５５】
実施例２：アルミナ含有固体電解質フィルム（Ａ）の調製
乾燥空気雰囲気中、1000℃で２時間熱処理した昭和電工（株）製高純度γ−アルミナ（商品名：UA5805、結晶粒子径：0.03μｍ、平均二次粒子径：1.8μｍ、ＢＥＴ比表面積：８０ｍ²／ｇ）（0.33ｇ）、化合物３（1.0ｇ）、ＥＣ（1.8ｇ）、ＰＣ（4.2ｇ）、ＴＥＡＢ（1.2ｇ）、及びルシリンＴＰＯ（ＢＡＳＦ社製）（0.005ｇ）をアルゴン雰囲気中でよく混合し、光重合性組成物を得た。この組成物の含水量は３０ｐｐｍであった。
この光重合性組成物をアルゴン雰囲気下、ＰＥＴフィルム上に塗布後、ケミカル蛍光ランプ（三共電気（株）社製 FL20S.BL）を１０分間照射したところ、ＥＣ／ＰＣ電解液を含浸した化合物３重合体／UA5805複合フィルム（「固体電解質フィルム（Ａ）」）が約３０μｍの自立フィルムとして得られた。このフィルムの２５℃、−２０℃でのイオン伝導度をインピーダンス法にて測定したところ、それぞれ、7.8×10^-3、1.8×10^-3Ｓ／ｃｍであった。
【００５６】
参考例２：固体電解質フィルム（ｂ）の調製
乾燥空気雰囲気中、８０℃で２４時間熱処理した昭和電工（株）製高純度γ−アルミナ（商品名：UA5805、結晶粒子径：0.03μｍ、平均二次粒子径：1.8μｍ、ＢＥＴ比表面積：８０ｍ²/ｇ）（0.33ｇ）、化合物３（1.0ｇ）の、ＥＣ（1.8ｇ）、ＰＣ（4.2ｇ）、ＴＥＡＢ（1.2ｇ）、及びルシリンＴＰＯ（ＢＡＳＦ社製）（0.005ｇ）をアルゴン雰囲気中でよく混合し、光重合性組成物を得た。この組成物の含水量は1100ｐｐｍであった。
この光重合性組成物をアルゴン雰囲気下、ＰＥＴフィルム上に塗布後、ケミカル蛍光ランプ（三共電気（株）社製 FL20S.BL）を１０分間照射したところ、ＥＣ／ＰＣ電解液を含浸した化合物３重合体／低温処理UA5805複合フィルム（「固体電解質フィルム（ｂ）」が約３０μｍの自立フィルムとして得られた。このフィルムの２５℃、−２０℃でのイオン伝導度をインピーダンス法にて測定したところ、それぞれ、7.0×１０^-3、1.4×１０^-3Ｓ/ｃｍであった。
【００５７】
実施例３：アルミナ含有固体電解質フィルム（Ｂ）の調製
アルミナ系微粒子としてUA5805の代りに1000℃熱処理したアルミニウムオキサイドＣ（商品名，日本アエロジル（株）製，結晶粒子径：0.013μｍ，平均二次粒子径：0.11μｍ（ＳＥＭ観察）、ＢＥＴ比表面積：１００ｍ²／ｇ）（0.33ｇ）を添加した以外は実施例２と同様にして、光重合性組成物を得た。この組成物の含水量は３５ｐｐｍであった。
この光重合性組成物を実施例２と同様に塗布、光照射することにより、ＥＣ／ＰＣ電解液を含浸した化合物３重合体／アルミニウムオキサイドＣ複合フィルム（「固体電解質フィルム（Ｂ）」）が約３０μｍの自立フィルムとして得られた。このフィルムの２５℃、−２０℃でのイオン伝導度をインピーダンス法にて測定したところ、それぞれ、8.3×10^-3、2.3×10^-3Ｓ／ｃｍであった。
【００５８】
参考例３：固体電解質フィルム（ｃ）の調製
開始剤としてルシリンＴＰＯ（0.005ｇ）の代りに、ベンゾイルパーオキサイド（ＢＰＯ）（0.04ｇ）を添加した以外は参考例１と同様にして、熱重合性組成物を得た。この組成物の含水量は３５ｐｐｍであった。
この熱重合性組成物をアルゴン雰囲気下、ＰＥＴフィルム上に塗布後、ＰＰフィルムを被覆して、ホットプレート上で８０℃、１時間加熱したところ、ＥＣ／ＰＣ電解液を含浸した化合物３重合体フィルム（「固体電解質フィルム（ｃ）」）が約３０μｍの自立フィルムとして得られた。このフィルムの２５℃、−２０℃でのイオン伝導度をインピーダンス法にて測定したところ、それぞれ、7.8×10^-3、1.5×10^-3Ｓ／ｃｍであった。
【００５９】
参考例４：固体電解質フィルム（ｄ）の調製
乾燥空気雰囲気中、1000℃で２時間熱処理した昭和電工（株）製α−アルミナ（商品名：A-420、結晶粒子径：0.4μｍ、平均二次粒子径：3.2μｍ、ＢＥＴ比表面積：2.2ｍ²/ｇ）（0.33ｇ）、化合物３（1.0ｇ）の、ＥＣ（1.8ｇ）、ＰＣ（4.2ｇ）、ＴＥＡＢ（1.2ｇ）、及びルシリンＴＰＯ（ＢＡＳＦ社製）（0.005ｇ）をアルゴン雰囲気中でよく混合し、光重合性組成物を得た。この組成物の含水量は４０ｐｐｍであった。
この光重合性組成物をアルゴン雰囲気下、ＰＥＴフィルム上に塗布後、ケミカル蛍光ランプ（三共電気（株）社製 FL20S.BL）を１０分間照射したところ、ＥＣ／ＰＣ電解液を含浸した化合物３重合体／低温処理A-420複合フィルム（「固体電解質フィルム（ｄ）」が約３０μｍの自立フィルムとして得られた。このフィルムの２５℃、−２０℃でのイオン伝導度をインピーダンス法にて測定したところ、それぞれ、6.0×１０^-3、1.0×１０^-3Ｓ/ｃｍであった。
【００６０】
実施例４：アルミナ含有固体電解質フィルム（Ｃ）の調製
電解質塩としてＴＥＡＢの代りに、テトラエチルホスフォニウムテトラフルオロボレート（ＴＥＰＢ）を同量用いた以外は、実施例３と同様にして、光重合性組成物を得た。この組成物の含水量は３０ｐｐｍであった。
この光重合性組成物を実施例３と同様に塗布、光照射することにより、電解液を含浸した化合物３重合体／アルミニウムオキサイドＣ複合フィルム（「固体電解質フィルム（Ｃ）」）を約３０μｍの自立フィルムとして得た。この固体電解質の２５℃、−２０℃でのイオン伝導度をインピーダンス法にて測定したところ、6.30×10^-3、1.0×10^-3Ｓ／ｃｍであった。
【００６１】
実施例５：重合性化合物（化合物５）の合成
【化１４】

化合物４（２，２，３，３，４，４，４−ヘプタフルオロ−１−ブタノール、アルドリッチ製）２０ｇ、化合物６（15.5ｇ）を窒素雰囲気中でよく精製したＴＨＦ１００ｍｌに混合した後、ジブチルチンジラウレート（0.66ｇ）を添加する。その後、２５℃で約１５時間反応させることにより、無色の粘稠液体として化合物５を得た。その¹ Ｈ-ＮＭＲ、ＩＲ及び元素分析の結果から、化合物４と化合物６は１対１で反応し、さらに、化合物６のイソシアナート基が消失し、ウレタン結合が生成してしていることがわかった。
【００６２】
実施例６：アルミナ含有固体電解質フィルム（Ｄ）の調製
化合物５（0.5ｇ）、化合物３（0.3ｇ）、1000℃熱処理したアルミニウムオキサイドＣ（0.22ｇ）、ＥＣ（1.8ｇ）、ＰＣ（4.2ｇ）、ＴＥＡＢ（1.2ｇ）及びルシリンＴＰＯ（ＢＡＳＦ社製）（0.005ｇ）をアルゴン雰囲気中でよく混合し、光重合性組成物を得た。この組成物の含水量は２０ｐｐｍであった。
この光重合性組成物をアルゴン雰囲気下、ＰＥＴフィルム上に塗布後、ケミカル蛍光ランプ（三共電気（株）社製 FL20S.BL）を１０分照射したところ、ＥＣ／ＰＣ電解液を含浸した化合物５＋化合物３共重合体／UA5805複合フィルム（ 「固体電解質フィルム（Ｄ）」）が約３０μｍの自立フィルムとして得られた。このフィルムの２５℃、−２０℃でのイオン伝導度をインピーダンス法にて測定したところ、それぞれ、6.0×10^-3、1.0×10^-3Ｓ／ｃｍであった。
【００６３】
実施例７：シリカ含有固体電解質フィルム（Ｅ）の調製
無機酸化物微粒子としてUA5805の代りに1000℃熱処理した日本アエロジル製シリカ微粒子（アエロジル２００、結晶粒子径：0.012μｍ、平均二次粒子径：約0.1μｍ（ＳＥＭ観察）、ＢＥＴ比表面積：１８０ｍ²／ｇ）（0.33ｇ）を添加した以外は実施例２と同様にして、光重合性組成物を得た。この組成物の含水量は３０ｐｐｍであった。
この光重合性組成物を実施例２と同様に塗布、光照射することにより、ＥＣ／ＰＣ電解液を含浸した化合物３重合体／アルミニウムオキサイドＣ複合フィルム（「固体電解質フィルム（Ｅ）」）が約３０μｍの自立フィルムとして得られた。このフィルムの２５℃、−２０℃でのイオン伝導度をインピーダンス法にて測定したところ、それぞれ、6.6×10^-3、1.6×10^-3Ｓ／ｃｍであった。
【００６４】
実施例８：アルミナ含有有機電解液（Ａ）の調製
1000℃熱処理したアルミニウムオキサイドＣ（0.33ｇ）、ＰＣ（6.0ｇ）、ＴＥＡＢ（0.80ｇ）をアルゴン雰囲気中、室温でよく混合し、電解液（「有機電解液（Ａ）」）を調製した。この電解液の含水量は２０ｐｐｍであった。この電解液の２５℃、−２０℃でのイオン伝導度をインピーダンス法にて測定したところ、それぞれ、10.0×10^-3、3.0×10^-3Ｓ／ｃｍであった。また、回転粘度計での粘度は１５０ｃｐｓ（３８０ｓ^-1）であった。
【００６５】
実施例９：アルミナ含有有機電解液（Ｂ）の調製
1000℃熱処理アルミニウムオキサイドＣ（0.33ｇ）、ＰＣ3.0ｇ、γ−ブチロラクトン（γＢＬ）（3.0ｇ）、ＴＥＡＢ（0.80ｇ）をアルゴン雰囲気中、室温でよく混合し、電解液（「有機電解液（Ｂ）」）を調製した。この電解液の含水量（カールフィッシャー法）は７０ｐｐｍであった。この電解液の２５℃、−２０℃でのイオン伝導度をインピーダンス法にて測定したところ、それぞれ、12.0×10^-3、3.0×10^-3Ｓ／ｃｍであった。また、回転粘度計での粘度は１２０ｃｐｓ（３８０ｓ^-1）であった。
【００６６】
以上の実施例１〜９、参考例１〜３において製造した固体電解質フィルム（Ａ〜Ｅ）、（ａ〜ｃ）及び有機電解液（Ａ及びＢ）の成分を表１にまとめて示す。
【００６７】
【表１】

【００６８】
実施例１０：活性炭電極（ａ）の製造
椰子がら活性炭とポリフッ化ビニリデンの重量比9.0:1.0の混合物に過剰のＮ−メチルピロリドン溶液を加え、ゲル状組成物を得た。この組成物をステンレス箔上に１５ｍｍφの大きさで約１５０μｍの厚さに塗布した。約１００℃で１０時間真空乾燥し、活性炭電極(24.8ｍｇ)を得た。
【００６９】
実施例１１：コイン型電気二重層コンデンサの製造
アルゴン雰囲気グローブボックス内で、実施例１０で製造した活性炭電極（ａ）（24.8ｍｇ）に実施例９で調製した有機電解液（Ｂ）［アルミニウムオキサイドＣ添加電解液（ＴＥＡＢ／ＰＣ＋γＢＬ）］を含浸させた電極を２個用意した。次に、ポリオレフィンマイクロポーラスフィルム（１６ｍｍφ、開孔率約６５％、厚み２５μｍ）に前記アルミニウムオキサイドＣ添加電解液（実施例１０）を含浸したものを一方の電極に貼り合わせ、さらにもう一枚の電極をはり合わせ、2016コイン型缶（直径２０ｍｍ，厚み1.6ｍｍ）に封印し、コイン型電気二重層コンデンサを得た。
このコンデンサを、作動電圧０〜2.5Ｖ、電流0.35ｍＡ、3.5ｍＡで充放電を行なったところ、最大容量は各々８５０ｍＦ、７７０ｍＦであった。また、3.5ｍＡで充放電を１００回繰り返してもほとんど容量に変化はなかった。
【００７０】
実施例１２：コイン型電気二重層コンデンサの製造
電解液として実施例８で調製した有機電解液（Ａ）［アルミニウムオキサイドＣ添加電解液（ＴＥＡＢ／ＰＣ）］を用いた以外は実施例１１と同様にしてコイン型（2016）電気二重層コンデンサを得た。
このコンデンサを、作動電圧０〜2.5Ｖ、電流0.35ｍＡ、3.5ｍＡで充放電を行なったところ、最大容量は８３０ｍＦ、６６０ｍＦであった。また、3.5ｍＡで充放電を１００回繰り返してもほとんど容量に変化はなかった。
【００７１】
実施例１３：活性炭電極（ｂ）の製造
椰子がら活性炭とポリフッ化ビニリデンの重量比9.0:1.0の混合物に過剰のＮ−メチルピロリドン溶液を加え、ゲル状組成物を得た。この組成物をステンレス箔上に１０ｍｍ×１０ｍｍの大きさで約１５０μｍの厚さに塗布した。約１００℃で１０時間真空乾燥し、活性炭電極(14.0ｍｇ)を得た。
【００７２】
実施例１４：薄型電気二重層コンデンサの製造
アルゴン雰囲気グローブボックス内で、実施例１３で製造した活性炭電極（ｂ）（14.0ｍｇ）１０ｍｍ×１０ｍｍに、電解液（１Ｍ ＴＥＡＢ／ＰＣ＋ＥＣ（３：１））を含浸させた電極を二個用意した。次に、実施例３で製造した固体電解質フィルムＢ［化合物３重合体／アルミニウムオキサイドＣ複合フィルム］（１２ｍｍ×１２ｍｍ）を一方の電極に貼り合わせ、さらにもう一枚の電極をはり合わせ、コンデンサ端部をエポキシ樹脂で封止することにより、図１に示す構成の薄型電気二重層コンデンサを製造した。
このコンデンサを、作動電圧０〜2.5Ｖ、電流0.2ｍＡ、2.0ｍＡで充放電を行なったところ、最大容量は４７０ｍＦ、４２３ｍＦであった。また、2.0ｍＡで充放電を１００回繰り返してもほとんど容量に変化はなかった。
【００７３】
実施例１５：薄型電気二重層コンデンサの製造
高分子固体電解質フィルムとして、実施例４で製造した固体電解質フィルム （Ｃ）［ＴＥＰＢ系化合物３重合体／アルミニウムオキサイドＣ複合フィルム］（１２ｍｍ×１２ｍｍ）、電解液として１Ｍ ＴＥＰＢ／ＰＣ＋ＥＣ（３：１）を用いた以外は実施例１４と同様にして薄型電気二重層コンデンサを製造した。このコンデンサを、作動電圧０〜2.5Ｖ、電流0.2ｍＡ、2.0ｍＡで充放電を行なったところ、最大容量は４５０ｍＦ、３６０ｍＦであった。また、2.0ｍＡで充放電を１００回繰り返してもほとんど容量に変化はなかった。
【００７４】
実施例１６：薄型電気二重層コンデンサの製造
高分子固体電解質フィルムとして、実施例６で製造した固体電解質フィルム （Ｄ）［化合物５＋化合物３共重合体／アルミニウムオキサイドＣ複合フィルム］（１２ｍｍ×１２ｍｍ）を用いた以外は実施例１４と同様にして薄型電気二重層コンデンサを製造した。
このコンデンサを、作動電圧０〜2.5Ｖ、電流0.2ｍＡ、2.0ｍＡで充放電を行なったところ、最大容量は４５０ｍＦ、４１０ｍＦであった。また、2.0ｍＡで充放電を１００回繰り返してもほとんど容量に変化はなかった。
【００７５】
実施例１７：薄型電気二重層コンデンサの製造
高分子固体電解質フィルムとして、実施例６で製造した固体電解質フィルム （Ｄ）［化合物５＋化合物３共重合体／アルミニウムオキサイドＣ複合フィルム］（１２ｍｍ×１２ｍｍ）、電解液として有機電解液Ｂ［アルミニウムオキサイドＣ添加ＴＥＡＢ／ＰＣ＋γＢＬ（実施例９）］を用いた以外は実施例１４と同様にして薄型電気二重層コンデンサを製造した。
このコンデンサを、作動電圧０〜2.5Ｖ、電流0.2ｍＡ、2.0ｍＡで充放電を行なったところ、最大容量は４８０ｍＦ、４３０ｍＦであった。また、2.0ｍＡで充放電を１００回繰り返してもほとんど容量に変化はなかった。
【００７６】
比較例１：薄型電気二重層コンデンサの製造
高分子固体電解質フィルムとして、参考例１で製造した固体電解質フィルム （ａ）［化合物３重合体フィルム］（１２ｍｍ×１２ｍｍ）を用いた以外は実施例１４と同様にして薄型電気二重層コンデンサを製造した。
このコンデンサを、作動電圧０〜2.5Ｖ、電流0.2ｍＡ、2.0ｍＡで充放電を行なったところ、最大容量は４５０ｍＦ、３５０ｍＦであった。また、2.0ｍＡで充放電を１００回繰り返すと容量は１０％低下した。
【００７７】
比較例２：薄型電気二重層コンデンサの製造
高分子固体電解質フィルムとして、参考例２で製造した固体電解質フィルム （ｂ）［化合物３重合体／低温熱処理UA5805複合フィルム］（１２ｍｍ×１２ｍｍ）を用いた以外は実施例１４と同様にして薄型電気二重層コンデンサを製造した。
このコンデンサを、作動電圧０〜2.5Ｖ、電流0.2ｍＡ、2.0ｍＡで充放電を行なったところ、最大容量は４５０ｍＦ、４００ｍＦであった。また、2.0ｍＡで充放電を１００回繰り返すと容量は３０％低下した 。
【００７８】
実施例１８：薄型電気二重層コンデンサの製造
高分子固体電解質フィルムとして、実施例７で製造した固体電解質フィルム （Ｅ）［化合物３重合体／シリカ微粒子複合フィルム］（１２ｍｍ×１２ｍｍ）を用いた以外は実施例１４と同様にして薄型電気二重層コンデンサを製造した。このコンデンサを、作動電圧０〜2.5Ｖ、電流0.2ｍＡ、2.0ｍＡで充放電を行なったところ、最大容量は４４０ｍＦ、３６０ｍＦであった。また、2.0ｍＡで充放電を１００回繰り返してもほとんど容量に変化はなかった。
【００７９】
実施例１９：全固体薄型電気二重層コンデンサの製造
アルゴン雰囲気グローブボックス内で、実施例１３で製造した活性炭電極（ｂ）（１４ｍｇ）１０ｍｍ×１０ｍｍに、参考例３で調製した熱重合性組成物（化合物３／ＴＥＡＢ ／ＰＣ＋ＥＣ）を含浸させた電極を二個用意した。次に、実施例３で製造した固体電解質フィルムＢ［化合物３重合体／アルミニウムオキサイドＣ複合フィルム］（１２ｍｍ×１２ｍｍ）を一方の電極に貼り合わせ、さらにもう一枚の電極をはり合わせ、コンデンサ端部をエポキシ樹脂で封止し、熱重合性組成物を８０℃で１時間加熱重合させることにより、図１に示す構成の全固体薄型電気二重層コンデンサを製造した。
このコンデンサを、作動電圧０〜2.5Ｖ、電流0.2ｍＡ、2.0ｍＡで充放電を行なったところ、最大容量は４００ｍＦ、２００ｍＦであった。また、0.2ｍＡで充放電を１００回繰り返してもほとんど容量に変化はなかった。
【００８０】
実施例２０：薄型電気二重層コンデンサの製造
アルゴン雰囲気グローブボックス内で、実施例１３で製造した活性炭電極（ｂ）（１４ｍｇ）１０ｍｍ×１０ｍｍに、電解液（１Ｍ ＴＥＡＢ／ＰＣ＋ＥＣ（３：１））を含浸させた電極を二個用意した。次に、実施例３で調製した化合物３重合体／アルミニウムオキサイドＣ系光重合性組成物を一方の電極上に塗布後、ケミカル蛍光ランプを１０分間照射し、活性炭電極上に約３０μｍ化合物３重合体／アルミニウムオキサイドＣ複合フィルムを形成させた。次いでこのフィルム上にさらにもう一枚の電極をはり合わせ、コンデンサ端部をエポキシ樹脂で封止することにより、図１に構成を示すような薄型電気二重層コンデンサを製造した。
このコンデンサを、作動電圧０〜2.5Ｖ、電流0.2ｍＡ、2.0ｍＡで充放電を行なったところ、最大容量は４８０ｍＦ、４４６ｍＦであった。また、2.0ｍＡで充放電を１００回繰り返してもほとんど容量に変化はなかった。
【００８１】
以上の実施例１４〜２０、比較例１〜２において製造した薄型電気二重層コンデンサの構成要素及び繰り返し使用結果の概要を表２にまとめて示す。
【００８２】
【表２】

【００８３】
【発明の効果】
本発明の電気二重層コンデンサは高比表面積で低含水量の特定の無機酸化物微粒子が添加された有機電解液及び／または高分子固体電解質を用いているため、安定で、信頼性が高く、長寿命で、取り出し電流の大きい電気二重層コンデンサとすることができる。
本発明によれば、（メタ）アクリル基及び／またはウレタン（メタ）アクリル基を有する硬化特性に優れた重合性化合物を加熱及び／または活性光線照射により硬化させることにより、電気二重層コンデンサに最適な高分子固体電解質／分極性電極積層体を容易に製造できる。さらに該高分子固体電解質／分極性電極積層体を用いることにより、安定で、信頼性が高く、長寿命の電気二重層コンデンサを容易に得ることができる。
【図面の簡単な説明】
【図１】 本発明の電気二重層コンデンサの一例として示す、薄型電気二重層コンデンサの実施例の概略断面図である。
【符号の説明】
１ 集電体
２ 分極性電極
３ イオン伝導層
４ 絶縁性樹脂封止剤
５ リード線[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electric double layer capacitor and a method for manufacturing the same. More specifically, the present invention relates to an electric double layer capacitor using an organic electrolyte and / or a solid polymer electrolyte to which inorganic oxide fine particles are added, and a method for producing the same.
[0002]
[Prior art]
In recent years, an electric double layer capacitor in which an ion conductive solution is placed between a carbon material having a large specific surface area such as activated carbon or carbon black as a polarizable electrode has been widely used for a memory backup power source or the like. For example, “March 1988 (No. 18)” of “173rd Electrochemical Society Meeting Atlanta Georgia” describes an electric double layer capacitor using an aqueous sulfuric acid solution.
Further, “Functional Materials”, February 1989, page 33, a capacitor using a carbon-based polarizable electrode and an organic electrolyte is reported. Although organic electrolytes have lower ionic conductivity than sulfuric acid aqueous solution, they are attracting attention because of their high withstand voltage and large working voltage and capacity of electric double layer capacitors. Various electrolytes and organic solvents are actively studied. Has been. As electrolytes, nitrogen-based cation salts such as quaternary ammonium salts and pyridinium salts and quaternary phosphonium salts are frequently used because of their high solubility and dissociation in organic solvents and a wide electrochemical stability range. Moreover, as an organic solvent, what has a high dielectric constant, a wide electrochemical stability range, and a high boiling point is desired, such as propylene carbonate (PC), butylene carbonate (BC), and γ-butyrolactone (γBL). Cyclic carbonates or lactones are used.
[0003]
However, in the current electric double layer capacitor using the electrolyte solution, liquid leakage to the outside of the capacitor, liquid dripping, etc. are likely to occur during abnormal use such as long-term use or when a high voltage is applied. There are problems with long-term stability and reliability.
In addition, the current electric double layer capacitor using an organic electrolytic solution has a problem that deterioration is accelerated due to a small amount of impurities such as moisture, acid, base and the like mixed from the inside and / or outside of the system. Therefore, the said company pays a lot of effort for the prevention of mixing of impurities during manufacture of electrolyte solution, the storage method after preparation, and the like.
[0004]
Japanese Patent Application Laid-Open No. 3-98263 discloses a problem of the electrolyte by adding a large amount of powdery inert and non-conductive solid such as silica, alumina, titania or the like to the organic electrolyte to eliminate fluidity. Attempts have also been made to resolve. In March 1997, the Electrochemical Society Spring Meeting (Kanagawa University) 1A21 includes LiClO._FourStudies have been made to eliminate the same fluidity by adding a large amount of α-alumina to the organic electrolyte solution. However, even if the fluidity is lost by these methods, the electrolyte itself is not self-supporting and flows with a certain amount of pressure, so that it is not practical. In addition, since a large amount of powder is added to eliminate fluidity, there is a problem that ion conductivity is lowered. Moreover, since the heat treatment of the powder is insufficient, the interaction with the electrolyte ions is small and the effect of improving the ion mobility is small. Moreover, there is also a problem that the impurity adsorption capacity is small, and conversely, OH groups and moisture on the powder surface adversely affect the electrochemical device.
[0005]
On the other hand, a product using a solid electrolyte does not have the same problems as the electrolyte solution such as liquid leakage and liquid leakage, can be easily reduced in thickness, and can be easily sealed. Furthermore, the solid electrolyte is excellent in heat resistance and is advantageous in the production process of the electric double layer capacitor.
However, the solid electrolytes that have been studied so far have a problem that the extraction current is small because of low ionic conductivity.
[0006]
Recently, so-called polymer solid electrolytes in which a polyethylene oxide polymer and an alkali metal salt are combined are attracting attention. As an example of these polymer solid electrolytes, “British Polymer Journal (Br. Polym. J.)” vol. 319, page 137 (1975) shows a complex of polyethylene oxide and inorganic alkali metal salt. It is described that it exhibits conductivity. In addition, it has been reported that comb polymers in which oligooxyethylene is introduced into the side chain enhance the thermal mobility of the oxyethylene chain responsible for ionic conductivity and improve the ionic conductivity. For example, in “J. Phys. Chem.” Vol. 89, 987 (1984), an alkali metal salt is added to the side chain of polymethacrylic acid to which oligooxyethylene is added. An example in which is combined is described. Furthermore, in “J. Am. Chem. Soc.”, Vol. 106, p. 6854 (1984), an alkali metal salt is added to polyphosphazene having an oligooxyethylene side chain. A composite example is described. These are said to be capable of expressing ionic conduction by the thermal motion of the polymer chain by the polymer itself forming a complex with the Li salt that is the electrolyte. Therefore, a hole for passing an electrolytic solution like a current separator is basically unnecessary. However, practically satisfactory film strength and ionic conductivity have not been obtained.
[0007]
That is, the ionic conductivity of a polymer solid electrolyte that is generally studied is 10 at room temperature.^-Four-10^-FiveAlthough improved to about S / cm, the level is still two orders of magnitude lower than that of the liquid ion conductive material. In addition, when the temperature is lower than 0 ° C., the ionic conductivity is extremely lowered. Further, when these solid electrolytes are made into a thin film and incorporated in a battery, processing techniques such as compositing with electrodes and ensuring contact are difficult, and there are problems in the manufacturing method.
[0008]
Thermoplastic polymers such as polyacrylonitrile and polyvinylidene fluoride gel as described in “J. Appl. Electrochem” No. 5, pp. 63-69 (1975) Alternatively, it has been reported that a so-called polymer gel electrolyte obtained by adding a solvent and an electrolyte to a crosslinked polymer has high ionic conductivity. Japanese Patent Publication No. 58-36828 reports that a similar polymer gel electrolyte obtained by adding a solvent and an electrolyte to polymethacrylic acid alkyl ester has high ionic conductivity. However, although these polymer gel electrolytes have high ionic conductivity, they impart fluidity, so they cannot be handled as perfect solids, are inferior in film strength and film formability, and cause short circuits when applied to batteries. In addition, it causes a sealing problem as in the case of the liquid ion conductive material.
[0009]
In US Pat. No. 4,435,401, a polymer solid electrolyte comprising a cross-linked polymer containing a heteroatom and an ionizable salt reduces the crystallinity of the polymer, lowers the glass transition point, and improves the ionic conductivity. It has been reported. However, its ionic conductivity is 10 at room temperature.^-FiveIt is about S / cm, which is still insufficient.
[0010]
Further, US Pat. No. 4,792,504 proposes a solid polymer electrolyte in which a polyoxyethylene cross-linked network is impregnated with an electrolytic solution comprising a metal salt and an aprotic solvent. These indicate that the oxyethylene chain can be impregnated with not only the Li salt but also an aprotic solvent, and can provide a uniform polymer solid electrolyte without pores impregnated with an electrolytic solution that can be used as a separator for a Li battery. Show. However, even in this system, the ionic conductivity is 10^-FourS / cm was still insufficient. Further, since the solvent is added, the film strength is lowered, and there arises a problem that it is difficult to handle at the time of production or when used for a battery or the like.
[0011]
Japanese Patent Publication No. 3-73081 and U.S. Pat. No. 4,908,283 disclose a polymer by irradiating a composition comprising acryloyl-modified polyalkylene oxide / electrolyte salt / organic solvent such as polyethylene glycol diacrylate with an actinic ray such as ultraviolet rays. A method of forming a solid electrolyte has been disclosed and attempts have been made to shorten the polymerization time.
Also, in US Pat. No. 4,830,939 and JP-A-5-109310, a composition comprising a crosslinkable polyethylenically unsaturated compound / electrolyte salt / active light inert solvent is irradiated with radiation such as ultraviolet rays and electron beams. Discloses a similar method for forming a solid polymer electrolyte containing an electrolytic solution. In these systems, although the ionic conductivity is improved because the amount of the electrolytic solution in the polymer solid electrolyte is increased, it is still insufficient and the film strength tends to deteriorate.
[0012]
In order to solve these problems, the present inventors have prepared an ion conductive polymer using a polymer and a composite comprising an electrolyte obtained from a (meth) acrylate prepolymer containing an oxyalkylene group having a urethane bond. A solid electrolyte (Japanese Patent Laid-Open No. 6-187822) has been proposed. The ionic conductivity of this polymer solid electrolyte is 10 when no solvent is added.^-FourAlthough it is at a high level at about S / cm (room temperature), it can be increased by adding a solvent even at room temperature or lower temperature.^-3S / cm or more, the film quality was good, and the film was improved to the extent that it could be obtained as a self-supporting film. In addition, this prepolymer has a good polymerizability, and when applied to a battery, it has a processing advantage that it can be polymerized and solidified after being incorporated in the battery in a prepolymer state. However, these systems also have a problem that the film strength is insufficient to be used as a separator for a battery or the like and it is difficult to handle industrially. In addition, there is also a problem that a polymer, particularly an oxyalkylene moiety is easily deteriorated by a trace amount of impurities in the battery system such as moisture, electrolyte salt decomposition products, electrode material impurities, etc., and the battery life is easily affected.
[0013]
“Solid State Ionics”, 1982, No. 7, page 75, includes LiClO, a polymer solid electrolyte._Four/ It has been reported that by further combining alumina particles with a polyethylene oxide composite, the strength of the polymer solid electrolyte can be improved without lowering the ionic conductivity. JP-A-6-140052 has proposed a solid electrolyte obtained by impregnating a polyalkylene oxide / isocyanate cross-linked body / inorganic oxide composite with a non-aqueous electrolyte. The strength is improved. However, these composite polymer solid electrolytes have insufficient properties of the polymer itself, and problems still remain in practical use in terms of ionic conductivity, processability, and stability.
[0014]
[Problems to be solved by the invention]
The present invention is less affected by impurities and deteriorated with time, is easy to handle, is stable, has high ionic conductivity, and is excellent in safety and reliability. The object is to obtain a large, high-performance electric double layer capacitor with a high working voltage and a long service life.
[0015]
[Means for Solving the Problems]
As a result of intensive studies in view of the above problems, the present inventors have added specific inorganic oxide fine particles having a high specific surface area and a low water content to the organic electrolyte and / or polymer solid electrolyte used in the electric double layer capacitor. It has been found that impurities in the capacitor can be removed, and not only stability, safety and reliability are increased, but also current characteristics are improved. In the present specification, the expression “oxyalkylene” includes oligooxyalkylene and polyoxyalkylene containing at least one oxyalkylene group.
[0016]
That is, the present invention provides the following electric double layer capacitor, polymer solid electrolyte / polarizable electrode laminate, and method for producing the electric double layer capacitor.
1) BET specific surface area 50m²/ G, the maximum primary particle size is 0.1 μm or less, the water content is 5000 ppm or less, containing at least one inorganic oxide fine particle in the range of 1 to 50% by weight, and the water content is 1000 ppm or less. An electric double layer capacitor comprising an organic electrolyte and / or a polymer solid electrolyte.
2) The electric double layer capacitor as described in 1 above, wherein the inorganic oxide fine particles are alumina-based fine particles and / or silica-based fine particles heat-treated at 100 to 1200 ° C.
3) The electric double layer capacitor as described in 2 above, wherein the alumina fine particles and / or the silica fine particles are aggregates of primary particles having a maximum particle size of 0.05 μm or less, and the average particle size of the aggregates is 0.01 to 5 μm. .
4) The electric double layer capacitor as described in any one of 1 to 3 above, wherein at least one polymer constituting the solid polymer electrolyte includes an oxyalkylene and / or urethane structure.
[0017]
5) At least one polymer is represented by the following general formula (1) and / or general formula (2):
[Chemical Formula 3]
CH₂= C (R¹COO-R²-(1)
[Formula 4]
CH₂= C (R^Three) CO [OR^Four]_xNHCOO-R^Five-(2)
[Wherein R¹And R^ThreeRepresents hydrogen or an alkyl group;
R², R^FourAnd R^FiveIs a divalent group having a linear, branched, or cyclic structure, which may contain a hetero atom,
x is 0 or an integer of 1 to 10.
However, when a plurality of polymerizable functional groups represented by the general formula (1) or (2) are contained in the same molecule, R in each polymerizable functional group¹, R², R^Three, R^Four, R^FiveAnd x may be the same or different. ]
5. The electric double layer capacitor as described in 4 above, which is a polymer obtained by polymerizing a thermal and / or actinic ray polymerizable compound having a polymerizable functional group represented by
6) The electric double layer capacitor as described in any one of 1 to 5 above, wherein the electrolyte salt in the organic electrolyte and / or polymer solid electrolyte is at least one selected from quaternary ammonium salts and quaternary phosphonium salts.
[0018]
7) An electric double layer capacitor comprising the organic electrolyte and / or polymer solid electrolyte according to any one of 1 to 6 above in a polarizable electrode material and / or an ion conductive layer disposed between polarizable electrodes.
8) (a) 50m BET specific surface area²/ G or more, at least one inorganic oxide fine particle having a maximum primary particle size of 0.1 μm or less and a water content of 5000 ppm or less, (b) at least one electrolyte salt, and (c) the heat described in 5 above and A composition comprising an actinic ray-polymerizable compound, comprising a heat and / or actinic-light-polymerizable composition containing 1 to 50% by weight of the inorganic oxide fine particles and having a water content of 1000 ppm or less. A polymer solid electrolyte / polarizable electrode laminate, which is disposed on a substrate comprising a polarizable electrode and then cured into a polymer solid electrolyte by heating and / or irradiation with actinic rays. Production method.
9) A method for producing an electric double layer capacitor, wherein a polarizable electrode is further laminated on the surface of the polymer solid electrolyte of the polymer solid electrolyte / polarizable electrode laminate produced by the method described in 8 above.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
The specific contents of the present invention will be described in detail below.
[1] Basic configuration of capacitor
First, the configuration of the electric double layer capacitor of the present invention will be described.
As shown in the schematic cross-sectional view of FIG. 1, the electric double layer capacitor of the present invention has a structure in which polarizable electrodes 2 are arranged in parallel and an ion conductive layer 3 is interposed therebetween. The outer surface of the polarizable electrode 2 is in contact with the current collector 1, lead wires 5 are drawn from each current collector, and the entire capacitor is sealed with an insulating resin sealant 4.
In FIG. 1, the current collector 1 is preferably made of a material having electronic conductivity and electrochemical corrosion resistance and having a specific surface area as large as possible. Examples of such materials include various metals and their sintered bodies, electron conductive polymers, carbon sheets and the like.
[0020]
As the polarizable electrode 2, a material obtained by dispersing and molding a polarizable material such as a carbon material in a polymer binder, or a material obtained by impregnating an organic electrolyte into the molded body thus obtained is used. As the polymer binder, polymer materials such as polyvinylidene fluoride, polyacrylonitrile, polytetrafluoroethylene, polyvinyl butyral, EPDM, and PMMA, and solid electrolyte materials can be used.
As the carbon material of the polarizable material, the larger the specific surface area, the larger the capacity of the electric double layer, which is preferable. For example, carbon blacks such as furnace black, thermal black (including acetylene black), channel black, activated carbon such as coconut shell charcoal, natural graphite, artificial graphite, so-called pyrolytic graphite produced by gas phase method, polyacene and C₆₀, C₇₀And various high-temperature polymer fired bodies such as polyvinylidene fluoride and polyvinyl alcohol.
The ion conductive layer 3 is specifically a separator and / or a polymer solid electrolyte membrane impregnated with an organic electrolyte. A spacer may be provided between the polarizable electrodes 2 to adjust the thickness of these separators or polymer solid electrolytes. However, spacers commonly used for electric double layer capacitors or the like may be used. Can be used. Usually, the thickness of the ion conductive layer 3 is about 5 to 100 μm.
[0021]
The electric double layer capacitor of the present invention is characterized by using an organic electrolytic solution and / or a polymer solid electrolyte containing an inorganic fine particle powder having a predetermined particle size range with a controlled water content in a predetermined range. . Specifically, the above-mentioned organic electrolyte and / or polymer solid electrolyte is used for the polarizable electrode 2 and / or the ion conductive layer 3 therebetween. By adopting such a configuration, impurities in the capacitor can be reduced or removed, and stability, safety, and reliability are improved. In addition, due to the interaction between the inorganic oxide fine particles and the electrolyte ions, ion mobility is improved and current characteristics are improved.
[0022]
In particular, when a polymer solid electrolyte is used, there is no leakage of liquid, no leakage, good heat resistance, and the safety and reliability as a capacitor are further increased. In addition, fine pores are generated between the inorganic oxide fine particles and the polymer, and when used in combination with the electrolyte, the free electrolyte is dispersed in the polymer solid electrolyte through the pores. Conductivity and mobility can also be increased.
The electric double layer capacitor of the present invention is not limited to the sheet type shown in FIG. 1, and may have any shape such as a chip type, a coin type, a square type, or a cylindrical type. Also, various sizes can be manufactured. According to the manufacturing method described later, since a uniform ion conductive layer can be easily laminated on the polarizable electrode, the area can be increased, and a counter electrode area of about 30 cm square can be easily obtained. Although the total thickness depends on the shape, it can be 1 mm or less, for example, about 0.5 mm in a sheet mold.
[0023]
[2] Organic electrolyte and polymer solid electrolyte
The organic electrolyte used in the electric double layer capacitor of the present invention comprises (a) inorganic oxide fine particles, (b) an organic solvent, and (c) an electrolyte salt as essential components.
Further, the solid electrolyte used in the electric double layer capacitor of the present invention includes (a) an inorganic oxide fine particle and (c) an electrolyte salt component, (d) a polymer component as an essential component, and (b) an organic solvent. May be included. Hereinafter, each component will be described in detail.
[0024]
(a) Inorganic oxide fine particles
(a-1) Inorganic oxide fine particles
The inorganic oxide fine particles added to the organic electrolyte or polymer solid electrolyte have a specific surface area of 10 m as a BET specific surface area.²/ G or more may be used, but it is desirable to have a larger specific surface area. In the present invention, the BET specific surface area is 50 m.²/ G or more fine particles.
Inorganic oxide fine particles (primary particles in the case of agglomerating to form secondary particles) having a maximum particle size of 1 μm or less are used, but smaller ones are preferred. In the present invention, the maximum diameter is 0.1 μm or less. Use fine particles.
In the present invention, it is necessary to use the inorganic oxide fine particle surface with the adsorbed water removed. Specifically, a water content measured by the Karl Fischer method is 5000 ppm or less.
[0025]
By making the inorganic oxide fine particles highly active with a high specific surface area and reduced adsorbed water, not only in the electrolyte and / or polymer solid electrolyte, but also impurities in the electric double layer capacitor, particularly moisture And free acid and free base can be adsorbed very well. As a result, a great effect is exhibited in reducing deterioration of the sealing material and other materials, and the life of the capacitor can be improved. Moreover, not only the impurity removal effect but also an unexpected effect that the interaction effect with the electrolyte ions becomes high and the ion mobility can be improved.
In general, when surface-active fine particles are used, the crystal particles are easily aggregated to form a secondary particle structure. However, by using such an aggregate, the impurity removal efficiency and ionic conductivity of the electrolyte solution described above are further improved. Results were found to be improved. In particular, an aggregate (secondary particle) having a maximum primary particle size of 0.05 μm or less and an average particle size of 0.01 μm to 5 μm is preferable.
[0026]
The water content of the inorganic oxide fine particles can be adjusted by heat-treating the fine particle powder. By heat-treating, the surface adsorbed water of the inorganic oxide fine particles is reduced, and not only the free moisture that diffuses to other materials is suppressed, but also the impurities of other materials can be adsorbed, improving the stability in the system. it can. Moreover, by moderately heat-treating, partial sintering is caused and there is an effect in secondary particle formation. The temperature and time of the heat treatment vary depending on the shape and type of the inorganic oxide fine particles to be used, but it may be about 2 to 300 hours in the range of 100 to 1200 ° C, and particularly preferably in the range of 500 to 1000 ° C.
The heat treatment temperature is preferably as high as possible. However, if it exceeds 1200 ° C., sintering of the inorganic oxide fine particles proceeds and the surface activity also decreases, which is not preferable. The atmosphere during the heat treatment is not particularly limited, and may be reduced pressure, air, or an inert atmosphere. However, after the heat treatment, it is necessary to handle in an atmosphere having a dew point of −30 ° C. or lower in order to prevent moisture re-adsorption. In particular, it is preferable to handle at a dew point of -50 ° C or lower.
The shape of the inorganic oxide fine particles used in the present invention is not particularly limited, and various shapes such as a spherical shape, an oval shape, a cubic shape, a rectangular parallelepiped shape, a cylindrical shape or a rod shape can be used.
[0027]
As the inorganic oxide fine particles used in the present invention, non-electron conductive and electrochemically stable particles are selected. Further, those having ion conductivity are more preferable.
Examples of such inorganic oxide fine particles include ionic conductivity such as alumina-based fine particles such as α, β, γ-alumina, silica-based fine particles, titania-based fine particles, magnesia-based fine particles, and composite oxide fine particles thereof. Non-conductive oxide fine particles are exemplified. Among these, alumina-based fine particles and silica-based fine particles are preferable because of their excellent stability and large interaction with electrolyte ions. In particular, the surface of the alumina-based fine particles has a high affinity with the electrolyte anion, and in particular, the cation binding can be reduced and the cation mobility can be improved.
[0028]
Specific examples of the alumina-based fine particles include α, β, and γ type Al obtained by various production methods such as a solid phase method and a gas phase method.₂O_ThreeLiAlO made by reacting fine particles and various inorganic substances such as Li salt₂Alumina-based composite oxide fine particles such as Among these, γ-type Al, such as aluminum oxide C (trade name) manufactured by Degussa and UA-5805 manufactured by Showa Denko Co., Ltd., which has a large specific surface area and large surface activity.₂O_ThreeFine particles and LiAlO₂However, it is suitable for the organic electrolyte and / or polymer solid electrolyte used in the electric double layer capacitor of the present invention.
Specific examples of the silica-based fine particles include Aerosil (trade name) manufactured by Degussa, which has a large specific surface area and a large surface activity.
[0029]
(a-2) Formulation in organic electrolyte and solid electrolyte
In the electric double layer capacitor of the present invention, when an organic electrolytic solution to which inorganic oxide fine particles are added is used, the viscosity is adjusted to be low. As other constituent components of the electric double layer capacitor, generally porous and microporous materials such as a polarizable electrode and a separator are used in order to efficiently perform an electrochemical reaction. When the viscosity of the electrolytic solution is too high, it is difficult to impregnate or combine them. Moreover, when the electrolyte solution viscosity increases, the ion mobility generally tends to decrease. For this reason, the viscosity of the organic electrolyte solution is 2000 cps or less at room temperature (the shear rate with a rotational viscometer is 20 to 400 s^-1In this case, it is preferably 1000 cps or less, more preferably 500 cps or less.
In consideration of the problem that if the amount of the inorganic oxide fine particles added is too high, the viscosity of the organic electrolyte is increased and the ionic conductivity is lowered. The preferred amount of the inorganic fine particles added is based on the weight of the organic electrolyte after the addition. It is 1 to 50% by weight, and a range of 1 to 30% by weight is particularly preferable.
[0030]
Even when the solid polymer electrolyte to which inorganic oxide fine particles are added is used in the electric double layer capacitor of the present invention, if the amount of inorganic oxide fine particles added is too large, the strength and ionic conductivity of the solid polymer electrolyte are reduced. Or a problem that film formation becomes difficult. A preferable addition amount is 1 to 50% by weight based on the weight of the polymer solid electrolyte after the addition, and a range of 1 to 30% by weight is particularly preferable.
By using the heat-treated inorganic oxide fine particles, the water content of the organic electrolyte and / or polymer solid electrolyte used in the electric double layer capacitor of the present invention is 1000 ppm or less (Karl Fischer titration value), preferably the water content Becomes 200 ppm or less (Karl Fischer titration value), and an electrolytic solution suitable for improving the performance of the electric double layer capacitor can be obtained.
[0031]
(b) Organic solvent
In the present invention, an organic solvent is used as the solvent itself in the organic electrolytic solution used for the electric double layer capacitor, and as a plasticizer in the polymer solid electrolyte.
As the organic solvent, a solvent having high solubility of the electrolyte salt, high affinity with the polymer, and stable in the operating voltage range of the electric double layer capacitor is preferable. That is, a compound having a large dielectric constant and a wide electrochemical stability range is suitable. Examples of such organic solvents include cyclic and / or chain carbonates such as ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, bismethoxyethyl carbonate, ethyl methoxyethyl carbonate, γ-butyrolactone, etc. Lactones, cyclic and / or chain ethers such as tetrahydrofuran, dioxolane and 1,2-dimethoxyethane, oligoethers such as triethylene glycol dimethyl ether and tetraethylene glycol dimethyl ether, aliphatics such as acetonitrile, benzonitrile and tolunitrile And / or nitrogen-containing compounds such as aromatic nitriles, dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, N-vinylpyrrolidone, etc. Sulfur compounds such as sulfolane, phosphoric acid esters, and the like. Among these, carbonates, ethers, oligoethers, and lactones are preferable, and carbonates and lactones are particularly preferable.
[0032]
(c) Electrolyte salt
The type of the electrolyte used for the organic electrolyte and / or polymer solid electrolyte used in the electric double layer capacitor of the present invention is not particularly limited, and a compound containing an ion desired to be a charge carrier may be used. It is desirable to include ions that have a large dissociation constant in the electrolytic solution and / or the polymer solid electrolyte and can easily form a polarizable electrode and an electric double layer. Such compounds include (CH_Three)_FourNBF_Four, (CH_ThreeCH₂)_FourNBF_Four, (CH_ThreeCH₂)_FourNClO_FourQuaternary ammonium salts such as pyridinium salts, (CH_Three)_FourPBF_Four, (CH_ThreeCH₂)_FourPBF_FourQuaternary phosphonium salts such as LiCF_ThreeSO_Three, LiPF₆LiClO_Four, LiI, LiBF_Four, LiSCN, LiAsF₆, LiN (CF_ThreeSO₂)₂, NaCF_ThreeSO_Three, NaPF₆, NaClO_Four, NaI, NaBF_Four, NaAsF₆, KCF_ThreeSO_Three, KPF₆, Alkali metal salts such as KI, AgClO_FourTransition metal salts such as, organic acids such as p-toluenesulfonic acid, and salts thereof. Of these, quaternary ammonium salts, pyridinium salts, and quaternary phosphonium salts are preferred from the viewpoints of high output voltage and a large dissociation constant. Among quaternary ammonium salts, (CH_ThreeCH₂) (CH_ThreeCH₂CH₂CH₂)_ThreeNBF_FourThose having different substituents on nitrogen of ammonium ions are preferable from the viewpoint of high solubility or dissociation constant in organic electrolytes and polymer solid electrolytes. The composite ratio of the electrolyte salt used in the organic electrolyte and / or polymer solid electrolyte is preferably 1 to 50% by weight, particularly preferably 5 to 30% by weight, based on the weight of the solvent and / or polymer. When the composite electrolyte salt is present at a ratio of 50% by weight or more, it is difficult to dissolve and the ion migration is greatly inhibited. Conversely, at a ratio of 1% by weight or less, the absolute amount of ions is insufficient and the ionic conductivity is low. Get smaller.
[0033]
(d) Solid electrolyte forming polymer
The polymer that is the main constituent of the polymer solid electrolyte used in the present invention must be non-electron-conducting and capable of absorbing and holding various organic polar solvents. Such polymers include polyalkylene oxide, polyalkylimine, polyacrylonitrile, poly (meth) acrylic acid ester, polyphosphazene, polyvinylidene fluoride, polyurethane, polyamide, polyester, polysiloxane and other polar polarities. These thermoplastic polymers and cross-linked polymers. In particular, a crosslinked polymer is suitable as a polymer for a polymer solid electrolyte because it has high strength after absorbing a solvent, has high solvent retention, and is a viscoelastic material. The term “crosslinking” as used herein includes, in addition to those in which the crosslinking chain is formed by a covalent bond, those in which the side chain is crosslinked by an ionic bond, a hydrogen bond, or the like, and those that have been physically crosslinked through various additives. Including.
[0034]
Among the above polymers, those containing an oxyalkylene such as polyalkylene oxide or polyurethane or a urethane structure in the molecular structure are preferable because they have good compatibility with various polar solvents and electrochemical stability. From the viewpoint of stability, those having a fluorocarbon group such as polyvinylidene fluoride in the molecular structure are also preferred.
Among the above polymers, the general formula (1) and / or (2)
[Chemical formula 5]
CH₂= C (R¹COO-R²-(1)
[Chemical 6]
CH₂= C (R^Three) CO [OR^Four]_xNHCOO-R^Five-(2)
A polymer obtained by curing at least one polymerizable compound having a polymerizable functional group represented by formula (2) by heating and / or irradiation with actinic rays is preferable because it is easy to form a film containing a solvent and has good film strength. . Among them, R in general formula (1) and / or general formula (2)²And / or R^FiveParticularly preferred are those containing an oxyalkylene group and / or a fluorocarbon or oxyfluorocarbon.
[0035]
There is no particular limitation on the method for synthesizing the compound having the functional group represented by the general formula (1) used in the solid polymer electrolyte of the present invention. For example, an acid chloride and a compound having a hydroxyl group at the terminal can be easily obtained by reacting, for example, oligooxyalkyleneol.
A compound having one functional group represented by the general formula (1) can be easily obtained by, for example, reacting an acid chloride with a monoalkyl oligooxyalkylene glycol in the following reaction formula at a molar ratio of 1: 1. be able to.
[Chemical 7]
CH₂= C (R¹) COCl + HO (CH₂CHR⁶O)_mR⁷
→ CH₂= C (R¹) COO (CH₂CHR⁶O)_mR⁷
Where R¹Represents the same meaning as in the general formula (1), and R⁶Represents H or an alkyl group having 10 or less carbon atoms, R⁷Represents an alkyl group having 10 or less carbon atoms, and m is an integer in the range of 1 to 1000, preferably 1 to 50.
[0036]
A compound having two functional groups represented by the general formula (1) can be easily obtained by reacting, for example, acid chloride and oligooxyalkylene glycol in the following reaction formula at a molar ratio of 2: 1. Can do.
[Chemical 8]
2CH₂= C (R¹) COCl + HO (CH₂CHR⁶O)_mH
→ CH₂= C (R¹) COO (CH₂CHR⁶O)_mCO (R¹) C = CH₂
Where R¹, R⁶And m have the same meaning as described above.
[0037]
The method for synthesizing the compound having a polymerizable functional group represented by the general formula (2) used in the polymer solid electrolyte of the present invention is not particularly limited.
[Chemical 9]
CH₂= C (R¹) CO [OR^Four]_xNCO
[Wherein R¹, R^FourAnd x represent the same meaning as in the general formula (2). It can obtain by reaction with the compound and oligoalkylene glycol represented. Where R^FourIs preferably
[Chemical Formula 10]
-(CH₂) P (CH (CH_Three)) Q-
[Wherein, p and q are each an integer of 0 to 5. However, when p = q = 0, x = 0. ] It is a bivalent group represented by this.
When p and q are 2 or more, -CH₂-And -CH (CH_Three)-May be arranged irregularly without being continuous.
[0038]
As a specific method, a compound having one ethylenically unsaturated group is, for example, a methacryloyl isocyanate compound (hereinafter abbreviated as MI) or an acryloyl isocyanate compound (hereinafter abbreviated as AI). And monoalkyl oligoalkylene glycol can be easily obtained by reacting at a molar ratio of 1: 1.
A compound having two ethylenically unsaturated groups can be easily obtained, for example, by reacting MIs or AIs with oligoalkylene glycol at a molar ratio of 2: 1.
[0039]
A compound having three ethylenically unsaturated groups is prepared by reacting, for example, MIs and / or AIs with a triol obtained by addition polymerization of alkylene oxide to a trihydric alcohol such as glycerin at a molar ratio of 3: 1. Can be easily obtained.
A compound having four ethylenically unsaturated groups is obtained by reacting, for example, MIs and / or AIs with a tetraol obtained by addition polymerization of alkylene oxide to a tetrahydric alcohol such as pentaerythritol at a molar ratio of 4: 1. This can be easily obtained.
The compound having 5 ethylenically unsaturated groups is prepared by reacting, for example, MIs and / or AIs with pentaol obtained by addition polymerization of α-D-glucopyranose with alkylene oxide at a molar ratio of 5: 1. This can be easily obtained.
A compound having 6 ethylenically unsaturated groups can be easily obtained by reacting, for example, MIs and / or AIs with hexaol obtained by addition polymerization of alkylene oxide to mannitol at a molar ratio of 6: 1. can get.
[0040]
General formula having a fluorocarbon group and / or an oxyfluorocarbon group
The method for synthesizing the compound having a polymerizable functional group represented by (1) and / or (2) is not particularly limited. For example, as a specific method, a compound having one polymerizable functional group may be MI or It is easily obtained by reacting AIs with monools such as 2,2,3,3,4,4,4-heptafluoro-1-butanol in the following reaction formula at a molar ratio of 1: 1. It is done.
Embedded image

The compound having two polymerizable functional groups is, for example, the following reaction formula of MIs or AIs and a diol such as 2,2,3,3-tetrafluoro-1,4-butanediol. And can be easily obtained by reacting at a molar ratio of 2: 1.
Embedded image

[0041]
A polymer obtained by polymerizing a compound having only one polymerizable functional group represented by the general formula (1) or (2) does not have a cross-linked structure and has insufficient film strength. Then there is a greater risk of short circuiting and it is better not to use it alone. Therefore, it is preferable to copolymerize and crosslink with a compound having two or more polymerizable functional groups represented by the general formula (1) or (2).
Considering the thin film strength of the polymer solid electrolyte, the number of polymerizable functional groups represented by the general formula (1) or (2) contained in one molecule is more preferably 3 or more.
Among the compounds having a polymerizable functional group represented by the general formula (1), the polymer obtained from the compound having a polymerizable functional group represented by the general formula (2) contains a urethane group, This is preferable because the polymerizability is good and the film strength is high when it is made into a thin film.
[0042]
A polymer preferable as a component of the composite electrolyte of the present invention is a polymer of at least one compound having a polymerizable functional group represented by the general formula (1) and / or the general formula (2), or copolymerization of the compound. It is obtained by polymerizing as a component. Even if the polymer used in the composite electrolyte of the present invention is a homopolymer of a compound having a polymerizable functional group represented by the general formula (1) and / or the general formula (2), two types belonging to the category It may be a copolymer of the above, or a copolymer of at least one compound belonging to the category and another polymerizable compound.
[0043]
There is no restriction | limiting in particular in the other polymerizable compound copolymerizable with the compound which has a polymeric functional group represented by the said General formula (1) and / or General formula (2).
For example, (meth) acrylamide compounds such as acrylamide, methacrylamide, N, N-dimethylacrylamide, N, N-dimethylmethacrylamide, acryloylmorpholine, methacryloylmorpholine, N, N-dimethylaminopropyl (meth) acrylamide, styrene, Examples thereof include styrene compounds such as α-methylstyrene, N-vinylamide compounds such as N-vinylacetamide and N-vinylformamide, and alkyl vinyl ethers such as ethyl vinyl ether.
[0044]
For the polymerization, a general method utilizing the polymerizability of the acryloyl group or methacryloyl group in the polymerizable compound can be employed. That is, these monomers alone, or a mixture of these monomers and other copolymerizable polymerizable compounds described above, a radical polymerization catalyst such as azobisisobutyronitrile and benzoyl peroxide, CF_ThreeProtonic acid such as COOH, BF_ThreeAlCl_ThreeIt is possible to carry out radical polymerization, cationic polymerization or anionic polymerization using a cationic polymerization catalyst such as Lewis acid or the like, or an anionic polymerization catalyst such as butyl lithium, sodium naphthalene or lithium alkoxide. In addition, some polymerizable compounds can be radically polymerized only by heating in an oxygen-free state.
[0045]
The polymer used in the polymer solid electrolyte of the present invention preferably has an oxyalkylene structure, but in that case, the number of oxyalkylene chains (that is, R in the general formula (1))²R in the general formula (2)^FiveThe repeating number n) of the oxyalkylene group contained therein is preferably in the range of 1-1000, particularly preferably in the range of 5-100.
The organic solvent described above is preferably added to the polymer solid electrolyte of the present invention. The higher the content of the solvent in the polymer solid electrolyte, the easier the electrolyte salt dissociates or the ions diffuse, and the ionic conductivity in that case increases, but the mechanical strength of the membrane decreases. A preferable addition amount is 0.5 to 12 times or less and 1 to 8 times or less the weight of the polymer in the polymer solid electrolyte of the present invention.
[0046]
[3] Manufacturing method of electric double layer capacitor
The organic electrolyte or polymer solid electrolyte thus prepared is used as a polarizable electrode of an electric double layer capacitor and / or an ion conductive layer provided therebetween as described above.
When used for a polarizable electrode, a polarizable material such as activated carbon or graphite is mixed with a conventional polymer material, formed into a film, and then cured by drying, light irradiation, heating, etc. Impregnated with an organic electrolyte containing fine particles. Alternatively, the composition described above, wherein at least one inorganic oxide fine particle or at least one electrolyte salt is added to at least one of the (meth) acryloyl compound having a polymerizable functional group described in detail in [2] above. The material is mixed with a polarizable material and, if necessary, a polymerization initiator, formed into a film, and then cured by drying, light irradiation, heating, or the like.
[0047]
When used for the ion conductive layer, a conventional separator material, for example, a porous film described later is impregnated with an organic electrolytic solution containing the above inorganic fine particles. Alternatively, a method of polymerizing and curing the polymerizable composition described above on various substrates by heating and / or irradiation with actinic rays can be uniformly formed, and film thickness control is simple and recommended. it can. This self-supporting film may be further impregnated with an organic electrolyte containing the above-mentioned inorganic fine particles.
[0048]
In any of the above, the polymer solid electrolyte can be improved in strength by being combined with another porous polymer film. However, depending on the type of polymer to be used, the film shape, and the composite ratio, it may cause a decrease in ionic conductivity and a deterioration in stability, so it is necessary to select a suitable one. Examples of porous polymer films used include porous polyolefin films such as polypropylene nonwoven fabrics and reticulated polyolefin sheets such as polyethylene nets, polyolefin microporous films such as Celgard (trade name), nylon nonwoven fabrics, and polyester nets. Although mentioned, a porous film made of polyolefin is preferable in terms of stability. The porosity should be about 10 to 90%, but it should be as large as possible as long as the strength permits, so the preferable porosity range is 40 to 90%.
[0049]
The temperature for the heat polymerization depends on the type of the polymerizable compound and the type of the initiator, but may be any temperature at which the polymerization occurs, and is usually performed in the range of 0 ° C to 200 ° C. Even in the case of polymerization by actinic ray irradiation, depending on the type of polymerizable compound, etc., for example, using an actinic ray initiator such as benzylmethyl ketal and benzophenone, ultraviolet light of several mW or more, electron beam, γ ray, etc. Can be polymerized by irradiation.
An ion conducting layer is sandwiched between polarizable electrodes thus obtained, and the entire current collector with lead wires connected to the outer surface of the polarizable electrode is overlaid, and the whole is made of an insulating resin such as a polyolefin resin or an epoxy resin. An electric double layer capacitor is formed by sealing.
Alternatively, a polarizable electrode is provided on a structure or support for an electric double layer capacitor made of a metal such as SUS, polypropylene, aluminum laminate heat-sealing resin, polyimide, Eval, or a ceramic material such as conductive or insulating glass. The polymerizable composition may be cured after inserting the spacer and injecting the electrolyte or the polymerizable composition therebetween.
[0050]
In the present invention, the polymer electrolyte membrane may be directly formed on the polarizable electrode containing the inorganic fine powder according to the present invention. According to this method, an electrode-polymer solid electrolyte laminate in which both are in close contact can be obtained, and an electric double layer capacitor can be produced simply by bonding another polarizable electrode with the polymer solid electrolyte membrane interposed therebetween. .
Since the electric double layer capacitor of the present invention uses an organic electrolyte and / or a polymer solid electrolyte to which specific inorganic oxide fine particles having a high specific surface area and a low water content are added, impurities that adversely affect the capacitor characteristics Can be trapped, and can be a stable, reliable and long-life electric double layer capacitor.
[0051]
Furthermore, the added inorganic oxide fine particles have a large interaction with the electrolyte ions, the ion mobility in the organic electrolyte and / or polymer solid electrolyte is improved, and an electric double layer capacitor having a large extraction current is obtained. be able to.
In the present invention, a polymerizable compound having a (meth) acrylic group and / or a urethane (meth) acrylic group is excellent in curing characteristics, and these compounds, fine alumina particles, an electrolyte salt, and / or an organic solvent are added. By placing the mixed polymerizable composition on the electrode and then curing it by heating and / or actinic ray irradiation, a polymer solid electrolyte / polarizable electrode laminate optimum for an electric double layer capacitor can be easily produced. Therefore, by using the polymer solid electrolyte / polarizable electrode laminate, a stable, reliable and long-life electric double layer capacitor can be easily obtained. It is also easy to improve the capacity by increasing the electrode area and decreasing the electrode interval.
[0052]
【Example】
Hereinafter, the present invention will be described in detail by way of typical examples. Note that these are merely illustrative examples, and the present invention is not limited thereto. In the following examples, reference examples, and comparative examples, the water content was measured by the Karl Fischer method.
[0053]
Example 1: Synthesis of polymerizable compound (compound 3)
According to the following reaction formula, compound 1 which is a glycerin ester and compound 2 which is a methacrylate containing an isocyanate group were reacted to obtain thermopolymerizable compound 3.
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Specifically, after 50.0 g of Compound 1 (KOH value 34.0 mg / g, p / q = 7/3) and 4.6 g of Compound 2 were dissolved in 100 ml of well-purified THF in a nitrogen atmosphere, 0.44 g of dibutyltin was dissolved. Dilaurate was added. Then, the colorless viscous liquid was obtained by making it react at 25 degreeC for about 15 hours. That¹From the results of 1 H-NMR, IR, and elemental analysis, compound 1 and compound 2 reacted 1 to 3, and the isocyanate group of compound 2 disappeared and a urethane bond was formed, and compound 3 was formed. I found out.
[0054]
Reference Example 1: Preparation of solid electrolyte film (a)
Compound 3 (1.0 g), ethylene carbonate (EC) (1.8 g), propylene carbonate (PC) (4.2 g), tetraethylammonium tetrafluoroborate (TEAB) (0.8 g), and 2,4,6-trimethylbenzoyl Diphenylphosphine oxide (trade name Lucillin TPO, manufactured by BASF) (0.005 g) was mixed well in an argon atmosphere to obtain a photopolymerizable composition. The water content of this composition was 100 ppm.
This photopolymerizable composition was applied on a PET film under an argon atmosphere, and then irradiated with a chemical fluorescent lamp (FL20S.BL, manufactured by Sankyo Electric Co., Ltd.) for 10 minutes. A compound impregnated with an EC / PC electrolyte solution A tripolymer film (“solid electrolyte film (a)”) was obtained as a free standing film of about 30 μm. When the ionic conductivity at 25 ° C. and −20 ° C. of this film was measured by the impedance method, it was 7.3 × 10 5 respectively.^-31.6 × 10^-3S / cm.
[0055]
Example 2: Preparation of alumina-containing solid electrolyte film (A)
High purity γ-alumina (trade name: UA5805, crystal particle size: 0.03 μm, average secondary particle size: 1.8 μm, BET specific surface area: 80 m, heat-treated at 1000 ° C. for 2 hours in a dry air atmosphere²/ G) (0.33 g), Compound 3 (1.0 g), EC (1.8 g), PC (4.2 g), TEAB (1.2 g), and Lucillin TPO (BASF) (0.005 g) in an argon atmosphere Mix well to obtain a photopolymerizable composition. The water content of this composition was 30 ppm.
This photopolymerizable composition was applied on a PET film under an argon atmosphere, and then irradiated with a chemical fluorescent lamp (FL20S.BL, manufactured by Sankyo Electric Co., Ltd.) for 10 minutes. As a result, Compound 3 impregnated with an EC / PC electrolyte was used. A polymer / UA5805 composite film (“solid electrolyte film (A)”) was obtained as a free standing film of about 30 μm. When the ionic conductivity of this film at 25 ° C. and −20 ° C. was measured by the impedance method, it was 7.8 × 10 6 respectively.^-3, 1.8 × 10^-3S / cm.
[0056]
Reference Example 2: Preparation of solid electrolyte film (b)
High purity γ-alumina (trade name: UA5805, crystal particle size: 0.03 μm, average secondary particle size: 1.8 μm, BET specific surface area: 80 m, heat-treated at 80 ° C. for 24 hours in a dry air atmosphere²/ g) (0.33 g), Compound 3 (1.0 g), EC (1.8 g), PC (4.2 g), TEAB (1.2 g), and Lucillin TPO (manufactured by BASF) (0.005 g) in an argon atmosphere Were mixed well to obtain a photopolymerizable composition. The water content of this composition was 1100 ppm.
This photopolymerizable composition was applied on a PET film under an argon atmosphere, and then irradiated with a chemical fluorescent lamp (FL20S.BL, manufactured by Sankyo Electric Co., Ltd.) for 10 minutes. As a result, Compound 3 impregnated with an EC / PC electrolyte was used. Polymer / low-temperature treated UA5805 composite film (“solid electrolyte film (b)” was obtained as a free-standing film of about 30 μm. The ionic conductivity of this film at 25 ° C. and −20 ° C. was measured by the impedance method. , 7.0 × 10 respectively^-31.4 × 10^-3S / cm.
[0057]
Example 3: Preparation of alumina-containing solid electrolyte film (B)
Aluminum oxide C (trade name, manufactured by Nippon Aerosil Co., Ltd., crystal particle size: 0.013 μm, average secondary particle size: 0.11 μm (SEM observation), BET specific surface area as alumina fine particles instead of UA5805 at 1000 ° C. 100m²/ G) A photopolymerizable composition was obtained in the same manner as in Example 2 except that (0.33 g) was added. The water content of this composition was 35 ppm.
The photopolymerizable composition was coated and irradiated with light in the same manner as in Example 2 to obtain a compound 3 polymer / aluminum oxide C composite film (“solid electrolyte film (B)”) impregnated with an EC / PC electrolyte. Obtained as a free standing film of about 30 μm. When the ionic conductivity of this film at 25 ° C. and −20 ° C. was measured by the impedance method, it was 8.3 × 10 6 respectively.^-3, 2.3 × 10^-3S / cm.
[0058]
Reference Example 3: Preparation of solid electrolyte film (c)
A thermopolymerizable composition was obtained in the same manner as in Reference Example 1 except that benzoyl peroxide (BPO) (0.04 g) was added instead of lucillin TPO (0.005 g) as an initiator. The water content of this composition was 35 ppm.
This thermopolymerizable composition was coated on a PET film in an argon atmosphere, then covered with a PP film, and heated on a hot plate at 80 ° C. for 1 hour to obtain a compound 3 polymer impregnated with an EC / PC electrolyte. A film (“solid electrolyte film (c)”) was obtained as a free standing film of about 30 μm. When the ionic conductivity of this film at 25 ° C. and −20 ° C. was measured by the impedance method, it was 7.8 × 10 6 respectively.^-3, 1.5 × 10^-3S / cm.
[0059]
Reference Example 4: Preparation of solid electrolyte film (d)
Α-Alumina (trade name: A-420, crystal particle size: 0.4 μm, average secondary particle size: 3.2 μm, BET specific surface area: 2.2 heat-treated at 1000 ° C. for 2 hours in a dry air atmosphere m²/ g) (0.33 g), Compound 3 (1.0 g), EC (1.8 g), PC (4.2 g), TEAB (1.2 g), and Lucillin TPO (manufactured by BASF) (0.005 g) in an argon atmosphere Were mixed well to obtain a photopolymerizable composition. The water content of this composition was 40 ppm.
This photopolymerizable composition was applied on a PET film under an argon atmosphere, and then irradiated with a chemical fluorescent lamp (FL20S.BL, manufactured by Sankyo Electric Co., Ltd.) for 10 minutes. As a result, Compound 3 impregnated with an EC / PC electrolyte was used. Polymer / low-temperature treatment A-420 composite film ("solid electrolyte film (d)" was obtained as a free-standing film of about 30 μm. Ion conductivity of this film at 25 ° C and -20 ° C was measured by the impedance method. As a result, 6.0 × 10 respectively^-3, 1.0 × 10^-3S / cm.
[0060]
Example 4: Preparation of alumina-containing solid electrolyte film (C)
A photopolymerizable composition was obtained in the same manner as in Example 3 except that the same amount of tetraethylphosphonium tetrafluoroborate (TEPB) was used instead of TEAB as the electrolyte salt. The water content of this composition was 30 ppm.
By applying this photopolymerizable composition in the same manner as in Example 3 and irradiating with light, a compound 3 polymer / aluminum oxide C composite film impregnated with an electrolytic solution (“solid electrolyte film (C)”) was about 30 μm. Obtained as a self-supporting film. When the ionic conductivity of this solid electrolyte at 25 ° C. and −20 ° C. was measured by the impedance method, it was 6.30 × 10 6.^-3, 1.0 × 10^-3S / cm.
[0061]
Example 5: Synthesis of polymerizable compound (compound 5)
Embedded image

20 g of compound 4 (2,2,3,3,4,4,4-heptafluoro-1-butanol, manufactured by Aldrich) and compound 6 (15.5 g) were mixed with 100 ml of well-purified THF in a nitrogen atmosphere, and then dibutyl. Add tindilaurate (0.66 g). Then, it was made to react at 25 degreeC for about 15 hours, and the compound 5 was obtained as a colorless viscous liquid. That¹From the results of 1 H-NMR, IR, and elemental analysis, it was found that compound 4 and compound 6 reacted one-to-one, and further, the isocyanate group of compound 6 disappeared and a urethane bond was formed. .
[0062]
Example 6: Preparation of alumina-containing solid electrolyte film (D)
Compound 5 (0.5 g), Compound 3 (0.3 g), aluminum oxide C (0.22 g) heat treated at 1000 ° C., EC (1.8 g), PC (4.2 g), TEAB (1.2 g) and Lucillin TPO (manufactured by BASF) ) (0.005 g) was thoroughly mixed in an argon atmosphere to obtain a photopolymerizable composition. The water content of this composition was 20 ppm.
This photopolymerizable composition was applied on a PET film under an argon atmosphere, and then irradiated with a chemical fluorescent lamp (FL20S.BL manufactured by Sankyo Electric Co., Ltd.) for 10 minutes. As a result, compound 5+ impregnated with EC / PC electrolyte was used. A compound 3 copolymer / UA5805 composite film (“solid electrolyte film (D)”) was obtained as a free-standing film of about 30 μm. When the ionic conductivity of this film at 25 ° C. and −20 ° C. was measured by the impedance method, it was 6.0 × 10 6 respectively.^-3, 1.0 × 10^-3S / cm.
[0063]
Example 7: Preparation of silica-containing solid electrolyte film (E)
Silica fine particles made of Nippon Aerosil (Aerosil 200, crystal particle size: 0.012 μm, average secondary particle size: about 0.1 μm (SEM observation), BET specific surface area: 180 m, heat-treated at 1000 ° C. instead of UA5805 as inorganic oxide fine particles²/ G) A photopolymerizable composition was obtained in the same manner as in Example 2 except that (0.33 g) was added. The water content of this composition was 30 ppm.
When this photopolymerizable composition was applied and irradiated with light in the same manner as in Example 2, a compound 3 polymer / aluminum oxide C composite film (“solid electrolyte film (E)”) impregnated with an EC / PC electrolyte was obtained. Obtained as a free standing film of about 30 μm. When the ionic conductivity of this film at 25 ° C. and −20 ° C. was measured by the impedance method, it was 6.6 × 10 6 respectively.^-31.6 × 10^-3S / cm.
[0064]
Example 8: Preparation of alumina-containing organic electrolyte (A)
Aluminum oxide C (0.33 g), PC (6.0 g), and TEAB (0.80 g) heat-treated at 1000 ° C. were mixed well at room temperature in an argon atmosphere to prepare an electrolytic solution (“organic electrolytic solution (A)”). The water content of this electrolytic solution was 20 ppm. When the ionic conductivity of this electrolytic solution at 25 ° C. and −20 ° C. was measured by the impedance method, it was 10.0 × 10 respectively.^-3, 3.0 × 10^-3S / cm. The viscosity with a rotational viscometer is 150 cps (380 s^-1)Met.
[0065]
Example 9: Preparation of alumina-containing organic electrolyte (B)
1000 ° C. heat-treated aluminum oxide C (0.33 g), PC 3.0 g, γ-butyrolactone (γBL) (3.0 g), TEAB (0.80 g) were mixed well at room temperature in an argon atmosphere, and an electrolyte (“organic electrolyte ( B) ") was prepared. The water content of this electrolytic solution (Karl Fischer method) was 70 ppm. When the ionic conductivity of this electrolytic solution at 25 ° C. and −20 ° C. was measured by the impedance method, it was 12.0 × 10 6 respectively.^-3, 3.0 × 10^-3S / cm. The viscosity with a rotational viscometer is 120 cps (380 s^-1)Met.
[0066]
Table 1 summarizes the components of the solid electrolyte films (A to E), (a to c) and organic electrolytes (A and B) produced in Examples 1 to 9 and Reference Examples 1 to 3.
[0067]
[Table 1]

[0068]
Example 10: Production of activated carbon electrode (a)
An excess N-methylpyrrolidone solution was added to a mixture of coconut shell activated carbon and polyvinylidene fluoride in a weight ratio of 9.0: 1.0 to obtain a gel composition. This composition was applied on a stainless steel foil to a thickness of about 150 μm with a size of 15 mmφ. It vacuum-dried at about 100 degreeC for 10 hours, and obtained the activated carbon electrode (24.8mg).
[0069]
Example 11: Manufacture of coin-type electric double layer capacitor
In an argon atmosphere glove box, the activated carbon electrode (a) (24.8 mg) produced in Example 10 was impregnated with the organic electrolyte (B) [aluminum oxide C-added electrolyte (TEAB / PC + γBL)] prepared in Example 9 Two prepared electrodes were prepared. Next, a polyolefin microporous film (16 mmφ, aperture ratio of about 65%, thickness 25 μm) impregnated with the aluminum oxide C-added electrolyte (Example 10) was bonded to one electrode, and another sheet The electrodes were bonded together and sealed in a 2016 coin-type can (diameter 20 mm, thickness 1.6 mm) to obtain a coin-type electric double layer capacitor.
When this capacitor was charged and discharged at an operating voltage of 0 to 2.5 V and a current of 0.35 mA and 3.5 mA, the maximum capacities were 850 mF and 770 mF, respectively. Moreover, even if charging / discharging was repeated 100 times at 3.5 mA, there was almost no change in capacity.
[0070]
Example 12: Manufacture of coin-type electric double layer capacitor
A coin-type (2016) electric double layer capacitor was prepared in the same manner as in Example 11 except that the organic electrolyte (A) [aluminum oxide C-added electrolyte (TEAB / PC)] prepared in Example 8 was used as the electrolyte. Obtained.
When this capacitor was charged and discharged at an operating voltage of 0 to 2.5 V and a current of 0.35 mA and 3.5 mA, the maximum capacity was 830 mF and 660 mF. Moreover, even if charging / discharging was repeated 100 times at 3.5 mA, there was almost no change in capacity.
[0071]
Example 13: Production of activated carbon electrode (b)
An excess N-methylpyrrolidone solution was added to a mixture of coconut shell activated carbon and polyvinylidene fluoride in a weight ratio of 9.0: 1.0 to obtain a gel composition. This composition was applied on a stainless steel foil in a size of 10 mm × 10 mm to a thickness of about 150 μm. It vacuum-dried at about 100 degreeC for 10 hours, and obtained the activated carbon electrode (14.0 mg).
[0072]
Example 14: Manufacture of thin electric double layer capacitor
In the argon atmosphere glove box, two electrodes were prepared by impregnating the activated carbon electrode (b) (14.0 mg) 10 mm × 10 mm produced in Example 13 with the electrolyte (1M TEAB / PC + EC (3: 1)). . Next, the solid electrolyte film B [compound 3 polymer / aluminum oxide C composite film] (12 mm × 12 mm) produced in Example 3 was bonded to one electrode, and another electrode was bonded to the capacitor end. By sealing the part with an epoxy resin, a thin electric double layer capacitor having the configuration shown in FIG. 1 was produced.
When this capacitor was charged and discharged at an operating voltage of 0 to 2.5 V, a current of 0.2 mA, and 2.0 mA, the maximum capacity was 470 mF and 423 mF. Moreover, even if charging / discharging was repeated 100 times at 2.0 mA, there was almost no change in capacity.
[0073]
Example 15: Production of a thin electric double layer capacitor
Solid electrolyte film produced in Example 4 as a polymer solid electrolyte film (C) [TEPB compound 3 polymer / aluminum oxide C composite film] (12 mm × 12 mm), 1M TEPB / PC + EC (3: 1) as electrolyte A thin electric double layer capacitor was produced in the same manner as in Example 14 except that (1) was used. When this capacitor was charged and discharged at an operating voltage of 0 to 2.5 V, a current of 0.2 mA, and 2.0 mA, the maximum capacity was 450 mF and 360 mF. Moreover, even if charging / discharging was repeated 100 times at 2.0 mA, there was almost no change in capacity.
[0074]
Example 16: Manufacture of thin electric double layer capacitor
The solid electrolyte film manufactured in Example 6 was used as the polymer solid electrolyte film (D) [Example 5] except that [compound 5 + compound 3 copolymer / aluminum oxide C composite film] (12 mm × 12 mm) was used. A thin electric double layer capacitor was manufactured.
When this capacitor was charged and discharged at an operating voltage of 0 to 2.5 V and a current of 0.2 mA and 2.0 mA, the maximum capacity was 450 mF and 410 mF. Moreover, even if charging / discharging was repeated 100 times at 2.0 mA, there was almost no change in capacity.
[0075]
Example 17: Production of thin electric double layer capacitor
Solid electrolyte film produced in Example 6 as a polymer solid electrolyte film (D) [Compound 5 + Compound 3 copolymer / aluminum oxide C composite film] (12 mm × 12 mm), Organic electrolyte B [aluminum oxide as electrolyte] A thin electric double layer capacitor was produced in the same manner as in Example 14 except that C-added TEAB / PC + γBL (Example 9)] was used.
When this capacitor was charged and discharged at an operating voltage of 0 to 2.5 V, a current of 0.2 mA, and 2.0 mA, the maximum capacity was 480 mF and 430 mF. Moreover, even if charging / discharging was repeated 100 times at 2.0 mA, there was almost no change in capacity.
[0076]
Comparative Example 1: Production of thin electric double layer capacitor
A thin electric double layer capacitor was produced in the same manner as in Example 14 except that the solid electrolyte film (a) [compound 3 polymer film] (12 mm × 12 mm) produced in Reference Example 1 was used as the polymer solid electrolyte film. did.
When this capacitor was charged and discharged at an operating voltage of 0 to 2.5 V and a current of 0.2 mA and 2.0 mA, the maximum capacity was 450 mF and 350 mF. Moreover, when charge / discharge was repeated 100 times at 2.0 mA, the capacity decreased by 10%.
[0077]
Comparative Example 2: Production of thin electric double layer capacitor
As the polymer solid electrolyte film, the thin electrolyte was manufactured in the same manner as in Example 14 except that the solid electrolyte film (b) [compound 3 polymer / low-temperature heat treatment UA5805 composite film] (12 mm × 12 mm) produced in Reference Example 2 was used. A double layer capacitor was manufactured.
When this capacitor was charged and discharged at an operating voltage of 0 to 2.5 V and a current of 0.2 mA and 2.0 mA, the maximum capacity was 450 mF and 400 mF. Moreover, when charge / discharge was repeated 100 times at 2.0 mA, the capacity decreased by 30%.
[0078]
Example 18: Production of a thin electric double layer capacitor
As the polymer solid electrolyte film, the thin electrolyte film was prepared in the same manner as in Example 14 except that the solid electrolyte film (E) [compound 3 polymer / silica fine particle composite film] (12 mm × 12 mm) produced in Example 7 was used. A multilayer capacitor was manufactured. When this capacitor was charged and discharged at an operating voltage of 0 to 2.5 V, a current of 0.2 mA, and 2.0 mA, the maximum capacity was 440 mF and 360 mF. Moreover, even if charging / discharging was repeated 100 times at 2.0 mA, there was almost no change in capacity.
[0079]
Example 19: Production of an all-solid thin electric double layer capacitor
An electrode obtained by impregnating the activated carbon electrode (b) (14 mg) 10 mm × 10 mm produced in Example 13 with the thermopolymerizable composition (compound 3 / TEAB / PC + EC) prepared in Reference Example 3 in an argon atmosphere glove box. Two were prepared. Next, the solid electrolyte film B [compound 3 polymer / aluminum oxide C composite film] (12 mm × 12 mm) produced in Example 3 was bonded to one electrode, and another electrode was bonded to the capacitor end. The part was sealed with an epoxy resin, and the thermopolymerizable composition was heated and polymerized at 80 ° C. for 1 hour to produce an all-solid thin electric double layer capacitor having the configuration shown in FIG.
When this capacitor was charged and discharged at an operating voltage of 0 to 2.5 V, a current of 0.2 mA, and 2.0 mA, the maximum capacity was 400 mF and 200 mF. Moreover, there was almost no change in capacity even when charging and discharging were repeated 100 times at 0.2 mA.
[0080]
Example 20: Manufacture of thin electric double layer capacitor
In the argon atmosphere glove box, two electrodes were prepared by impregnating the activated carbon electrode (b) (14 mg) 10 mm × 10 mm produced in Example 13 with an electrolyte (1M TEAB / PC + EC (3: 1)). Next, the compound 3 polymer / aluminum oxide C-based photopolymerizable composition prepared in Example 3 was applied on one electrode, and then irradiated with a chemical fluorescent lamp for 10 minutes. A coalescence / aluminum oxide C composite film was formed. Next, another thin electrode was laminated on the film, and the capacitor end was sealed with an epoxy resin to produce a thin electric double layer capacitor as shown in FIG.
When this capacitor was charged and discharged at an operating voltage of 0 to 2.5 V, a current of 0.2 mA, and 2.0 mA, the maximum capacity was 480 mF and 446 mF. Moreover, even if charging / discharging was repeated 100 times at 2.0 mA, there was almost no change in capacity.
[0081]
Table 2 summarizes the components of the thin electric double layer capacitors produced in Examples 14 to 20 and Comparative Examples 1 and 2 and the results of repeated use.
[0082]
[Table 2]

[0083]
【The invention's effect】
Since the electric double layer capacitor of the present invention uses an organic electrolyte and / or a polymer solid electrolyte to which specific inorganic oxide fine particles having a high specific surface area and a low water content are added, it is stable and highly reliable, An electric double layer capacitor having a long life and a large extraction current can be obtained.
According to the present invention, a polymerizable compound having a (meth) acrylic group and / or a urethane (meth) acrylic group having excellent curing characteristics is cured by heating and / or actinic ray irradiation, so that it is optimal for an electric double layer capacitor. A solid polymer electrolyte / polarizable electrode laminate can be easily produced. Furthermore, by using the polymer solid electrolyte / polarizable electrode laminate, an electric double layer capacitor that is stable, highly reliable, and has a long life can be easily obtained.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of an embodiment of a thin electric double layer capacitor shown as an example of the electric double layer capacitor of the present invention.
[Explanation of symbols]
1 Current collector
Bipolar electrode
3 Ion conduction layer
4 Insulating resin sealant
5 Lead wire

Claims (9)

At least one kind of inorganic oxide fine particles having a BET specific surface area of 50 m ² / g or more, a maximum primary particle size of 0.1 μm or less, and a heat treatment at 500 to 1200 ° C. and a water content of 5000 ppm or less. An electric double layer capacitor comprising an organic electrolytic solution and / or a polymer solid electrolyte that is contained in the range of% by weight and has a water content of 200 ppm or less.   The electric double layer capacitor according to claim 1, wherein the inorganic oxide fine particles are alumina-based fine particles and / or silica-based fine particles.   3. The electric double electrode according to claim 2, wherein the alumina-based fine particles and / or the silica-based fine particles are aggregates of primary particles having a maximum particle size of 0.05 μm or less, and the average particle size of the aggregate is 0.01 to 5 μm. Multilayer capacitor.   The electric double layer capacitor according to any one of claims 1 to 3, wherein at least one polymer constituting the polymer solid electrolyte includes an oxyalkylene and / or urethane structure. At least one polymer is represented by the following general formula (1) and / or general formula (2):
^{_{CH 2 = C (R 1)}} COO-R 2 - (1)
^{_{CH 2 = C (R 3)}} CO [OR 4] x NHCOO-R 5 - (2)
[Wherein R ¹ and R ³ represent hydrogen or an alkyl group, and R ² , R ⁴ and R ^{5 each} have a linear, branched, or cyclic structure which may contain a hetero atom. And x is an integer of 0 or 1 to 10. However, when a plurality of polymerizable functional groups represented by the general formula (1) or (2) are contained in the same molecule, R ¹ , R ² , R ³ , R ⁴ , R ⁵ and x may be the same or different. The electric double layer capacitor according to claim 4, which is a polymer obtained by polymerizing a thermal and / or actinic ray polymerizable compound having a polymerizable functional group represented by the formula:   The electric double layer capacitor according to any one of claims 1 to 5, wherein the electrolyte salt in the organic electrolyte and / or the polymer solid electrolyte is at least one selected from a quaternary ammonium salt and a quaternary phosphonium salt.   An electric double layer capacitor comprising the organic electrolyte and / or polymer solid electrolyte according to any one of claims 1 to 6 in an ion conductive layer disposed between a polarizable electrode material and / or a polarizable electrode . (A) at least one inorganic oxide fine particle having a BET specific surface area of 50 m ² / g or more, a maximum primary particle size of 0.1 μm or less, and a heat treatment at 500 to 1200 ° C. and having a water content of 5000 ppm or less; b) a composition comprising at least one electrolyte salt, and (c) the heat and / or actinic ray polymerizable compound according to claim 5, comprising the inorganic oxide fine particles in a range of 1 to 50% by weight, After placing a heat and / or actinic ray polymerizable composition having a water content of 200 ppm or less on a substrate comprising a polarizable electrode, the composition is cured by heating and / or actinic ray irradiation to form a polymer solid. A method for producing a polymer solid electrolyte / polarizable electrode laminate, characterized by comprising an electrolyte.   A method for producing an electric double layer capacitor, further comprising: laminating a polarizable electrode on the surface of the solid polymer electrolyte of the solid polymer electrolyte / polarizable electrode laminate produced by the method according to claim 8.

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