JP4828683B2

JP4828683B2 - Method and apparatus for manufacturing battery electrode plate

Info

Publication number: JP4828683B2
Application number: JP2000205968A
Authority: JP
Inventors: 秀幸小林; 博文伊藤; 智秀六谷
Original assignee: Panasonic Corp; Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Corp; Panasonic Holdings Corp
Priority date: 2000-07-07
Filing date: 2000-07-07
Publication date: 2011-11-30
Anticipated expiration: 2020-07-07
Also published as: JP2002025541A

Description

【０００１】
【発明の属する技術分野】
本発明は、例えば金属箔やパンチングメタルなどの集電用芯材の表面にペースト状活物質を塗着して活物質層を形成してなる電池用電極板を製造する方法および装置に関するものである。
【０００２】
【従来の技術】
近年では、ＡＶ機器あるいはパソコンや携帯型通信機器などの電気機器のポータブル化やコードレス化が急速に促進されており、これら電気機器の駆動用電源としては、従来においてニッケルカドミウム電池やニッケル水素電池が主に用いられていたが、近年では、特に、急速充電が可能でエネルギ密度が高く、高い安全性を有するリチウムイオン二次電池に代表される非水電解液（有機溶媒系電解液）二次電池が主流になりつつある。この非水電解液二次電池の電極板は、一般に、金属箔やパンチングメタルなどの集電用芯材の表面に、溶液に溶解された結着剤中に正極活物質粉末または負極活物質粉末を分散させて混練したペースト状活物質を所定厚みに塗布して活物質層を形成し、この活物質層を乾燥して固化したのちに、所定の寸法に裁断して製造される。
【０００３】
従来では、集電用芯材にペースト状活物質を塗布するに際して、容器内に貯留されたペースト状活物質中に集電用芯材を通過させて引き上げ、ペースト状活物質が付着した集電用芯材を、容器の上方に配置したスリット板に通してペースト状活物質を所定厚みに付着する方法が一般に採用されている。上記ペースト状活物質の塗着厚みは、スリット板のスリットの間隙や芯材の引き上げ速度の他に、ペースト状活物質の粘度や密度に依存してばらつきが生じ易い。このように活物質の厚み（重量）にばらつきが生じると、電池としての品質の低下を招くことになる。
【０００４】
そのため、従来では、ペースト状活物質を乾燥させたのちに、任意の部分を一定の大きさに抜き取り、この抜き取ったサンプル片の重量を質量計により測定して、帯状電極板の単位面積当たりの重量を算出し、その算出結果に基づいて活物質層の厚みが所定値になるようにスリット板のスリットの間隙や芯材の引き上げ速度を制御していた。ところが、この重量測定方法では、帯状の芯材を長手方向に移送しながら連続的に重量を測定するといったことができないので、非能率的である上に測定精度が低い欠点がある。
【０００５】
そこで、近年では、帯状の芯材にペースト状活物質を塗着したペースト式帯状電極板に、放射線であるβ線を照射し、その透過放射線強度を測定し、その測定値と基準サンプルによって予め得られた基準値とを比較校正して誤差を演算し、その演算結果の電気信号を活物質塗着制御用スリットを構成する一対のブレードの間隔を調整する調整手段に伝達して常にスリットを調整し、活物質の塗着量を基準値に近づけるようにするペースト状活物質の塗着方法が提案されている（特開平8-96806 号公報参照）。
【０００６】
【発明が解決しようとする課題】
しかしながら、上記のベースト状活物質の塗着方法では、重量を連続的に測定できる利点がある反面、芯材の長手方向に沿った重量のばらつきが全く考慮されていないので、活物質層の重量の測定精度が低い課題がある。特に、単位面積当たりにおける芯材の重量の比率が高い電極板では、芯材の重量のばらつきの影響を受けて活物質の測定精度がさらに低下する。しかも、上記塗着方法では、活物質層における芯材の幅方向の重量を制御できないという別の欠点もあり、高精度な電池用電極板を歩留り良く製造することができない。
【０００７】
そこで、本発明は、上記従来の課題に鑑みてなされたもので、芯材に塗布されるペースト状活物質の重量を、芯材の重量のばらつきの影響を受けることなく連続的に測定して、芯材の長手方向および幅方向に重量のばらつきなくペースト状活物質を塗着することのできる電池用電極板の製造方法および製造装置を提供することを目的とするものである。
【０００８】
【課題を解決するための手段】
上記目的を達成するために、第１の発明に係る電池用電極板の製造方法は、帯状の集電用芯材を所定速度で連続的に移送しながら、前記集電用芯材の表面に、定量ポンプから供給されたペースト状活物質を活物質塗布機により塗布して活物質層を形成し、前記活物質層を乾燥させたのちの活物質塗着芯材に透過度の異なる複種類の放射線を照射して、透過度の高い放射線で前記活物質層塗着芯材の全体の重量を求め、透過度の低い放射線で芯材のみの重量を求め、全体の重量から芯材の重量を減算することによって前記活物質層のみの重量を測定したのちに、前記活物質層の重量データと予め定めた活物質層の重量に基づく基準データとの誤差を算出し、前記重量データに基づき前記誤差が設定範囲内になるように前記定量ポンプの回転数をフィードバック制御して前記活物質塗布機への前記ペースト状活物質の供給量を自動調整するようにしたことを特徴としている。
【０００９】
この電池用電極板の製造方法では、帯状の集電用芯材を連続的に移送しながら、その集電用芯材の表面にペースト状活物質を塗着して活物質層を形成し、この活物質層を乾燥して固化させたのちに、その活物質塗着芯材に複数の放射線を照射して、その各放射線の透過量に基づき連続的に重量を測定できる。しかも、重量測定は、透過度の異なる複種類の放射線を用いて行うので、透過度の高い放射線で芯材を含む活物質層全体の重量を求め、透過度の低い放射線で例えば芯材のみの重量を求めることが可能となり、全体の重量から芯材の重量を減算することによって活物質層のみの重量を算出することができる。したがって、芯材の長手方向の重量ばらつきの影響を排除して活物質層のみの重量を正確に得ることができる。さらに、活物質層の重量データと基準データとの誤差が設定範囲内になるように定量ポンプの回転数をフィードバック制御するので、ペースト状活物質の単位面積当たりの塗布重量を、一定速度で移送される集電用芯材の特に長手方向に対し一定になるよう自動的に調整することができる。
【００１０】
また、第２の発明に係る電池用電極板の製造方法は、帯状の集電用芯材を所定速度で連続的に移送しながら、前記集電用芯材の表面に、定量ポンプから供給されるペースト状活物質を、活物質塗布機における少なくとも前記集電用芯材の幅と同等の開口長さを有するスリットノズル部から吐出して塗布することにより活物質層を塗着形成し、前記活物質層を乾燥させたのちの活物質塗着芯材に透過度の異なる複種類の放射線を照射して、透過度の高い放射線で前記活物質層塗着芯材の全体の重量を求め、透過度の低い放射線で芯材のみの重量を求め、全体の重量から芯材の重量を減算することによって前記活物質層のみの重量を測定したのちに、前記活物質層の重量データと予め定めた前記活物質層の重量に基づく基準データとの誤差を算出し、前記重量データに基づき前記誤差が設定範囲内になるように前記スリットノズル部と前記集電用芯材との間隔をフィードバック制御するようにしたことを特徴としている。
【００１１】
この電池用電極板の製造方法では、第１の発明と同様に、各放射線の透過量に基づき連続的に重量を測定でき、芯材の長手方向の重量ばらつきの影響を排除して活物質層のみの重量を正確に得ることができる。さらに、活物質層の重量データと基準データとの誤差が設定範囲内になるようにスリットノズル部と集電用芯材との間隔をフィードバック制御するので、スリットノズル部から吐出されるペースト状活物質の単位面積当たりの塗布重量を、一定速度で移送される集電用芯材の特に幅方向に対し一定になるよう自動制御できる。
【００１２】
さらに、第３の発明に係る電池用電極板の製造方法は、帯状の集電用芯材を所定速度で連続的に移送しながら、前記集電用芯材の表面に、定量ポンプから供給されたペースト状活物質を、活物質塗布機における少なくとも前記集電用芯材の幅と同等の開口長さを有するスリットノズル部から吐出することにより活物質層を形成し、前記活物質層を乾燥させたのちの活物質塗着芯材に透過度の異なる複種類の放射線を照射して、透過度の高い放射線で前記活物質層塗着芯材の全体の重量を求め、透過度の低い放射線で芯材のみの重量を求め、全体の重量から芯材の重量を減算することによって前記活物質層のみの重量を測定したのちに、前記活物質層の重量データと予め定めた前記活物質層の重量に基づく基準データとの誤差を算出し、前記重量データに基づき前記誤差が設定範囲内になるように定量ポンプの回転数および前記スリットノズル部と前記集電用芯材との間隔をそれぞれフィードバック制御するようにしたことを特徴としている。
【００１３】
この電池用電極板の製造方法では、第１および第２の発明と同様に、各放射線の透過量に基づき連続的に重量を測定でき、芯材の長手方向の重量ばらつきの影響を排除して活物質層のみの重量を正確に得ることができる。それに加えて、活物質層の重量データと基準データとの誤差が設定範囲内になるように定量ポンプの回転数およびスリットノズル部の先端吐出口と集電用芯材との間隔をそれぞれフィードバック制御するので、ペースト状活物質の単位面積当たりの塗布重量を、一定速度で移送される集電用芯材の長手方向および幅方向に対して何れも一定になるよう自動制御することができる。
【００１４】
一方、本発明の電池用電極板の製造装置は、帯状の集電用芯材を所定速度で連続的に移送する移送手段と、少なくとも前記集電用芯材の幅と同等の開口長さを有するスリットノズル部からペースト状活物質を吐出して前記集電用芯材の表面に活物質層を塗着形成する活物質塗布機と、前記活物質塗布機を前記スリットノズル部と前記集電用芯材との間隔が変化する方向に移動する移動体と、前記活物質塗布機にペースト状活物質を供給する定量ポンプと、前記活物質塗布機を通過したあとの活物質塗着芯材における前記活物質層を乾燥する乾燥炉と、前記乾燥炉を通過した前記活物質塗着芯材に透過度の異なる複種類の放射線を照射して、透過度の高い放射線で前記活物質層塗着芯材の全体の重量を求め、透過度の低い放射線で芯材のみの重量を求め、全体の重量から芯材の重量を減算することによって前記活物質層のみの重量を測定する重量測定装置と、前記重量測定装置による前記活物質層の重量データと予め定めた前記活物質層の重量に基づく基準データとを比較演算してその誤差を算出したのちに、前記重量データに基づき前記誤差が設定範囲内になるように前記定量ポンプの回転数および前記移動体の位置をそれぞれフィードバック制御するコントローラとを備えて構成されていることを特徴としている。
【００１５】
この電池用電極板の製造装置では、第１ないし第３の発明に係る電池用電極板の製造方法のいずれを忠実に具現化して、製造方法の効果を確実に得ることができる。
【００１６】
上記発明の製造装置において、重量測定装置は、少なくともβ線とＸ線とを活物質塗着芯材に照射するよう構成されていることが好ましい。これにより、物質に対する透過度が極めて高いβ線の透過量に基づき活物質塗着芯材全体の重量を正確に求めることができ、透過度の低いＸ線の透過量に基づき芯材のみの重量を求めることができ、全体重量から芯材の重量を減算して活物質層のみの重量を高精度に算出することができる。
【００１７】
上記構成におけるβ線の線源はクリプトン85であることが好ましい。これにより、β線の活物質塗着芯材に対する透過性が良くなるので、単位面積当たりの重量の測定精度を高めることができる。
【００１８】
【発明の実施の形態】
以下、本発明の好ましい実施の形態について図面を参照しつつ詳細に説明する。図１は、本発明の電池用電極板の製造方法を具現化した製造装置を示す概略構成図である。例えば、帯状の金属箔からなる集電用芯材１は、巻き出し機２にコイル状に巻かれて、巻き取り機３の巻き取り力により巻き出し機２から繰り出されて一定速度で移送されながら一面に活物質層が形成され、最終的に巻き取り機３に再びコイル状に巻き取られる。この一面のみに活物質層が形成された活物質塗着芯材１８は、巻き取り機３から外して巻き出し機２に取り付けられたのちに、上述と同様にして他面にも活物質層が形成され、帯状電極板とされる。この帯状電極板は、所定寸法に裁断されることにより、所望の電池用電極板となる。
【００１９】
巻き出し機２から繰り出された集電用芯材１は、ガイドローラ４，７，８に案内されながら移送されて回転ドラム９に巻き付けられる。回転ドラム９の近接位置には活物質塗布装置１０が設置されており、この活物質塗布装置１０では、ホッパー１１内に充満されたペースト状活物質１２が定量ポンプ１３の駆動によって活物質塗布機１４に一定量ずつ供給される。活物質塗布機１４は、供給されたペースト状活物質１２を自体の先端のスリットノズル部１４ａから吐出して、回転ドラム９に巻き付けられた状態で移送される集電用芯材１の一面に層状に塗布する。これにより、集電用芯材１の表面には活物質層が形成される。なお、スリットノズル部１４ａの吐出口は、集電用芯材１の幅と同等の開口長さを有している。
【００２０】
一面に活物質層が形成された活物質塗着芯材１８は乾燥炉１７内に導入されて乾燥され、ペースト状活物質１２中の溶媒が加熱されて蒸発することにより、活物質層が確実に集電用芯材１に固定される。乾燥炉１７を出た活物質塗着芯材１８は、ガイドローラ１９，２０，２１に案内されて重量測定装置２２に導かれ、この重量測定装置２２で自体の重量を測定されたのち、ガイドローラ２３に案内されて巻き取り機３に巻き取られる。
【００２１】
図２は上記重量測定装置２２を示す概略構成図である。この重量測定装置２２は、上下一対の検出ヘッド２４，２７を備えており、下側検出ヘッド２７には、β線源２８とＸ線源２９とが内蔵されているとともに、上側検出ヘッド２４には、β線３２およびＸ線３３のそれぞれのレシーバである電離箱３０，３１が内蔵されている。β線源２８およびＸ線源２９から各々放射されたβ線３２およびＸ線３３は、活物質塗着芯材１８に照射され、且つ活物質塗着芯材１８を透過して対向する電離箱３０，３１に入射する。
【００２２】
上記の各電離箱３０，３１は、各々の下端開口部がそれぞれβ線３２およびＸ線３３を透過させる薄膜で閉ざされたボックスからなり、選択された適当なガスが内部に封入されているとともに中央電極と周囲電極とが同心円状に配設され、その中央電極と周囲電極との間に所定の直流電圧が印加された構成になっている。したがって、活物質塗着芯材１８をそれぞれ透過したβ線３２およびＸ線３３は、対応する電離箱３０，３１の下側の薄膜からボックス内に入り込み、その入射量に応じてガスをイオン化する。このイオンは中央と周囲の両電極に集められ、電離電流として出力端から個々のライン３４，３７を経て取り出され、図１のコントローラ３８に入力される。ここで、活物質塗着芯材１８に照射する２種の放射線のうちのβ線３２のβ線源２８としては、透過性に優れたものが好ましく、例えばクリプトン85が適している。
【００２３】
図１の電池用電極板の製造装置について再び説明する。各電離箱３０，３１からの透過β線および透過Ｘ線にそれぞれ比例した電離電流出力は、コントローラ３８に入力されて、このコントローラ３８に内蔵された演算処理部で演算処理されて活物質塗着芯材１８における活物質層のみの重量データに換算される。さらに、演算処理部では、算出した活物質層の重量データと予め定められた活物質層の重量に基づく基準データとを比較演算して、その誤差が算出される。
【００２４】
詳述すると、製造装置の稼働に先立って、活物質層の厚みが異なる複種類の活物質塗着芯材１８の基準サンプルを予め求めて、この基準サンプルにβ線３２およびＸ線３３をそれぞれ照射し、その透過β線および透過Ｘ線の各々の放射線強度と活物質塗着芯材１８の全体重量および集電用芯材１のみの重量との関係のデータを求め、このデータに基づいて、透過β線および透過Ｘ線の各々の強度、つまり２種の電離電流出力から活物質層のみの重量を算出する方程式を求めて、この方程式がコントローラ３８に記憶設定されている。
【００２５】
さらに詳述すると、クリプトン85から発せられるβ線３２は物質による質量吸収係数の差が小さいことから、その透過β線に比例した電離電流出力は、集電用芯材１を含む活物質塗着芯材１８全体の重量データに換算される。一方、透過Ｘ線に比例した電離電流出力は、Ｘ線３３の透過度がβ線３２よりも格段に小さいことから、集電用芯材１のみの重量データに換算される。すなわち、β線３２の透過前の強度および透過後の強度とその質量吸収係数とによって活物質塗着芯材１８全体の重量を算出する式が求められ、Ｘ線３３の透過前の強度および透過後の強度と質量吸収係数とによって集電用芯材１のみの重量を算出する式が求められるから、活物質塗着芯材１８全体の重量から集電用芯材１のみの重量を減算することによって活物質層のみの重量を求めることができる。コントローラ３８には、上述のようにして求められた活物質層のみの重量を算出するための方程式が記憶設定されている。
【００２６】
したがって、この電池用電極板の製造装置では、重量測定装置２２において、物質に対する透過度の異なる２種の放射線であるβ線３２とＸ線３３とを用いて一定速度で移送中の活物質塗着芯材１８の重量測定を連続的に行うことができるので、コントローラ３８において、活物質塗着芯材１８における集電用芯材１を除いた活物質層のみの重量データを算出でき、この算出した重量データと予め定めた活物質層の重量に基づく基準データとの誤差が演算により算出される。そのため、算出された誤差は、集電用芯材１の長さ方向の重量ばらつきの影響を受けない高精度なものとなる。コントローラ３８は、上述の重量データに基づき誤差が設定範囲内になるように活物質塗布装置１０を常時フィードバック制御する。この活物質塗布装置１０に対するフィードバック制御については後述する。
【００２７】
上記の重量測定装置２２による活物質層の測定精度の評価を行ったので、これについて説明する。負極活物質である黒鉛とブタジエンメタクリル酸スチレン共重合体ラテックスと結合剤を混合し、これをカルボキシメチルレルロースの水溶液に調整してなるペースト状活物質１２を、厚さ14μｍの銅箔からなる集電用芯材１に１塗工部当たり幅が468 ｍｍで長さが525 ｍｍの塗着範囲に約300 ｍにわたり塗着して、集電用芯材１に負極活物質層を形成し、この活物質層を乾燥したのちに、10列に裁断し、さらに所定の寸法に裁断して負極側電極板を作製し、この負極側電極板の負極活物質層の重量を上記実施の形態の重量測定装置２２で測定した。
【００２８】
一方、比較のために、従来のβ線のみによる重量測定装置で上記と同じ負極側電極板の負極活物質層の重量を測定した。その後に、上記負極側電極板の活物質層を削ぎ落として、集電用芯材１のみの重量を実際に測定し、先に測定した従来の重量測定装置による重量データから集電用芯材１の重量を減算して、比較例としての負極活物質層の重量を算出した。
【００２９】
上記実施の形態の重量測定装置２２で測定した負極活物質層の重量データと比較例の重量データとを比較したところ、比較例の重量データでは、誤差のばらつきが3.2 ％もあったのに対し、実施の形態の重量測定装置２２の重量データでは、誤差のばらつきが僅かに0.7 ％であった。これにより、実施の形態の重量測定装置２２は、β線３２とＸ線３３との透過度の異なる２種の放射線を用いたことにより、集電用芯材１の重量ばらつきの影響を排除して活物質層のみの重量を極めて正確に測定できることが確認できた。
【００３０】
図３は本発明の第１の実施の形態に係る電池用電極板の製造方法を具現化した製造装置の要部を示す概略構成図であり、同図において、図１と同一若しくは同等のものには同一の符号を付してある。この実施の形態では、コントローラ３８が重量測定装置２２で測定した重量データに基づいて、この重量データと予め定めた基準データとの誤差が設定範囲内になるように定量ポンプ１３の駆動モータ３９の回転数をフィードバック制御している。これにより、定量ポンプ１３によるペースト状活物質１２の活物質塗布機１４に対する供給量は重量データに基づきフィードバック制御されるので、ペースト状活物質１２の単位面積当たりの塗布重量は、一定速度で移送される集電用芯材１の特に長手方向に対し一定になるよう自動的に調整される。
【００３１】
図４（ａ）は本発明の第２の実施の形態に係る電池用電極板の製造方法を具現化した製造装置の要部を示す概略平面図、（ｂ）はその概略正面図であり、同部において、図１と同一若しくは同等のものには同一の符号を付してある。この実施の形態では、活物質塗布機１４を載置した支持台４０を、ガイドレール４１に沿って移動する移動体４２上に固定して、移動体４２の矢印方向の移動により、活物質塗布機１４におけるスリットノズル部１４ａの先端吐出口と回転ドラム９に巻き付けられながら移送される集電用芯材１との間隔ｄを調整できるようになっている。そして、コントローラ３８は、重量測定装置２２で測定した重量データに基づいて、この重量データと予め定めた基準データとの誤差が設定範囲内になるように移動体４２を移動させて上記間隔ｄをフィードバック制御する。これにより、スリットノズル部１４ａから吐出されるペースト状活物質１２の単位面積当たりの塗布重量は、一定速度で移送される集電用芯材１の特に幅方向に対し一定になるよう自動制御される。
【００３２】
図５は本発明の第３の実施の形態に係る電池用電極板の製造方法を具現化した製造装置の要部を示す構成図であり、同図において、図１、図３および図４と同一若しくは同等のものには同一の符号を付してある。この実施の形態では、ペースト状活物質１２の塗布重量を、第１および第２の実施の形態の各制御手段を併用してフィードバック制御している。すなわち、コントローラ３８は、重量測定装置２２で測定した重量データに基づいて、この重量データと予め定めた活物質層の重量に基づく基準データとの誤差が設定範囲内になるように定量ポンプ１３の駆動モータ３９の回転数およびスリットノズル部１４ａの先端吐出口と集電用芯材１との間隔ｄをそれぞれフィードバック制御している。これにより、ペースト状活物質１２の単位面積当たりの塗布重量は、一定速度で移送される集電用芯材１の長手方向および幅方向に対して何れも一定になるよう自動制御される。
【００３３】
つぎに、上記の第１ないし第３の実施の形態における各ペースト状活物質１２の塗布重量のフィードバック制御による評価を行ったので、これについて説明する。上述した負極側電極板を、第１ないし第３の各実施の形態のフィードバック制御を行いながらペースト状活物質１２の塗布重量を自動調整してそれぞれ製作し、これによって作製された３種の負極側電極板における活物質層の長手方向および幅方向のそれぞれの塗工重量のばらつきを測定した。一方、比較例として、重量の自動制御を行うことなくペースト状活物質を塗布して上述の負極側電極板を作製し、この負極側電極板における活物質層の長手方向および幅方向のそれぞれの塗工重量のばらつきを測定した。
【００３４】
先ず、長手方向の塗工重量のばらつきについては、比較例の負極側電極板が3.8 ％もあったのに対し、第１の実施の形態により作製した負極側電極板が、定量ポンプ１３によるペースト状活物質１２の供給量を自動制御したことによって1.4 ％と低くなり、第２の実施の形態により作製した負極側電極板が、比較例のものに対し低く、且つ第１の実施の形態のものよりも若干高い2.1 ％となり、第３の実施の形態により作製した負極側電極板が、定量ポンプ１３によるペースト状活物質１２の供給量の自動制御に加えてスリットノズル部１４ａの先端吐出口と集電用芯材１との間隔ｄを自動制御したことによって1.1 ％にまで低くなっている。
【００３５】
つぎに、幅方向の塗工重量のばらつきについては、比較例の負極側電極板が3.0 ％もあったのに対し、第１の実施の形態により作製した負極側電極板が、比較例のものに対し低い2.4 ％となり、第２の実施の形態により作製した負極側電極板が、スリットノズル部１４ａの先端吐出口と集電用芯材１との間隔ｄを自動制御したことによって第１の実施の形態のものよりも格段に低い1.0 ％となり、第３の実施の形態により作製した負極側電極板が定量ポンプ１３によるペースト状活物質１２の供給量の自動制御に加えてスリットノズル部１４ａの先端吐出口と集電用芯材１との間隔ｄを自動制御したことによって0.9 ％にまで低くなっている。これにより、本発明の製造方法により製造した電池用電極板は、ペースト状活物質１２の塗布重量を高精度に制御して、その測定結果に基づきペースト状活物質１２の塗布を自動制御することにより、長手方向および幅方向の何れについても塗布重量のばらつきを小さく抑えられることが確認できた。
【００３６】
【発明の効果】
以上のように本発明の電池用電極板の製造方法によれば、活物質塗着芯材の重量を、放射線の透過量に基づき連続的に測定でき、しかも、重量測定は、透過度の異なる複種類の放射線を用いて行うので、活物質層のみの重量を算出することができ、芯材の長手方向の重量ばらつきの影響を排除して活物質層のみの重量を正確に得ることができる。さらに、活物質層の重量データと基準データとの誤差が設定範囲内になるように定量ポンプの回転数をフィードバック制御するので、ペースト状活物質の単位面積当たりの塗布重量を、一定速度で移送される集電用芯材の特に長手方向に対し一定になるよう自動的に調整することができる。また、活物質層の重量データと基準データとの誤差が設定範囲内になるようにスリットノズル部と集電用芯材との間隔をフィードバック制御するので、スリットノズル部から吐出されるペースト状活物質の単位面積当たりの塗布重量を、一定速度で移送される集電用芯材の特に幅方向に対し一定になるよう自動制御できる。
【００３７】
また、本発明の電池用電極板の製造装置によれば、帯状の集電用芯材の移送手段と、ペースト状活物質を吐出して集電用芯材の表面に活物質層を塗着形成する活物質塗布機と、活物質塗布機の移動体と、活物質塗布機にペースト状活物質を供給する定量ポンプと、活物質層を乾燥する乾燥炉と、活物質層の重量を測定する重量測定装置と、定量ポンプの回転数および前記移動体の位置をそれぞれフィードバック制御するコントローラとを備えた構成としたので、本発明に係る電池用電極板の製造方法を忠実に具現化して、製造方法の効果を確実に得ることができる。
【図面の簡単な説明】
【図１】本発明の電池用電極板の製造方法を具現化した製造装置を示す概略構成図。
【図２】同上の製造装置における重量測定装置を示す構成図。
【図３】本発明の第１の実施の形態に係る電池用電極板の製造方法を具現化した製造装置の要部を示す構成図。
【図４】（ａ）は本発明の第２の実施の形態に係る電池用電極板の製造方法を具現化した製造装置の要部を示す概略平面図、（ｂ）はその概略正面図。
【図５】本発明の第３の実施の形態に係る電池用電極板の製造方法を具現化した製造装置の要部を示す構成図。
【符号の説明】
１集電用芯材
３巻き取り機（芯材移送手段）
１２ペースト状活物質
１３定量ポンプ
１４活物質塗布機
１４ａスリットノズル部
１８活物質塗着芯材
２２重量測定装置
３２ β線（放射線）
３３Ｘ線（放射線）
３８コントローラ
４２移動体
ｄスリットノズル部と集電用芯材との間隔[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and an apparatus for manufacturing a battery electrode plate in which an active material layer is formed by applying a paste-like active material on the surface of a current collecting core material such as a metal foil or a punching metal. is there.
[0002]
[Prior art]
In recent years, portable and cordless electronic devices such as AV devices, personal computers, and portable communication devices have been rapidly promoted. Conventionally, nickel cadmium batteries and nickel metal hydride batteries have been used as power sources for driving these electric devices. In recent years, non-aqueous electrolyte (organic solvent electrolyte) secondary, typically lithium ion secondary batteries, which can be rapidly charged, have high energy density, and have high safety. Batteries are becoming mainstream. The electrode plate of this non-aqueous electrolyte secondary battery is generally made of a positive electrode active material powder or a negative electrode active material powder in a binder dissolved in a solution on the surface of a current collecting core material such as metal foil or punching metal. A paste-like active material dispersed and kneaded is applied to a predetermined thickness to form an active material layer. The active material layer is dried and solidified, and then cut into a predetermined size.
[0003]
Conventionally, when applying a pasty active material to a current collecting core material, the current collecting core material is pulled up through the pasty active material stored in the container, and the pasted active material is attached. A method is generally adopted in which the core material is passed through a slit plate disposed above the container and the pasty active material is adhered to a predetermined thickness. The coating thickness of the paste-like active material tends to vary depending on the viscosity and density of the paste-like active material, in addition to the slit gap of the slit plate and the pulling speed of the core material. Thus, when the thickness (weight) of the active material varies, the quality of the battery is deteriorated.
[0004]
Therefore, conventionally, after drying the paste-like active material, an arbitrary portion is drawn out to a certain size, and the weight of the sample piece taken out is measured by a mass meter to obtain a per unit area of the strip electrode plate. The weight is calculated, and the slit gap of the slit plate and the pulling speed of the core material are controlled so that the thickness of the active material layer becomes a predetermined value based on the calculation result. However, this weight measuring method cannot be measured continuously while the strip-shaped core material is transported in the longitudinal direction, so that it is inefficient and has a drawback of low measurement accuracy.
[0005]
Therefore, in recent years, a paste-type band electrode plate in which a band-shaped core material is coated with a paste-like active material is irradiated with β-rays as radiation, and its transmitted radiation intensity is measured, and the measured value and reference sample are used in advance. Comparing and calibrating the obtained reference value to calculate the error, the electric signal of the calculation result is transmitted to the adjusting means for adjusting the distance between the pair of blades constituting the active material coating control slit, so that the slit is always opened. There has been proposed a method of applying a paste-like active material that is adjusted so that the amount of active material applied approaches a reference value (see JP-A-8-96806).
[0006]
[Problems to be solved by the invention]
However, the above-described method for applying a base-like active material has an advantage that the weight can be continuously measured, but the weight variation along the longitudinal direction of the core material is not considered at all. There is a problem of low measurement accuracy. In particular, in an electrode plate having a high ratio of the weight of the core material per unit area, the measurement accuracy of the active material is further lowered due to the influence of variations in the weight of the core material. Moreover, the coating method has another drawback that the weight in the width direction of the core material in the active material layer cannot be controlled, and a high-accuracy battery electrode plate cannot be manufactured with a high yield.
[0007]
Therefore, the present invention has been made in view of the above-described conventional problems, and continuously measures the weight of the paste-like active material applied to the core material without being affected by variations in the weight of the core material. An object of the present invention is to provide a battery electrode plate manufacturing method and a manufacturing apparatus capable of applying a paste-like active material in a longitudinal direction and a width direction of a core material without variation in weight.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, a method for manufacturing a battery electrode plate according to a first aspect of the present invention provides a method for producing a battery electrode plate on the surface of a current collecting core while continuously transferring a belt-shaped current collecting core at a predetermined speed. , Paste active material supplied from a metering pump by an active material coating machine to form an active material layer, and after drying the active material layer, the active material coated core material has different permeability Of radiation High transparency radiation To determine the total weight of the active material layer coated core material, Transparent By calculating the weight of only the core material with low radiation, and subtracting the weight of the core material from the total weight Active material layer only After measuring the weight of the active material layer, an error between the weight data of the active material layer and the reference data based on the weight of the active material layer determined in advance is calculated, and the error is within a set range based on the weight data. The feed rate of the pasty active material to the active material applicator is automatically adjusted by feedback control of the rotation speed of the metering pump.
[0009]
In this method of manufacturing a battery electrode plate, while continuously transferring a strip-shaped current collecting core material, a paste-like active material is applied to the surface of the current collecting core material to form an active material layer, After the active material layer is dried and solidified, the active material-coated core material can be irradiated with a plurality of radiations, and the weight can be continuously measured based on the amount of each radiation transmitted. In addition, since the weight measurement is performed using multiple types of radiation having different transmittances, the weight of the entire active material layer including the core material is obtained with radiation having high transmittance, and for example, only the core material is obtained with radiation having low transmittance. The weight can be obtained, and the weight of only the active material layer can be calculated by subtracting the weight of the core material from the total weight. Therefore, it is possible to accurately obtain the weight of only the active material layer by eliminating the influence of the weight variation in the longitudinal direction of the core material. In addition, since the rotation speed of the metering pump is feedback controlled so that the error between the weight data of the active material layer and the reference data is within the set range, the coating weight per unit area of the pasty active material is transferred at a constant speed. In particular, the current collecting core material can be automatically adjusted to be constant with respect to the longitudinal direction.
[0010]
Further, the battery electrode plate manufacturing method according to the second invention is supplied from the metering pump to the surface of the current collecting core while continuously feeding the belt-shaped current collecting core at a predetermined speed. The active material layer is applied and formed by discharging and applying a paste-like active material from a slit nozzle portion having an opening length equal to at least the width of the current collecting core in an active material applicator, After drying the active material layer, irradiate the active material coated core with multiple types of radiation with different transmittances. High transparency radiation To determine the total weight of the active material layer coated core material, Transparent By calculating the weight of only the core material with low radiation, and subtracting the weight of the core material from the total weight Active material layer only After measuring the weight of the active material layer, an error between the weight data of the active material layer and reference data based on the weight of the active material layer determined in advance is calculated, and the error is within a set range based on the weight data. Further, the distance between the slit nozzle part and the current collecting core material is feedback-controlled.
[0011]
In this battery electrode plate manufacturing method, as in the first aspect of the invention, the weight can be continuously measured based on the amount of transmission of each radiation, and the effect of weight variation in the longitudinal direction of the core material can be eliminated, and the active material layer Only the weight can be obtained accurately. Furthermore, since the distance between the slit nozzle part and the current collecting core is feedback controlled so that the error between the weight data of the active material layer and the reference data is within the set range, the paste-like active material discharged from the slit nozzle part is controlled. The coating weight per unit area of the substance can be automatically controlled so as to be constant particularly in the width direction of the current collecting core material transferred at a constant speed.
[0012]
Further, the battery electrode plate manufacturing method according to the third invention is supplied from the metering pump to the surface of the current collecting core while continuously feeding the belt-shaped current collecting core at a predetermined speed. The active material layer is formed by discharging the paste-like active material from a slit nozzle portion having an opening length equal to at least the width of the current collecting core in the active material coating machine, and drying the active material layer After irradiating the active material coated core material with multiple types of radiation with different transmittance, High transparency radiation To determine the total weight of the active material layer coated core material, Transparent By calculating the weight of only the core material with low radiation, and subtracting the weight of the core material from the total weight Active material layer only After measuring the weight of the active material layer, an error between the weight data of the active material layer and reference data based on the weight of the active material layer determined in advance is calculated, and the error is within a set range based on the weight data. Further, the rotational speed of the metering pump and the interval between the slit nozzle part and the current collecting core material are respectively feedback controlled.
[0013]
In this battery electrode plate manufacturing method, as in the first and second inventions, the weight can be continuously measured based on the amount of transmitted radiation, and the influence of the weight variation in the longitudinal direction of the core material is eliminated. The weight of only the active material layer can be obtained accurately. In addition, feedback control of the rotation speed of the metering pump and the interval between the tip discharge port of the slit nozzle and the current collecting core so that the error between the weight data of the active material layer and the reference data is within the set range. Therefore, the application weight per unit area of the paste-like active material can be automatically controlled so as to be constant with respect to the longitudinal direction and the width direction of the current collecting core material transferred at a constant speed.
[0014]
On the other hand, the battery electrode plate manufacturing apparatus of the present invention has a transfer means for continuously transferring a strip-shaped current collecting core material at a predetermined speed, and at least an opening length equivalent to the width of the current collecting core material. An active material applicator that discharges a paste-like active material from a slit nozzle portion and has an active material layer applied to the surface of the current collecting core; and the active material applicator includes the slit nozzle portion and the current collector. A moving body that moves in a direction in which the interval with the core material changes, a metering pump that supplies a paste-like active material to the active material applicator, and an active material-coated core material after passing through the active material applicator A drying oven for drying the active material layer, and the active material-coated core material that has passed through the drying oven is irradiated with a plurality of types of radiation having different transmittances, High transparency radiation To determine the total weight of the active material layer coated core material, Transparent By calculating the weight of only the core material with low radiation, and subtracting the weight of the core material from the total weight Active material layer only A weight measuring device for measuring the weight of the active material layer, the weight data of the active material layer by the weight measuring device and reference data based on the weight of the active material layer determined in advance, and calculating the error, And a controller that performs feedback control on the number of revolutions of the metering pump and the position of the moving body so that the error falls within a set range based on the weight data.
[0015]
In this battery electrode plate manufacturing apparatus, any of the battery electrode plate manufacturing methods according to the first to third aspects of the present invention can be faithfully realized, and the effects of the manufacturing method can be reliably obtained.
[0016]
In the manufacturing apparatus of the above invention, the weight measuring device is preferably configured to irradiate at least β rays and X rays to the active material-coated core material. This makes it possible to accurately determine the weight of the active material-coated core material based on the amount of β-ray transmission with a very high transmittance to the substance, and the weight of the core material alone based on the amount of X-ray transmission with a low transmittance. The weight of only the active material layer can be calculated with high accuracy by subtracting the weight of the core material from the total weight.
[0017]
The β-ray source in the above configuration is preferably krypton 85. Thereby, since the permeability | transmittance with respect to the active material coating core material of a beta ray becomes good, the measurement precision of the weight per unit area can be improved.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a manufacturing apparatus that embodies the method for manufacturing a battery electrode plate of the present invention. For example, the current collecting core 1 made of a strip-shaped metal foil is wound around the unwinder 2 in a coil shape, and is unwound from the unwinder 2 by the winding force of the winder 3 and transferred at a constant speed. On the other hand, an active material layer is formed on one surface, and finally wound around the winder 3 again in a coil shape. The active material coated core material 18 in which the active material layer is formed only on one surface is detached from the winder 3 and attached to the unwinder 2, and then the active material layer on the other surface in the same manner as described above. Is formed into a strip electrode plate. This strip-shaped electrode plate is cut into a predetermined size, thereby forming a desired battery electrode plate.
[0019]
The current collecting core 1 fed from the unwinder 2 is transferred while being guided by the guide rollers 4, 7, 8 and wound around the rotating drum 9. An active material application device 10 is installed in the vicinity of the rotary drum 9. In this active material application device 10, the paste-like active material 12 filled in the hopper 11 is driven by an active material application machine by driving a metering pump 13. 14 is supplied in a constant amount. The active material applicator 14 discharges the supplied paste-like active material 12 from the slit nozzle portion 14 a at the tip of the active material applicator 14, and is transferred to one surface of the current collecting core 1 that is transported while being wound around the rotary drum 9. Apply in layers. Thereby, an active material layer is formed on the surface of the current collecting core 1. The discharge port of the slit nozzle portion 14 a has an opening length equivalent to the width of the current collecting core material 1.
[0020]
The active material-coated core material 18 having an active material layer formed on one side is introduced into a drying furnace 17 and dried, and the solvent in the paste-like active material 12 is heated and evaporated, so that the active material layer is reliably formed. To the current collecting core 1. The active material-coated core material 18 exiting the drying furnace 17 is guided by guide rollers 19, 20, 21 and guided to a weight measuring device 22, and its weight is measured by the weight measuring device 22. It is guided by the roller 23 and taken up by the winder 3.
[0021]
FIG. 2 is a schematic configuration diagram showing the weight measuring device 22. The weight measuring device 22 includes a pair of upper and lower detection heads 24, 27. The lower detection head 27 includes a β-ray source 28 and an X-ray source 29, and the upper detection head 24 includes Includes ion chambers 30 and 31 which are receivers of β rays 32 and X rays 33, respectively. β-rays 32 and X-rays 33 radiated from the β-ray source 28 and the X-ray source 29 irradiate the active material-coated core material 18 and pass through the active material-coated core material 18 to face each other. 30 and 31 are incident.
[0022]
Each of the ionization chambers 30 and 31 includes a box whose lower end opening is closed with a thin film that transmits β-rays 32 and X-rays 33, respectively, and an appropriate gas selected is sealed inside. The central electrode and the peripheral electrode are concentrically arranged, and a predetermined DC voltage is applied between the central electrode and the peripheral electrode. Therefore, the β-ray 32 and the X-ray 33 that have passed through the active material-coated core material 18 enter the box from the thin film below the corresponding ionization chambers 30 and 31 and ionize the gas according to the incident amount. . These ions are collected at both the center and surrounding electrodes, taken out from the output end as an ionization current through individual lines 34 and 37, and input to the controller 38 in FIG. Here, as the β-ray source 28 of the β-ray 32 of the two types of radiation irradiated to the active material-coated core material 18, one having excellent permeability is preferable, for example, krypton 85 is suitable.
[0023]
The battery electrode plate manufacturing apparatus of FIG. 1 will be described again. Ionization current outputs proportional to the transmitted β-rays and transmitted X-rays from the ionization chambers 30 and 31 are input to the controller 38 and processed by an arithmetic processing unit built in the controller 38 to apply the active material. It is converted into weight data of only the active material layer in the core material 18. Further, the arithmetic processing unit compares the calculated weight data of the active material layer with reference data based on a predetermined weight of the active material layer, and calculates the error.
[0024]
Specifically, prior to the operation of the manufacturing apparatus, reference samples of the active material coated core material 18 having different active material layer thicknesses are obtained in advance, and β-rays 32 and X-rays 33 are respectively added to the reference samples. Irradiation is performed to obtain data on the relationship between the radiation intensity of each of the transmitted β-rays and transmitted X-rays and the total weight of the active material-coated core material 18 and the weight of the current collecting core material 1 alone. Then, an equation for calculating the intensity of each of the transmitted β-rays and the transmitted X-rays, that is, the weight of only the active material layer from the two types of ionization current outputs, is obtained and stored in the controller 38.
[0025]
More specifically, since the β-ray 32 emitted from the krypton 85 has a small difference in mass absorption coefficient depending on the substance, the ionizing current output proportional to the transmitted β-ray is applied to the active material containing the current collecting core 1. It is converted into weight data of the entire core material 18. On the other hand, the ionization current output proportional to the transmitted X-ray is converted into weight data of only the current collecting core 1 because the transmittance of the X-ray 33 is much smaller than that of the β-ray 32. That is, an equation for calculating the weight of the active material-coated core material 18 as a whole is calculated based on the intensity before and after transmission of the β-ray 32 and its mass absorption coefficient, and the intensity and transmission before transmission of the X-ray 33. Since the formula for calculating the weight of only the current collecting core material 1 is obtained from the subsequent strength and the mass absorption coefficient, the weight of only the current collecting core material 1 is subtracted from the weight of the active material coated core material 18 as a whole. Thus, the weight of only the active material layer can be obtained. The controller 38 stores and sets an equation for calculating the weight of only the active material layer obtained as described above.
[0026]
Therefore, in this battery electrode plate manufacturing apparatus, the active material coating being transferred at a constant speed using the β-ray 32 and the X-ray 33 which are two types of radiation having different transmittances to the substance in the weight measuring device 22. Since the weight measurement of the core material 18 can be continuously performed, the controller 38 can calculate the weight data of only the active material layer excluding the current collecting core material 1 in the active material coating core material 18. An error between the calculated weight data and reference data based on a predetermined weight of the active material layer is calculated. Therefore, the calculated error is highly accurate without being affected by the weight variation in the length direction of the current collecting core material 1. The controller 38 always feedback-controls the active material coating apparatus 10 so that the error is within the set range based on the weight data. Feedback control for the active material coating apparatus 10 will be described later.
[0027]
Since the evaluation of the measurement accuracy of the active material layer by the weight measuring device 22 was performed, this will be described. A paste active material 12 prepared by mixing graphite, a butadiene methacrylic acid styrene copolymer latex, and a binder, which are negative electrode active materials, and adjusting this into an aqueous solution of carboxymethyl allerulose is made of a copper foil having a thickness of 14 μm. The current collector core material 1 is applied over a coating area of 468 mm in width and 525 mm in length per coating part over approximately 300 m to form a negative electrode active material layer on the current collector core material 1. Then, after drying this active material layer, it is cut into 10 rows, and further cut into a predetermined size to produce a negative electrode side electrode plate, and the weight of the negative electrode active material layer of this negative electrode side electrode plate is The weight measuring device 22 was used.
[0028]
On the other hand, for comparison, the weight of the negative electrode active material layer of the same negative electrode plate as described above was measured with a conventional weight measuring apparatus using only β rays. Thereafter, the active material layer of the negative electrode plate is scraped off, and the weight of the current collecting core 1 alone is actually measured, and the current collecting core is obtained from the weight data measured by the conventional weight measuring device previously measured. The weight of 1 was subtracted to calculate the weight of the negative electrode active material layer as a comparative example.
[0029]
When comparing the weight data of the negative electrode active material layer measured by the weight measuring device 22 of the above embodiment and the weight data of the comparative example, the weight data of the comparative example showed an error variation of 3.2%. In the weight data of the weight measuring device 22 of the embodiment, the error variation was only 0.7%. As a result, the weight measuring device 22 of the embodiment eliminates the influence of the weight variation of the current collecting core 1 by using two types of radiation having different transmittances of the β-ray 32 and the X-ray 33. It was confirmed that the weight of the active material layer alone could be measured very accurately.
[0030]
FIG. 3 is a schematic configuration diagram showing a main part of a manufacturing apparatus that embodies the manufacturing method of the battery electrode plate according to the first embodiment of the present invention, in which the same or equivalent parts as FIG. Are denoted by the same reference numerals. In this embodiment, based on the weight data measured by the weight measuring device 22 by the controller 38, the drive motor 39 of the metering pump 13 is controlled so that the error between the weight data and the predetermined reference data is within the set range. The rotational speed is feedback controlled. As a result, the feed amount of the pasty active material 12 to the active material applicator 14 by the metering pump 13 is feedback-controlled based on the weight data, so that the coating weight per unit area of the pasty active material 12 is transferred at a constant speed. The current collecting core 1 is automatically adjusted to be constant particularly in the longitudinal direction.
[0031]
FIG. 4 (a) is a schematic plan view showing the main part of a manufacturing apparatus that embodies the method for manufacturing a battery electrode plate according to the second embodiment of the present invention, and FIG. 4 (b) is a schematic front view thereof. In the same part, the same or equivalent parts as in FIG. In this embodiment, the support base 40 on which the active material applicator 14 is placed is fixed on the moving body 42 that moves along the guide rail 41, and the moving material 42 moves in the direction of the arrow to apply the active material. The distance d between the tip discharge port of the slit nozzle portion 14a of the machine 14 and the current collecting core material 1 that is transferred while being wound around the rotary drum 9 can be adjusted. Then, the controller 38 moves the moving body 42 based on the weight data measured by the weight measuring device 22 so that the error between the weight data and the predetermined reference data is within the set range, thereby setting the interval d. Feedback control. Thereby, the coating weight per unit area of the paste-like active material 12 discharged from the slit nozzle portion 14a is automatically controlled so as to be constant particularly in the width direction of the current collecting core material 1 transferred at a constant speed. The
[0032]
FIG. 5 is a block diagram showing a main part of a manufacturing apparatus that embodies a manufacturing method of a battery electrode plate according to a third embodiment of the present invention, in which FIG. 1, FIG. 3, and FIG. The same or equivalent parts are denoted by the same reference numerals. In this embodiment, the application weight of the paste-like active material 12 is feedback-controlled using the control means of the first and second embodiments together. That is, based on the weight data measured by the weight measuring device 22, the controller 38 controls the metering pump 13 so that the error between the weight data and the reference data based on the weight of the predetermined active material layer is within the set range. The rotational speed of the drive motor 39 and the distance d between the tip discharge port of the slit nozzle portion 14a and the current collecting core material 1 are feedback-controlled. Thereby, the coating weight per unit area of the paste-like active material 12 is automatically controlled so as to be constant in both the longitudinal direction and the width direction of the current collecting core material 1 transferred at a constant speed.
[0033]
Next, the evaluation by feedback control of the application weight of each pasty active material 12 in the first to third embodiments will be described. The negative electrode plate described above is manufactured by automatically adjusting the application weight of the paste-like active material 12 while performing feedback control of each of the first to third embodiments, and three types of negative electrodes manufactured thereby. Variations in the coating weight in the longitudinal direction and width direction of the active material layer in the side electrode plate were measured. On the other hand, as a comparative example, the above-described negative electrode plate was prepared by applying a paste-like active material without automatically controlling the weight, and the active material layer in the negative electrode plate in the longitudinal direction and the width direction of the negative electrode plate, respectively. The variation in coating weight was measured.
[0034]
First, regarding the dispersion in the coating weight in the longitudinal direction, the negative electrode plate of the comparative example was as much as 3.8%, whereas the negative electrode plate produced according to the first embodiment was a paste by the metering pump 13. The supply amount of the active material 12 is automatically controlled to be as low as 1.4%, the negative electrode plate produced according to the second embodiment is lower than that of the comparative example, and the first embodiment The negative electrode plate produced according to the third embodiment is slightly higher than that of 2.1%, and in addition to the automatic control of the supply amount of the paste-like active material 12 by the metering pump 13, the tip discharge port of the slit nozzle portion 14a And 1.1% due to automatic control of the distance d between the current collector core 1 and the current collecting core 1.
[0035]
Next, regarding the variation in the coating weight in the width direction, the negative electrode plate of the comparative example was 3.0%, whereas the negative electrode plate prepared according to the first embodiment was of the comparative example. The negative electrode plate produced according to the second embodiment automatically controlled the distance d between the tip discharge port of the slit nozzle portion 14a and the current collecting core material 1 because of the low 2.4%. The negative electrode plate produced by the third embodiment is 1.0% much lower than that of the embodiment, and the slit nozzle portion 14a is added to the automatic control of the supply amount of the paste-like active material 12 by the metering pump 13. The distance d between the tip discharge port and the current collecting core 1 is automatically controlled, so that it is as low as 0.9%. Thereby, the battery electrode plate manufactured by the manufacturing method of the present invention controls the application weight of the paste-like active material 12 with high accuracy, and automatically controls the application of the paste-like active material 12 based on the measurement result. Thus, it was confirmed that the variation in coating weight can be kept small in both the longitudinal direction and the width direction.
[0036]
【The invention's effect】
As described above, according to the battery electrode plate manufacturing method of the present invention, the weight of the active material-coated core material can be continuously measured based on the amount of transmitted radiation, and the weight measurement has different transmittances. Since multiple types of radiation are used, the weight of only the active material layer can be calculated, and the influence of the weight variation in the longitudinal direction of the core material can be eliminated to accurately obtain the weight of only the active material layer. . In addition, since the rotation speed of the metering pump is feedback controlled so that the error between the weight data of the active material layer and the reference data is within the set range, the coating weight per unit area of the pasty active material is transferred at a constant speed. In particular, the current collecting core material can be automatically adjusted to be constant with respect to the longitudinal direction. In addition, since the distance between the slit nozzle part and the current collecting core is feedback controlled so that the error between the weight data of the active material layer and the reference data is within the set range, the paste-like active material discharged from the slit nozzle part is controlled. The coating weight per unit area of the substance can be automatically controlled so as to be constant particularly in the width direction of the current collecting core material transferred at a constant speed.
[0037]
In addition, according to the battery electrode plate manufacturing apparatus of the present invention, the belt-shaped current collecting core material transferring means and the paste-like active material are discharged to apply the active material layer to the surface of the current collecting core material. Measures the weight of the active material layer, the active material applicator to be formed, the moving body of the active material applicator, the metering pump that supplies the active material applicator to the paste active material, the drying furnace that dries the active material layer, and the active material layer And a controller that feedback controls the number of revolutions of the metering pump and the position of the moving body, so that the method for manufacturing the battery electrode plate according to the present invention is faithfully realized, The effect of the manufacturing method can be obtained with certainty.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing a manufacturing apparatus embodying a method for manufacturing a battery electrode plate according to the present invention.
FIG. 2 is a configuration diagram showing a weight measuring device in the manufacturing apparatus.
FIG. 3 is a configuration diagram showing a main part of a manufacturing apparatus that embodies the manufacturing method of the battery electrode plate according to the first embodiment of the invention.
4A is a schematic plan view showing a main part of a manufacturing apparatus that embodies a method for manufacturing a battery electrode plate according to a second embodiment of the present invention, and FIG. 4B is a schematic front view thereof.
FIG. 5 is a configuration diagram showing a main part of a manufacturing apparatus that embodies a manufacturing method of a battery electrode plate according to a third embodiment of the present invention.
[Explanation of symbols]
1 Core material for current collection
3 Winder (core material transfer means)
12 Paste-like active material
13 Metering pump
14 Active material applicator
14a Slit nozzle part
18 Active material coated core material
22 Weight measuring device
32 β-ray (radiation)
33 X-rays (radiation)
38 controller
42 Mobile
d Distance between slit nozzle and current collecting core

Claims

While continuously feeding the belt-shaped current collecting core material at a predetermined speed, the active material layer is formed by applying the paste-like active material supplied from the metering pump to the surface of the current collecting core material by an active material coating machine. Form the
After the active material layer is dried, the active material coated core material is irradiated with multiple types of radiation having different transmittances,
The total weight of the core material coated with the active material layer is determined with radiation having a high transmittance, the weight of only the core material is determined with radiation with a low transmittance , and the weight of the core material is subtracted from the total weight. After measuring the weight of only the material layer, calculate the error between the weight data of the active material layer and the reference data based on the weight of the active material layer determined in advance,
The feed rate of the pasty active material to the active material applicator is automatically adjusted by feedback control of the rotation speed of the metering pump so that the error falls within a set range based on the weight data. A method for producing a battery electrode plate.

While continuously feeding the belt-shaped current collecting core material at a predetermined speed, the paste-like active material supplied from the metering pump is applied to the surface of the current collecting core material at least in the active material coating machine. The active material layer is applied and formed by discharging and applying from a slit nozzle portion having an opening length equivalent to the width of the core material,
After the active material layer is dried, the active material-coated core material is irradiated with a plurality of types of radiation having different transmittances , and the total weight of the active material layer-coated core material is determined with radiation having a high transmittance. , calculated on the weight of only the core material with a low permeability radiation, after which weighed only the active material layer by subtracting the weight of the core material from the total weight, in advance and the weight data of the active material layer Calculate the error from the reference data based on the weight of the defined active material layer,
A method for manufacturing an electrode plate for a battery, wherein an interval between the slit nozzle portion and the core material for current collection is feedback-controlled so that the error falls within a set range based on the weight data.

While continuously transporting the belt-shaped current collecting core material at a predetermined speed, the paste-like active material supplied from the metering pump is applied to the surface of the current collecting core material at least in the active material coating machine. An active material layer is formed by discharging from a slit nozzle portion having an opening length equivalent to the width of the core material,
After the active material layer is dried, the active material-coated core material is irradiated with a plurality of types of radiation having different transmittances , and the total weight of the active material layer-coated core material is determined with radiation having a high transmittance. , calculated on the weight of only the core material with a low permeability radiation, after which weighed only the active material layer by subtracting the weight of the core material from the total weight, in advance and the weight data of the active material layer Calculate the error from the reference data based on the weight of the defined active material layer,
The battery is characterized in that the number of revolutions of the metering pump and the interval between the slit nozzle part and the current collecting core are feedback controlled so that the error falls within a set range based on the weight data. Manufacturing method of electrode plate.

Transfer means for continuously transferring the belt-shaped current collecting core material at a predetermined speed;
An active material applicator that discharges a paste-like active material from a slit nozzle portion having an opening length equal to at least the width of the current collecting core material to apply and form an active material layer on the surface of the current collecting core material When,
A moving body that moves the active material applicator in a direction in which an interval between the slit nozzle portion and the current collecting core changes;
A metering pump for supplying a pasty active material to the active material applicator;
A drying furnace for drying the active material layer in the active material coating core material after passing through the active material coating machine;
The drying furnace double type of radiation having different permeability to the active substance-application core material has passed through the irradiated, calculated on the total weight of the active material layer the coating core material with high permeability radiation, permeability A weight measuring device for measuring the weight of only the active material layer by subtracting the weight of the core material from the total weight, obtaining the weight of the core material only with low radiation ,
After calculating the error by comparing the weight data of the active material layer by the weight measuring device and the reference data based on the weight of the active material layer determined in advance, the error is within a set range based on the weight data An apparatus for manufacturing a battery electrode plate, comprising: a controller for feedback-controlling the rotational speed of the metering pump and the position of the moving body so as to be inside.

The battery electrode plate manufacturing apparatus according to claim 4, wherein the weight measuring device is configured to irradiate at least β rays and X rays to the active material-coated core material.

The battery electrode plate manufacturing apparatus according to claim 5, wherein the β-ray source is krypton 85.