JP3208183B2 - Lithium secondary battery - Google Patents
Lithium secondary batteryInfo
- Publication number
- JP3208183B2 JP3208183B2 JP22073492A JP22073492A JP3208183B2 JP 3208183 B2 JP3208183 B2 JP 3208183B2 JP 22073492 A JP22073492 A JP 22073492A JP 22073492 A JP22073492 A JP 22073492A JP 3208183 B2 JP3208183 B2 JP 3208183B2
- Authority
- JP
- Japan
- Prior art keywords
- negative electrode
- battery
- binder
- current collector
- secondary battery
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 title claims description 19
- 229910052744 lithium Inorganic materials 0.000 title claims description 19
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 41
- 239000002033 PVDF binder Substances 0.000 claims description 20
- 239000011230 binding agent Substances 0.000 claims description 20
- 229920002981 polyvinylidene fluoride Polymers 0.000 claims description 20
- 229920000193 polymethacrylate Polymers 0.000 claims description 16
- 239000000203 mixture Substances 0.000 claims description 13
- 229920003229 poly(methyl methacrylate) Polymers 0.000 claims description 7
- 239000004926 polymethyl methacrylate Substances 0.000 claims description 7
- 229910052751 metal Inorganic materials 0.000 description 12
- 239000002184 metal Substances 0.000 description 12
- 229910052799 carbon Inorganic materials 0.000 description 9
- 239000000843 powder Substances 0.000 description 6
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 239000007773 negative electrode material Substances 0.000 description 4
- 229920001483 poly(ethyl methacrylate) polymer Polymers 0.000 description 4
- 238000002360 preparation method Methods 0.000 description 4
- 229910052782 aluminium Inorganic materials 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 239000006185 dispersion Substances 0.000 description 3
- 239000003792 electrolyte Substances 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 229910021382 natural graphite Inorganic materials 0.000 description 3
- -1 LiCrO 2 Inorganic materials 0.000 description 2
- 239000000571 coke Substances 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 239000011889 copper foil Substances 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 239000011888 foil Substances 0.000 description 2
- 229910002804 graphite Inorganic materials 0.000 description 2
- 239000010439 graphite Substances 0.000 description 2
- 238000004898 kneading Methods 0.000 description 2
- 238000005096 rolling process Methods 0.000 description 2
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 description 1
- 229910012851 LiCoO 2 Inorganic materials 0.000 description 1
- 229910015643 LiMn 2 O 4 Inorganic materials 0.000 description 1
- 229910014689 LiMnO Inorganic materials 0.000 description 1
- 229910013290 LiNiO 2 Inorganic materials 0.000 description 1
- 229910013870 LiPF 6 Inorganic materials 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 229910010413 TiO 2 Inorganic materials 0.000 description 1
- 239000006230 acetylene black Substances 0.000 description 1
- 229910021383 artificial graphite Inorganic materials 0.000 description 1
- 150000004770 chalcogenides Chemical class 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000013329 compounding Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000006258 conductive agent Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- IEJIGPNLZYLLBP-UHFFFAOYSA-N dimethyl carbonate Chemical compound COC(=O)OC IEJIGPNLZYLLBP-UHFFFAOYSA-N 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000008151 electrolyte solution Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 150000002484 inorganic compounds Chemical class 0.000 description 1
- 229910010272 inorganic material Inorganic materials 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000012046 mixed solvent Substances 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 239000007774 positive electrode material Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Landscapes
- Secondary Cells (AREA)
- Battery Electrode And Active Subsutance (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、炭素粉末を負極材料と
するリチウム二次電池に係わり、特にサイクル特性の向
上を目的とした当該炭素粉末の結着に使用する結着剤の
改良に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lithium secondary battery using carbon powder as a negative electrode material, and more particularly to an improvement in a binder used for binding the carbon powder for the purpose of improving cycle characteristics.
【０００２】[0002]
【従来の技術及び発明が解決しようとする課題】近年、
リチウム二次電池の負極材料として、可撓性に優れるこ
と、モッシー状のリチウムが電析するおそれがないこと
などの理由から、黒鉛やコークスなどのリチウムを吸蔵
放出可能な炭素粉末（以下、単に「炭素粉末」と称する
ことがある。）が、従前の金属リチウム（箔や板）に代
わる負極材料として検討されている。2. Description of the Related Art In recent years,
As a negative electrode material for a lithium secondary battery, carbon powder capable of occluding and releasing lithium such as graphite and coke (hereinafter simply referred to as simply referred to as a graphite powder or coke) is used because of its excellent flexibility and absence of the possibility of depositing mossy lithium. "Carbon powder" may be referred to as a negative electrode material that replaces the conventional metallic lithium (foil or plate).
【０００３】この炭素粉末を使用した負極（以下、「炭
素負極」と称する。）は、結着剤と炭素粉末とを混練し
た後、集電体に圧延などにより接着して作製されてお
り、この場合の結着剤としては、主にポリフッ化ビニリ
デンが使用されている。A negative electrode using the carbon powder (hereinafter referred to as “carbon negative electrode”) is manufactured by kneading a binder and carbon powder and then bonding the kneaded material to a current collector by rolling or the like. As the binder in this case, polyvinylidene fluoride is mainly used.
【０００４】しかしながら、ポリフッ化ビニリデンは、
炭素粉末との密着性に優れるため炭素粉末同士を一体化
するための結着剤としては優れてはいるが、銅、アルミ
ニウムなどからなる集電体金属との密着性はさほど良く
ない。このため、ポリフッ化ビニリデンを結着剤として
使用した炭素負極においては、充放電サイクルを繰り返
すうちに炭素粉末の一部が集電体から剥離して電池容量
が漸減してしまうという問題があった。[0004] However, polyvinylidene fluoride is
Although excellent in adhesiveness with carbon powder, it is excellent as a binder for integrating carbon powders, but is not so good in adhesiveness with current collector metals such as copper and aluminum. For this reason, in the carbon anode using polyvinylidene fluoride as a binder, there was a problem that a part of the carbon powder was separated from the current collector and the battery capacity was gradually reduced while repeating the charge / discharge cycle. .
【０００５】本発明は、以上の事情に鑑みなされたもの
であって、その目的とするところは、炭素粉末の集電体
からの剥離が少ない、サイクル特性に優れたリチウム二
次電池を提供するにある。The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a lithium secondary battery which is excellent in cycle characteristics and in which carbon powder does not peel off from a current collector. It is in.
【０００６】[0006]
【課題を解決するための手段】上記目的を達成するため
の本発明に係るリチウム二次電池（以下、「本発明電
池」と称する。）は、リチウムを吸蔵放出可能な炭素粉
末と結着剤との混練物を集電体に接着してなる負極を備
えるリチウム二次電池であって、前記結着剤としてポリ
フッ化ビニリデン（ＰＶＤＦ）とポリメタクリレート
（ポリメタクリル酸エステル）との混合物が使用されて
いることを特徴とする。To achieve the above object, a lithium secondary battery according to the present invention (hereinafter referred to as "battery of the present invention") comprises a carbon powder capable of inserting and extracting lithium and a binder. Secondary battery comprising a negative electrode obtained by adhering a kneaded product of the above to a current collector, wherein a mixture of polyvinylidene fluoride (PVDF) and polymethacrylate (polymethacrylate) is used as the binder. It is characterized by having.
【０００７】本発明におけるリチウムを吸蔵放出可能な
炭素粉末としては、黒鉛粉末及びコークス粉末が例示さ
れる。リチウムを吸蔵放出可能な量（容量）が多い点で
黒鉛粉末が好ましい。黒鉛は、天然黒鉛であるか人造黒
鉛であるかを問われない。[0007] Examples of the carbon powder capable of inserting and extracting lithium in the present invention include graphite powder and coke powder. Graphite powder is preferred because it has a large amount (capacity) capable of inserting and extracting lithium. It does not matter whether the graphite is natural graphite or artificial graphite.
【０００８】本発明における負極は、炭素粉末を、ポリ
フッ化ビニリデンとポリメタクリレートとの混合物から
なる結着剤と混練した後、集電体上に圧延などの手段に
より接着して一体化することにより作製される。The negative electrode according to the present invention is obtained by kneading a carbon powder with a binder made of a mixture of polyvinylidene fluoride and polymethacrylate, and then bonding the powder to a current collector by rolling or other means to integrate the carbon powder. It is made.
【０００９】このように本発明において、結着剤として
ポリフッ化ビニリデンとポリメタクリレートとの混合物
を使用することとしたのは、従来のポリフッ化ビニリデ
ン単独からなる結着剤の欠点であった炭素粉末と集電体
金属との接着性の悪さを、集電体金属との密着性に優れ
たポリメタクリレートを配合することにより改良するた
めである。As described above, in the present invention, a mixture of polyvinylidene fluoride and polymethacrylate is used as the binder because the carbon powder which is a disadvantage of the conventional binder consisting of only polyvinylidene fluoride is used. The reason is that poor adhesion between the metal and the current collector metal is improved by blending polymethacrylate having excellent adhesion to the current collector metal.
【００１０】すなわち、本発明電池においては、炭素粉
末同士の結着は主としてポリフッ化ビニリデンにより行
われ、また一体化した炭素粉末の集電体金属との接着は
主としてポリメタクリレートにより行われる。That is, in the battery of the present invention, the binding between the carbon powders is mainly performed by polyvinylidene fluoride, and the bonding of the integrated carbon powder to the current collector metal is mainly performed by polymethacrylate.
【００１１】好適なポリメタクリレートとしては、ポリ
メチルメタクリレート（ＰＭＭＡ）、ポリエチルメタク
リレート（ＰＥＭＡ）などが挙げられるが、アルミニウ
ム、銅、ステンレス等の集電体金属との密着性に特に優
れるポリメチルメタクリレートが最適である。Examples of suitable polymethacrylates include polymethyl methacrylate (PMMA) and polyethyl methacrylate (PEMA). Polymethyl methacrylate which is particularly excellent in adhesion to a current collector metal such as aluminum, copper, and stainless steel. Is optimal.
【００１２】本発明における結着剤中へのポリメタクリ
レートの好適な配合比率は、１０〜９０重量％である。
１０重量％未満の場合は、炭素粉末の集電体金属との密
着性が不充分となり、また９０重量％を越えた場合は、
相対的にポリフッ化ビニリデンの配合比率が少なくなり
炭素粉末同士の結着が不充分となるので、ともに好まし
くない。The preferred compounding ratio of polymethacrylate in the binder in the present invention is 10 to 90% by weight.
When the amount is less than 10% by weight, the adhesion of the carbon powder to the current collector metal becomes insufficient, and when the amount exceeds 90% by weight,
Both are not preferred because the blending ratio of polyvinylidene fluoride is relatively small and the bonding between the carbon powders is insufficient.
【００１３】本発明は、結着剤としてポリフッ化ビニリ
デンを一種単独で使用していた従来の炭素電極が有する
集電体金属との密着性の不充分さ、すなわち炭素粉末の
集電体からの剥離のし易さを、ポリフッ化ビニリデンと
ポリメタクリレートとを併用することにより解消したも
のであり、したがって電池を構成する他の部材は、特に
制限されない。According to the present invention, the conventional carbon electrode, which uses polyvinylidene fluoride alone as a binder, has insufficient adhesion to the current collector metal of a conventional carbon electrode, that is, the carbon powder has a low The ease of peeling is eliminated by using polyvinylidene fluoride and polymethacrylate in combination, and other members constituting the battery are not particularly limited.
【００１４】たとえば正極材料としては、リチウムを吸
蔵放出可能な化合物であれば特に制限なく使用すること
ができ、無機化合物としては、ＴｉＯ2 、Ｖ2 Ｏ5 など
の所謂トンネル状の空孔を有する酸化物や、ＴｉＳ2 、
ＭｏＳ2 等の層状構造の金属カルコゲン化物が例示され
るが、組成式Ｌｉx ＭＯ2 又はＬｉy Ｍ2 Ｏ4 （ただ
し、Ｍは遷移元素、０≦ｘ≦１、０≦ｙ≦２）で表され
る複合酸化物が好ましく、その具体例としては、ＬｉＣ
ｏＯ2 、ＬｉＭｎＯ2 、ＬｉＮｉＯ2 、ＬｉＣｒＯ2 、
ＬｉＭｎ2 Ｏ4 が挙げられる。For example, as the positive electrode material, any compound capable of inserting and extracting lithium can be used without any particular limitation. As the inorganic compound, there are so-called tunnel-shaped holes such as TiO 2 and V 2 O 5. Oxides, TiS 2 ,
Examples of the metal chalcogenide having a layered structure such as MoS 2 include a composition formula Li x MO 2 or Li y M 2 O 4 (where M is a transition element, 0 ≦ x ≦ 1, 0 ≦ y ≦ 2). The composite oxide represented is preferable, and a specific example thereof is LiC
oO 2 , LiMnO 2 , LiNiO 2 , LiCrO 2 ,
LiMn 2 O 4 is exemplified.
【００１５】[0015]
【作用】本発明電池においては、結着剤としてポリフッ
化ビニリデンとポリメタクリレートとが併用されてお
り、炭素粉末同士の結着は主としてポリフッ化ビニリデ
ンにより、また炭素粉末と集電体金属との接着は主とし
てポリメタクリレートにより、それぞれ実現される。こ
のため、従来問題となっていた炭素粉末の集電体からの
剥離が起こりにくくなる。In the battery of the present invention, polyvinylidene fluoride and polymethacrylate are used in combination as binders, and the binding between carbon powders is mainly performed by polyvinylidene fluoride, and the adhesion between carbon powders and the current collector metal. Are mainly realized by polymethacrylate, respectively. For this reason, peeling of the carbon powder from the current collector, which has conventionally been a problem, is less likely to occur.
【００１６】[0016]
【実施例】以下、本発明を実施例に基づいてさらに詳細
に説明するが、本発明は下記実施例により何ら限定され
るものではなく、その要旨を変更しない範囲において適
宜変更して実施することが可能なものである。EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples, and may be carried out by appropriately changing the scope of the present invention. Is possible.
【００１７】（実施例１） 〔正極の作製〕ＬｉＣｏＯ2 と、導電剤としてのアセチ
レンブラックと、結着剤としてのＰＶＤＦ（ディスパー
ジョン）とを、重量比８５：１０：５で混合して正極合
剤を得た。この正極合剤を集電体としてのアルミニウム
箔に圧延し、２５０°Ｃで２時間真空下で加熱処理して
正極を作製した。(Example 1) [Preparation of positive electrode] LiCoO 2 , acetylene black as a conductive agent, and PVDF (dispersion) as a binder were mixed at a weight ratio of 85: 10: 5 to form a positive electrode. A mixture was obtained. This positive electrode mixture was rolled into an aluminum foil as a current collector, and heat-treated at 250 ° C. for 2 hours under vacuum to produce a positive electrode.
【００１８】〔負極の作製〕天然黒鉛粉末に、結着剤と
してのポリフッ化ビニリデンとポリメチルメタクリレー
ト（ディスパージョン）とを、重量比９５：２．５：
２．５の比率で混合して負極合剤を得た。この負極合剤
を集電体としての銅箔に圧延し、２５０°Ｃで２時間真
空下で加熱処理して負極を作製した。[Preparation of negative electrode] Polyvinylidene fluoride as a binder and polymethyl methacrylate (dispersion) were added to natural graphite powder in a weight ratio of 95: 2.5:
The mixture was mixed at a ratio of 2.5 to obtain a negative electrode mixture. This negative electrode mixture was rolled into a copper foil as a current collector, and heat-treated under vacuum at 250 ° C. for 2 hours to produce a negative electrode.
【００１９】〔電解液の調製〕エチレンカーボネートと
ジメチルカーボネートとの等体積混合溶媒に、溶質とし
てのＬｉＰＦ6 を１モル／リットル溶かして電解液を調
製した。[Preparation of Electrolyte] An electrolyte was prepared by dissolving 1 mol / liter of LiPF 6 as a solute in an equal volume mixed solvent of ethylene carbonate and dimethyl carbonate.
【００２０】〔リチウム二次電池の作製〕以上の正負両
極及び電解液を用いて円筒型の本発明電池ＢＡ１を作製
した（電池寸法：直径１４．２ｍｍ；長さ５０．０ｍ
ｍ）。なお、セパレータとしては、ポリプロピレン製の
微孔性薄膜（ポリプラスチックス社製、商品名「セルガ
ード３４０１」）を用いた。[Preparation of Lithium Secondary Battery] A cylindrical battery BA1 of the present invention was prepared using the positive and negative electrodes and the electrolyte described above (battery dimensions: 14.2 mm in diameter; 50.0 m in length).
m). As the separator, a microporous thin film made of polypropylene (manufactured by Polyplastics, trade name "Celgard 3401") was used.
【００２１】図１は作製した電池ＢＡ１の断面図であ
り、図示の電池ＢＡ１は、正極１及び負極２、これら両
電極を離隔するセパレータ３、正極リード４、負極リー
ド５、正極外部端子６、負極缶７などからなる。正極１
及び負極２は電解液が注入されたセパレータ３を介して
渦巻き状に巻き取られた状態で負極缶７内に収容されて
おり、正極１は正極リード４を介して正極外部端子６
に、また負極２は負極リード５を介して負極缶７に接続
され、電池ＢＡ１内部で生じた化学エネルギーを電気エ
ネルギーとして外部へ取り出し得るようになっている。FIG. 1 is a sectional view of the battery BA1 produced. The battery BA1 shown has a positive electrode 1 and a negative electrode 2, a separator 3 separating these electrodes, a positive electrode lead 4, a negative electrode lead 5, a positive electrode external terminal 6, It comprises a negative electrode can 7 and the like. Positive electrode 1
The negative electrode 2 is housed in a negative electrode can 7 in a state of being spirally wound through a separator 3 into which an electrolytic solution is injected, and the positive electrode 1 is connected to a positive electrode terminal 6 through a positive electrode lead 4.
In addition, the negative electrode 2 is connected to a negative electrode can 7 via a negative electrode lead 5, so that chemical energy generated inside the battery BA1 can be taken out as electric energy.
【００２２】（比較例１）天然黒鉛粉末に、結着剤とし
てのポリフッ化ビニリデン（ディスパージョン）を、重
量比９５：５の比率で混合して負極合剤を得た。この負
極合剤を集電体としての銅箔に圧延し、２５０°Ｃで２
時間真空下で加熱処理して負極を作製した。このように
して作製した負極を使用したこと以外は実施例１と同様
にして、比較電池ＢＣ１を作製した。Comparative Example 1 A negative electrode mixture was obtained by mixing natural graphite powder with polyvinylidene fluoride (dispersion) as a binder in a weight ratio of 95: 5. This negative electrode mixture was rolled into a copper foil as a current collector,
Heat treatment was performed under vacuum for a time to produce a negative electrode. A comparative battery BC1 was produced in the same manner as in Example 1 except that the thus produced negative electrode was used.
【００２３】（サイクル特性）本発明電池ＢＡ１及び比
較電池ＢＣ１について、充電電流２００ｍＡで充電終止
電圧４．１Ｖまで充電した後、放電電流２００ｍＡで放
電終止電圧３．０Ｖまで放電する工程を１サイクルとす
るサイクル試験を行い、各電池のサイクル特性を調べ
た。図２は、各電池のサイクル特性を、縦軸に電池容量
（ｍＡｈ）を、また横軸にサイクル数（回）をとって示
したグラフである。(Cycle Characteristics) A cycle of charging the battery BA1 of the present invention and the comparative battery BC1 to a charge end voltage of 4.1 V at a charge current of 200 mA and then discharging to a discharge end voltage of 3.0 V at a discharge current of 200 mA is defined as one cycle. A cycle test was performed to examine the cycle characteristics of each battery. FIG. 2 is a graph showing the cycle characteristics of each battery, with the vertical axis representing the battery capacity (mAh), and the horizontal axis representing the number of cycles (times).
【００２４】同図より、負極における黒鉛粉末の結着剤
としてポリフッ化ビニリデンとポリメチルメタクリレー
トとの混合物が使用されている本発明電池ＢＡ１では、
黒鉛粉末と集電体金属との接着性が良く剥離しにくいた
め、５００サイクル経過後においても電池容量が初期の
電池容量と同じく５００ｍＡｈであり全く低下していな
いのに対して、ポリフッ化ビニリデンを一種単独で使用
した比較電池ＢＣ１では、集電体金属からの黒鉛粉末の
剥離が起こるため、充放電サイクルを繰り返すうちに直
線的に電池容量が低下し、５００サイクル経過後におい
ては、３５０ｍＡｈにまで電池容量が低下してしまうこ
とが分かる。As shown in FIG. 1, in the battery BA1 of the present invention in which a mixture of polyvinylidene fluoride and polymethyl methacrylate is used as a binder for the graphite powder in the negative electrode,
Since the adhesion between the graphite powder and the current collector metal is good and it is difficult to peel off, the battery capacity is 500 mAh even after 500 cycles, which is the same as the initial battery capacity. In the comparative battery BC1 used alone, since the graphite powder was separated from the current collector metal, the battery capacity decreased linearly during repeated charge / discharge cycles, and was reduced to 350 mAh after 500 cycles. It can be seen that the battery capacity decreases.
【００２５】叙上の実施例ではポリフッ化ビニリデンと
併用するポリメタクリレートとしてポリメチルメタクリ
レートを使用する場合を例に挙げて説明したが、その他
ポリエチルメタクリレート（ＰＥＭＡ）等の他のポリメ
タクリレートを使用しても、同様に優れた結果が得られ
る。In the above embodiment, the case where polymethyl methacrylate is used as the polymethacrylate used in combination with polyvinylidene fluoride has been described as an example, but other polymethacrylates such as polyethyl methacrylate (PEMA) may be used. However, similarly excellent results can be obtained.
【００２６】また、叙上の実施例では本発明を円筒型電
池に適用する場合の具体例について説明したが、電池の
形状に特に制限はなく、本発明は扁平型、角型など、種
々の形状のリチウム二次電池に適用し得るものである。In the above embodiment, a specific example in which the present invention is applied to a cylindrical battery is described. However, the shape of the battery is not particularly limited, and the present invention is applicable to various types such as a flat type and a square type. The present invention can be applied to a lithium secondary battery having a shape.
【００２７】[0027]
【発明の効果】本発明電池は、負極材料たる炭素粉末が
集電体から剥離し難いため、これに起因したサイクル数
の経過に伴う電池容量の低下が殆どないなど、本発明は
優れた特有の効果を奏する。According to the battery of the present invention, the carbon powder as the negative electrode material is hardly peeled off from the current collector, so that the battery capacity hardly decreases with the lapse of the number of cycles due to this. Has the effect of
【図１】円筒型の本発明電池ＢＡ１の断面図である。FIG. 1 is a sectional view of a cylindrical battery BA1 of the present invention.
【図２】サイクル特性図である。FIG. 2 is a cycle characteristic diagram.
ＢＡ１ 円筒型の本発明電池 １ 正極 ２ 負極 ３ セパレータ BA1 Cylindrical battery of the present invention 1 Positive electrode 2 Negative electrode 3 Separator
───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.7，ＤＢ名) H01M 4/02 - 4/04 H01M 4/36 - 4/62 H01M 10/36 - 10/40 ──────────────────────────────────────────────────の Continued on the front page (58) Field surveyed (Int.Cl. 7 , DB name) H01M 4/02-4/04 H01M 4/36-4/62 H01M 10/36-10/40
Claims (3)
剤との混練物を集電体に接着してなる負極を備えるリチ
ウム二次電池であって、前記結着剤としてポリフッ化ビ
ニリデンとポリメタクリレートとの混合物が使用されて
いることを特徴とするリチウム二次電池。1. A lithium secondary battery comprising a negative electrode obtained by bonding a kneaded product of a carbon powder capable of inserting and extracting lithium and a binder to a current collector, wherein polyvinylidene fluoride is used as the binder. A lithium secondary battery characterized by using a mixture with polymethacrylate.
９０重量％含有するものである請求項１記載のリチウム
二次電池。2. The method according to claim 1, wherein the binder is polymethacrylate.
The lithium secondary battery according to claim 1, which contains 90% by weight.
クリレートである請求項２記載のリチウム二次電池。3. The lithium secondary battery according to claim 2, wherein said polymethacrylate is polymethyl methacrylate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22073492A JP3208183B2 (en) | 1992-07-27 | 1992-07-27 | Lithium secondary battery |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22073492A JP3208183B2 (en) | 1992-07-27 | 1992-07-27 | Lithium secondary battery |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0652861A JPH0652861A (en) | 1994-02-25 |
| JP3208183B2 true JP3208183B2 (en) | 2001-09-10 |
Family
ID=16755694
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP22073492A Expired - Fee Related JP3208183B2 (en) | 1992-07-27 | 1992-07-27 | Lithium secondary battery |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3208183B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011129528A (en) * | 1997-02-04 | 2011-06-30 | Mitsubishi Electric Corp | Method of manufacturing lithium ion secondary battery |
| JP4779885B2 (en) * | 1997-02-04 | 2011-09-28 | 三菱電機株式会社 | Lithium ion secondary battery |
| KR100449761B1 (en) * | 2002-05-18 | 2004-09-22 | 삼성에스디아이 주식회사 | Lithium secondary battery inhibiting decomposition of electrolytic solution and manufacturing method thereof |
-
1992
- 1992-07-27 JP JP22073492A patent/JP3208183B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0652861A (en) | 1994-02-25 |
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