JP4298245B2

JP4298245B2 - Winding battery and manufacturing method thereof

Info

Publication number: JP4298245B2
Application number: JP2002262382A
Authority: JP
Inventors: 香津雄堤; 和也西村
Original assignee: Kawasaki Jukogyo KK
Current assignee: Kawasaki Motors Ltd
Priority date: 2002-09-09
Filing date: 2002-09-09
Publication date: 2009-07-15
Anticipated expiration: 2022-09-09
Also published as: JP2004103350A

Description

【０００１】
【発明の属する技術分野】
本発明は、正極活物質シート、セパレータおよび負極活物質シートを重ね合わせて捲回してなる電極体を用いた巻き電池およびその製造方法に関する。
【０００２】
【従来の技術】
ニッケル水素電池などに代表される円筒状の巻き電池は、正極活物質（水酸化ニッケルなど）を含む正極活物質シートと、負極活物質（水素吸蔵合金など）を含む負極活物質シートとが、両シート間を電気絶縁し、その中に含まれる電解液を介してイオンを伝導させる板状のセパレータを介して渦巻き状に捲回された電極体を備える。該電極体の最外周層は負極活物質シートになるように構成されており、負極外部端子を兼ねる一端に開口を有する有底筒状の電池容器に収納されている。該電池容器の開口は、その中央部が突設した板状の正極外部端子で覆われており、これによって、正極外部端子が電池容器の一部を構成している（例えば、特許文献１参照）。また、正極外部端子と電極体の正極活物質シートとは、ニッケルなど導電性のタブを介してそれぞれ溶接されている（例えば、特許文献２参照）。
【０００３】
【特許文献１】
特開２００２−８７１０号公報（第１頁、図１）
【特許文献２】
特開平５−２３４６１６号公報（第３頁、図１）
【０００４】
【発明が解決しようとする課題】
しかしながら、上記の巻き電池の構造では、電気が流れる正極側の経路に溶接部を２箇所有する。該溶接部の電気抵抗のため、巻き電池を高出力放電する場合に巻き電池の両端間の電圧が低下し、巻き電池の性能を十分に確保することができない。また、溶接部があるために巻き電池の製造時間が多く掛かり、製造コストも多く掛かる。
【０００５】
本発明は、上記の問題点に鑑みてなされたものであり、電極体の正極活物質シートを正極外部端子に、電極体の負極活物質シートを負極外部端子にそれぞれ溶接せず当接により電気的に接続することによって、極めて容易に製造することができ、かつ電圧低下を低減して高性能化を図ることができる巻き電池およびその製造方法を提供することを目的とする。
【０００６】
【課題を解決するための手段】
上記の目的を達成するため、本発明は、正極活物質を含む正極活物質シートと、負極活物質を含む負極活物質シートとが電解質を含むセパレータを介して渦巻き状に捲回された電極体と、該電極体の軸方向の両端部にそれぞれ対向配置され、前記正極活物質シートに電気的に接続される正極外部端子および前記負極活物質シートに電気的に接続される負極外部端子とを備える巻き電池であって、電極体は、その軸方向の一端部に正極活物質シートが、他端部に負極活物質シートがそれぞれ突出するように、両シートを軸方向にずらした状態で重ね合わされて渦巻き状に捲回されてなり、前記セパレータは、前記正極活物質シートと前記負極活物質シートの間に介在し、前記負極活物質シートの突出方向と反対側の端部を覆うように一端部が折り曲げられた第１セパレータと、該第１セパレータとの間で前記正極活物質シートと前記負極活物質シートのいずれか一方を挟み込み、前記正極活物質シートの突出方向と反対側の端部を覆うように他端部が折り曲げられた第２セパレータとからなり、前記正極外部端子は、前記電極体の一端部に配置されて当接し、前記第１セパレータ及び前記第２セパレータの間から突出している前記正極活物質シートの端部に当接して電気的に接続されると共に前記第１セパレータの一端部を介して前記負極活物質シートの突出方向と反対側の端部と隔離され、前記負極外部端子は、前記電極体の他端部に配置されて当接し、前記第１セパレータ及び前記第２セパレータの間から突出している前記負極活物質シートの端部に当接して電気的に接続されると共に前記第２セパレータの他端部を介して前記正極活物質シートの突出方向と反対側の端部と隔離されていることを特徴とする。
【０００７】
一般的に、放電する際、電流は正極活物質シートから正極外部端子および負極外部端子を介して負極活物質シートへ流れるが、本発明の巻き電池では、電流の流れる経路に溶接箇所がないので、高出力放電しても電圧低下が少なく高性能な巻き電池を得ることができる。
【０００８】
また、本発明のセパレータは、正極活物質シートおよび負極活物質シートの突出方向と反対側の端部を覆うように構成されており、セパレータが正極活物質シートと負極活物質シートとを物理的に分離する。従って、何らかの外力によって突出している両シートのいずれかが変形した場合であっても、両シート間の電気絶縁を保つことができる。
【０００９】
また、本発明では、電極体をその外周部に巻き付けて結束する結束部材をさらに備える構成としてもよい。この構成によれば、結束部材が電極体の外周部に巻き付き電極体の形態を拘束し、これによって電極体の捲回状態を維持することができる。
【００１０】
また、本発明では、複数の電極体を備え、複数の電極体が、相対向して前記正極外部端子及び前記負極外部端子を構成する２つの面を有する容器内に並列的に配され、該正極外部端子が、前記複数の電極体の夫々の前記正極活物質シートの端部に当接して電気的に接続され、該負極外部端子が、前記複数の電極体の夫々の前記負極活物質シートの端部に当接して電気的に接続されていてもよい。これにより、複数の電極体が並列的に配されることによって電気的に並列接続されるので、電池容量を大きくすることができる。すなわち、この場合、電極体の両端間の電圧は変わらず、電流が増加する。
【００１１】
また、上記複数の電極体が、充放電特性の異なる複数の種類の電極体であってもよい。このように充放電特性の異なる複数の電極体を組み合わせることによって、使用目的に応じた巻き電池を構成することが可能となる。例えば、一種類の電極体では実現不可能である瞬間的な高電流と大きな電池容量とを同時に満足する巻き電池を提供することができる。
【００１２】
さらに、本発明では、前記容器が複数であり、該複数の容器が直列的に配され、互いに隣接する容器のうち一方の容器の正極外部端子と他方の容器の負極外部端子とが向かい合って当接していても良く、これにより、巻き電池の高電圧化が可能となる。
【００１３】
また、本発明に係る巻き電池の製造方法は、正極活物質を含む正極活物質シートと、負極活物質を含む負極活物質シートと、両シートの間に介在する第１セパレータと、該第１セパレータとの間で両シートのいずれか一方のシートを挟み込む第２セパレータとを、前記両セパレータの一端側の間から前記正極活物質シートが、前記両セパレータの他端側の間から前記負極活物質シートがそれぞれ突出するようにずらした状態で重ね合わせると共に、前記負極活物質シートの突出方向と反対側の端部を覆うように前記第１セパレータの一端部を折り曲げ、前記正極活物質シートの突出方向と反対側の端部を覆うように前記第２セパレータの他端部を折り曲げる第１工程と、重ね合わせた両シートおよび両セパレータを渦巻き状に捲回して電極体を形成する第２工程と、前記電極体の軸方向の一端部と正極外部端子とを当接させることにより、該正極外部端子を前記第１セパレータ及び前記第２セパレータの間から突出している前記正極活物質シートの端部に当接させて電気的に接続し、前記電極体の軸方向の他端部と負極外部端子とを当接させることにより、該負極外部端子を前記第１セパレータ及び前記第２セパレータの間から突出している前記負極活物質シートの端部に当接させて電気的に接続する第３工程とを備えることを特徴とする。
【００１４】
この構成によれば、両セパレータに対して両シートを相互に反対方向にずらした状態で重ね合わせ渦巻き状に捲回するので、これにより形成される電極体の各端部には互いに異なる極性を突出させることが可能となる。すなわち、電極体の一端部には正極活物質シートが、他端部には負極活物質シートが突出する。また、電極体の突出している正極活物質シートを正極外部端子に、電極体の突出している負極活物質シートを負極外部端子にそれぞれ当接することにより電気的に接続しているので、従来の巻き電池で行っていた溶接工程が不要となる。その結果、巻き電池の製造が極めて容易となり、その製造期間も短縮でき、さらにコストも低減することができる。
【００１５】
また、上記第１工程が、正極活物質シートおよび／または負極活物質シートの突出方向と反対側の端部をそれぞれ覆うように第１セパレータおよび／または第２セパレータの端部を折り曲げる工程を含んでいることにより、正極活物質シートと負極活物質シートとが電気絶縁性の両セパレータによって物理的に分離されるので、これらの間の電気絶縁を確実に行うことができる。
【００１６】
また、上記第２工程が、捲回された両シートおよび両セパレータの外周部を結束部材で巻き付けて結束する工程をさらに含んでもよい。これにより、両シートおよび両セパレータの捲回状態を維持することができる。
【００１７】
また、本発明に係る巻き電池がニッケル水素電池であってもよい。ニッケル水素電池は、クリーンで環境適合性のある電池として、近年、電気自動車などに使用されている。本発明に係る巻き電池の構造をニッケル水素電池に適用することにより、ニッケル水素電池の大容量化並びに高電圧化が可能となり前記電気自動車などへの適用が容易となる。
【００１８】
【発明の実施の形態】
以下、図面を用いて本発明に係る巻き電池の実施の形態について説明する。本発明に係る巻き電池の特徴部は電極体である。そこで、まず、巻き電池の電極体について説明する。
【００１９】
図１は、本発明に係る巻き電池の電極体の構造の一例を示しており、図１（ａ）、（ｂ）は、それぞれ電極体の部分切欠斜視図および電極体の平面図を示している。
【００２０】
図１（ａ）に示すように、略円筒状の電極体１は、正極活物質を含む正極活物質シート２と、負極活物質層を含む負極活物質シート４と、両シート２、４間に介在し両シート２、４間を電気絶縁すると共に、その中に含まれる電解液を介してイオンを伝導させる板状の第１セパレータ３０と、該第１セパレータ３０との間に正極活物質シート４を挟み込む第２セパレータ３１とを備える。そして、負極活物質シート４、第１セパレータ３０、正極活物質シート２および第２セパレータ３１は、この順に密着するように重ね合わされており、電極体１の最外周層が負極活物質シート４になるように渦巻き状に捲回されている（図１（ｂ）参照）。すなわち、第１セパレータ３０と第２セパレータ３１とが、電極体１の径方向内方に向かって正極活物質シート２と負極活物質シート４との間に形成される複数の層間に交互に介在する。ここでは、電極体１の最外周層が負極活物質シート４になるように構成されているが、正極活物質シート２に替えても構わない。
【００２１】
また、電極体１の軸方向の一端部４ａ（図１（ａ）中、上方の端部）には、負極活物質シート４が突出しており、電極体１の軸方向の他端部２ａ（図１（ａ）中、下方の端部）には、正極活物質シート２が突出している。負極活物質シート４の突出方向と反対側の端部４ｂは、電極体１の径方向外方に折り曲げられた第１セパレータ３０の端部３０ａによって覆われている。また、正極活物質シート２の突出方向と反対側の端部２ｂは、第１セパレータ３０の折り曲げらた端部３０ａと反対側の端部３０ｂと、電極体１の径方向外方に折り曲げられた第２セパレータ３１の端部３１ａとによって覆われている。これらの端部３０ｂ、３１ａは断面略コ字状になるように形成され、これによって形成された凹部に正極活物質シート２の突出方向と反対側の端部２ｂが内装されるように構成されている。以上の構成により、電極体１の正極活物質シート２と負極活物質シート４との接触（電気的な短絡）を防止することができる。なお、ここで示した第１セパレータ３０および第２セパレータ３１の端部３０ａ、３１ａを折り曲げる構造は一例であり、これに限定するものではない。
【００２２】
また、電極体１の渦巻き状の両端部２ａ、４ａはその軸方向に対して略直角になるように形成されており、略平坦な板状の正極外部端子（図示せず）および負極外部端子（図示せず）にそれぞれ均一に当接するように押圧されている。この構成では溶接部がないので、溶接部の電気抵抗による大きな電圧低下はない。これにより、巻き電池の高性能化が可能となる。
【００２３】
次に、ニッケル水素電池を一例として、上記の電極体１を構成する部品の材料について説明する。なお、以下に示す材料は、巻き電池の種類に応じて適宜変更される。
【００２４】
正極活物質シート２は、導電性の発砲ニッケルなどの板状体に水酸化ニッケル（正極活物質）を塗布して発砲ニッケルの細孔に充填し、乾燥したあと所定の厚みに圧延して形成されている。負極活物質シート４は、導電性の発砲ニッケルなど板状体に水素吸蔵合金粉末（負極活物質）を塗布して発砲ニッケルの細孔に充填し、乾燥したあと所定の厚みに圧延して形成されている。第１セパレータ３０および第２セパレータ３１は、電気絶縁物質であるポリプロピレン、ポリエチレンまたはポリアミドなどから構成される。また、両セパレータ３０、３１としては、メッシュ（網）または不織布などを採用することが好ましい。これにより、両セパレータ３０、３１は多くの電解液を保持することができる。その結果、正極活物質シート２と負極活物質シート４との間でのイオンの伝導が容易となる。電解質は、水酸化カリウムが使用される。
【００２５】
この場合の電池反応を簡単に説明すると、放電状態では、負極活物質シート４に吸蔵されている水素が水素イオンとなって（電子を外部放電回路に放つ）第１または第２セパレータ３０、３１内に含まれる電解液中を通り正極活物質シート２に達する。そこで、オキシ水酸化ニッケルと反応して（電子を得て）水酸化ニッケルになる。充電状態では、この逆の反応が起こる。
【００２６】
次に、上記電極体１の製造方法について図２に基づいて説明する。
【００２７】
まず、図２（ａ）に示すように、略長板状であって略同一形状を有する正極活物質シート２、負極活物質シート４、第１セパレータ３０および第２セパレータ３１を製作する。負極活物質シート４、第１セパレータ３０、正極活物質シート２および第２セパレータ３１は、この順に重ね合わされる。その後、正極活物質シート２は、第１セパレータ３０および第２セパレータ３１の一端側から突出するように（図２（ａ）の下方に）所定量ずらす。一方、負極活物質シート４は、第１セパレータ３０および第２セパレータ３１の他端側から突出するように（図２（ａ）の上方に）所定量ずらす。この場合、第１セパレータ３０および第２セパレータ３１の位置は変化しない。従って、両セパレータ３０、３１は、その板厚方向に相対向するように配置される。なお、上記「所定量」としては１ｍｍ程度でよいが、実際には、突出している正極活物質シート２および負極活物質シート４の形状、材質、加工精度などを考慮して設定される。
【００２８】
その後、図２（ｂ）に示すように、負極活物質シート４をずらした方向と反対側の端部４ｂを覆うために、第１セパレータ３０の端部３０ａは、その板厚方向の、負極活物質シート４側に略垂直に折り曲げられる。同様に、正極活物質シート２をずらした方向と反対側の端部２ａを覆うために、第２セパレータ３１の端部３１ａは、その板厚方向の、正極活物質シート２側に略垂直に折り曲げられる。これにより、正極活物質シート２、負極活物質シート４、第１セパレータ３ａおよび第２セパレータ３ｂを捲回するときに巻きずれなどを起こした場合であっても、正極活物質シート２と負極活物質シート４との接触（電気的な短絡）を防止することができる。なお、ここでは、両セパレータ３０、３１の端部３０ａ、３１ａを折り曲げる工程を有するが、正極活物質シート２と負極活物質シート４との電気絶縁を維持するように上記「所定量」を設定すれば、この工程を省略することも可能である。これにより、電極体１の製造が容易となる。
【００２９】
その後、図２（ｃ）に示すように、負極活物質シート４、第１セパレータ３０、正極活物質シート２および第２セパレータ３１を重ね合わせたものを、その長手方向に渦巻き状に捲回する。これにより、略円筒状の電極体１が形成され、その各端部２ａ、４ａには互いに異なる極性が形成される。すなわち、電極体１の一端部２ａに正極活物質シート２が、他端部４ａに負極活物質シート４がそれぞれ突出することになる。
【００３０】
その後、電極体１の形態の安定性を考慮して、図２（ｄ）に示すように、電極体１の外周部に帯状の結束部材５を巻き付け、該結束部材５の両端部５ａを熱融着などで接着してもよい。この例では、２箇所に結束部材５を巻き付けているが、その数は電極体１を構成する材料などに応じて適宜設定される。また、結束部材５も、第１セパレータ３０などと同様耐電解液性が要求される。そのため、結束部材５は、電気絶縁物質であるポリプロピレン、ポリエチレンまたはポリアミドなどからなる。さらに、結束部材５は、その中に電解液を多く含みイオンを伝導させる必要があるため、メッシュ（網）または不織布などから構成されることが好ましい。なお、結束部材５を電極体１に巻き付ける工程は、捲回された電極体１の形態が安定している場合には、省略しても構わない。
【００３１】
その後、電極体１が後述の電池容器Ｂなどに収納され、電池容器Ｂ内に電解液を充填し、電池容器Ｂ全体を密封して後述の捲き電池Ｄが形成される（図示せず）。電池容器Ｂに電極体１を収納する際、電極体１の各端部と電池容器Ｂとの接続部は、溶接されず当接される。
【００３２】
上記のように本実施の形態に係る電極体１および巻き電池Ｄの製造過程では、溶接工程がない。従って、その製造は極めて容易となる。その結果、巻き電池の製造時間を短縮することができ、製造コストも低減することができる。なお、上記の電極体１の製造方法は一例であり、これに限定されるものではない。
【００３３】
次に、上記電極体１を用いて構成した本発明の実施の形態に係る巻き電池について図１および図３に基づいて説明する。図３は、本発明の実施形態に係る巻き電池の斜視図である。図３（ａ）は、巻き電池の形状が箱形状である場合を示し、図３（ｂ）は、円筒形状である場合を示している。
【００３４】
図３（ａ）に示すように、巻き電池Ｄは複数の電極体１とこれらを収納する電池容器Ｂを備える。電池容器Ｂは全体として箱形状をなしており、その内相対向する２つの面が、それぞれ正極外部端子６と負極外部端子７とを構成する。両端子６、７とその他の面８との接続部には、電気絶縁材１０が介在しており、両端子６、７間は電気絶縁されている。なお、正極外部端子６および負極外部端子７には、電気配線などを接続するため帯状などの接続端子（図示せず）をそれぞれ設けても構わない。
【００３５】
上記電池容器Ｂ内には、複数の電極体１が収納され、これらは並列的に配置されている。図１に示した電極体１の突出している正極活物質シート２が正極端外部端子６に、電極体１の突出している負極活物質シート４が負極外部端子７に当接され、電気的に並列接続されている。
【００３６】
以上のように複数の電極体１を並列的に配置することによって、大きな電流を得る（大容量化する）ことができる。また、電極体１の突出している正極活物質シート２が正極外部端子６に、電極体１の突出している負極活物質シート２が負極外部端子７にそれぞれ当接するのみで溶接してしないので、溶接部の電気抵抗による電圧低下がない。これにより、巻き電池Ｄの高性能化が可能となる。
【００３７】
また、電池容器Ｂに収納される電極体１は、全て同一の充放電特性を有するものでも、異なる充放電特性を有するものの組合せであっても構わない。後者の例として、瞬間的に大電流を充放電する特性を有する電極体１と、小電流しか流せないが長時間充放電する（電気容量が大きい）特性を有する電極体１との組合せが挙げられる。これにより、瞬間的に大電流を充放電し、かつ長時間充放電することができる。例えば、本発明の実施の形態に係る巻き電池は、加速する際に瞬間的な大電流を要し、走行距離を長くするために大きな電気容量を要するような電気自動車または電気自転車などに適用される。なお、充放電特性の異なる電極体１の組合せは、巻き電池Ｄの用途に応じて適宜設定される。
【００３８】
また、電池容器Ｂの形状は、図３（ｂ）に示すように略円筒状であっても良い。図示するように、電池容器Ｂは円筒胴８ａ並びにこの両端の開口をそれぞれ覆う円板状の正極外部端子６および負極外部端子７を備える。両端子６、７と円筒胴８ａとの接続部分には、電気絶縁材１０が介在し、両端子６、７間の電気絶縁が保たれている。電池容器Ｂ内には、電極体１が並列的に配置されて収納されており、図１に示した電極体１の突出している正極活物質シート２が正極外部端子６に、電極体１の突出している負極活物質シート４が負極外部端子７にそれぞれ当接され、電気的に並列接続されている。
【００３９】
以上の構成により、電池容器Ｂの機械的な強度を向上させることができる。また、電池容器Ｂの接続箇所が少ないので、電池容器Ｂ内の電解液の漏れなどを防止することも容易である。
【００４０】
なお、ここでは、複数の電極体１を収納する場合について説明したが、もちろん、一つの電極体１を収納する場合であっても構わない。また、上述した例では、電池容器Ｂ内に複数の電極体１を並列的に収納する場合ついて説明したが、その他のものとして複数の電池容器Ｂを並列的に配置して大電流化を図っても良い。これにより、運搬可能なサイズの電池容器Ｂで構成したり、充放電特性の異なる電池容器Ｂで構成したりすることが容易となる。
【００４１】
次に、本発明の別の実施の形態に係る巻き電池について図４を用いて説明する。図４は、本発明の別の実施の形態に係る巻き電池の斜視図を示している。なお、ここでは、図３（ｂ）に示した円筒状の巻き電池Ｄを一例として説明する。
【００４２】
図４に示すように、４つの巻き電池Ｄが直列的に配置されている。各巻き電池Ｄの正極外部端子６と負極外部端子７とは、図３（ｂ）で示したように略平坦な円板状であり、互いに隣接する巻き電池Ｄの正極外部端子６および負極外部端子７とは互いに向かい合って当接している。以上のように巻き電池Ｄを直列配置することで高電圧化を図ることが可能となる。さらに、正極外部端子６と負極外部端子７とが当接する部分の面積を大きいので、この部分における電圧低下を小さくすることができる。なお、ここでは、巻き電池Ｄの数は４つであるが、この数に限定されるものではない。
【００４３】
なお、以上の巻き電池の構造および製造方法は、上述したニッケル水素電池以外にも、ニッケルカドミウム電池、リチウム電池、リチウムイオン電池、鉛蓄電池、マンガン電池など、また、一次電池、二次電池、電気二重層キャパシタ（コンデンサ）、電気二重層化学キャパシタ（コンデンサ）などにも適用することができる。
【００４４】
【発明の効果】
本発明に係る巻き電池は、電極体の正極活物質シートを正極外部端子に、電極体の負極活物質シートを負極外部端子にそれぞれ溶接せず当接により電気的に接続することによって、高出力放電する場合にあっても電圧低下を低減して高性能化を図ることができる。
【００４５】
また、本発明に係る巻き電池の製造方法では、溶接工程が不要であるので、巻き電池を極めて容易に製作することができる。
【図面の簡単な説明】
【図１】本発明に係る巻き電池の電極体の構造の一例を示す図である。
【図２】本発明に係る巻き電池の電極体の製造工程を示す図である。
【図３】本発明の実施形態に係る巻き電池の斜視図である。
【図４】本発明の別の実施の形態に係る巻き電池の斜視図である。
【符号の説明】
１電極体
２正極活物質シート
２ａ電極体の軸方向の他端部
３０第１セパレータ
３１第２セパレータ
４負極活物質シート
４ａ電極体の軸方向の一端部
５、５ａ結束部材
６正極外部端子
７負極外部端子
Ｂ電池容器
Ｄ巻き電池[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wound battery using an electrode body formed by stacking and winding a positive electrode active material sheet, a separator, and a negative electrode active material sheet, and a method for manufacturing the same.
[0002]
[Prior art]
A cylindrical wound battery represented by a nickel metal hydride battery has a positive electrode active material sheet containing a positive electrode active material (such as nickel hydroxide) and a negative electrode active material sheet containing a negative electrode active material (such as a hydrogen storage alloy). An electrode body wound in a spiral shape is provided through a plate-shaped separator that electrically insulates between both sheets and conducts ions through an electrolyte contained therein. The outermost peripheral layer of the electrode body is configured to be a negative electrode active material sheet, and is housed in a bottomed cylindrical battery container having an opening at one end also serving as a negative electrode external terminal. The opening of the battery container is covered with a plate-like positive external terminal projecting at the center thereof, whereby the positive external terminal constitutes a part of the battery container (see, for example, Patent Document 1). ). Moreover, the positive electrode external terminal and the positive electrode active material sheet of the electrode body are each welded via conductive tabs, such as nickel (for example, refer patent document 2).
[0003]
[Patent Document 1]
JP 2002-8710 A (page 1, FIG. 1)
[Patent Document 2]
Japanese Patent Laid-Open No. 5-234616 (page 3, FIG. 1)
[0004]
[Problems to be solved by the invention]
However, in the structure of the wound battery described above, there are two welds in the path on the positive electrode side through which electricity flows. Due to the electrical resistance of the welded portion, when the wound battery is discharged at a high output, the voltage across the wound battery is lowered, and the performance of the wound battery cannot be sufficiently ensured. Moreover, since there exists a welding part, the manufacturing time of a winding battery takes much, and manufacturing cost also increases.
[0005]
The present invention has been made in view of the above-described problems. The positive electrode active material sheet of the electrode body is electrically connected to the positive electrode external terminal and the negative electrode active material sheet of the electrode body is not welded to the negative electrode external terminal. It is an object of the present invention to provide a wound battery and a method for manufacturing the same that can be manufactured very easily by reducing the voltage drop and can improve performance.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides an electrode body in which a positive electrode active material sheet containing a positive electrode active material and a negative electrode active material sheet containing a negative electrode active material are wound in a spiral shape through a separator containing an electrolyte. And a positive external terminal electrically connected to the positive active material sheet and a negative external terminal electrically connected to the negative active material sheet, which are respectively opposed to both end portions in the axial direction of the electrode body. The electrode body is stacked in a state where both sheets are shifted in the axial direction so that the positive electrode active material sheet protrudes at one end in the axial direction and the negative electrode active material sheet protrudes from the other end, respectively. The separator is interposed between the positive electrode active material sheet and the negative electrode active material sheet so as to cover the end of the negative electrode active material sheet opposite to the protruding direction. One end is folded One of the positive electrode active material sheet and the negative electrode active material sheet is sandwiched between the bent first separator and the first separator, and covers the end of the positive electrode active material sheet opposite to the protruding direction. The positive electrode external terminal is disposed at and abuts one end of the electrode body and protrudes from between the first separator and the second separator . the positive electrode active material through one end portion of the first separator along with the end of the sheet abuts and is electrically connected the isolated negative electrode active projecting direction of material sheet and an opposite end portion, the negative electrode external terminal is disposed on the other end portion of the electrode body in contact, it is electrically connected in contact with the end portion of the anode active material sheet which protrudes from between the first separator and the second separator Characterized in that it is both isolated and the end opposite to the protruding direction of the second separator other end the positive electrode active material sheet through the.
[0007]
In general, when discharging, the current flows from the positive electrode active material sheet to the negative electrode active material sheet via the positive electrode external terminal and the negative electrode external terminal. However, in the wound battery of the present invention, there is no welding point in the current flow path. A high-performance wound battery with little voltage drop even with high output discharge can be obtained.
[0008]
In addition, the separator of the present invention is configured to cover the ends of the positive electrode active material sheet and the negative electrode active material sheet opposite to the protruding direction, and the separator physically separates the positive electrode active material sheet and the negative electrode active material sheet. To separate. Therefore, even if one of the two sheets protruding by some external force is deformed, the electric insulation between the two sheets can be maintained.
[0009]
Moreover, in this invention, it is good also as a structure further equipped with the binding member which winds and binds an electrode body to the outer peripheral part. According to this configuration, the binding member wraps around the outer periphery of the electrode body and restricts the form of the electrode body, thereby maintaining the wound state of the electrode body.
[0010]
In the present invention, a plurality of electrode bodies are provided, and the plurality of electrode bodies are arranged in parallel in a container having two surfaces that face each other and constitute the positive electrode external terminal and the negative electrode external terminal , A positive electrode external terminal is in contact with and electrically connected to an end of the positive electrode active material sheet of each of the plurality of electrode bodies, and the negative electrode external terminal is connected to the negative electrode active material sheet of each of the plurality of electrode bodies. It may be in contact with and electrically connected to the end of the . Thereby, since a plurality of electrode bodies are arranged in parallel and electrically connected in parallel, the battery capacity can be increased. That is, in this case, the voltage across the electrode body does not change, and the current increases.
[0011]
The plurality of electrode bodies may be a plurality of types of electrode bodies having different charge / discharge characteristics. Thus, by combining a plurality of electrode bodies having different charge / discharge characteristics, a wound battery according to the purpose of use can be configured. For example, it is possible to provide a wound battery that simultaneously satisfies an instantaneous high current and a large battery capacity that cannot be realized with one type of electrode body.
[0012]
Furthermore, in the present invention, the container is a plurality, the plurality of containers are arranged in series, those facing each other and the negative electrode external terminal of positive electrode external terminal and the other container of one container of the container adjacent to each other It may be in contact, which enables a high-voltage winding battery.
[0013]
In addition, a method for manufacturing a wound battery according to the present invention includes a positive electrode active material sheet containing a positive electrode active material, a negative electrode active material sheet containing a negative electrode active material, a first separator interposed between both sheets, and the first A second separator that sandwiches one of the two sheets between the separator and the positive electrode active material sheet from between one end sides of the two separators, and the negative electrode active sheet from between the other end sides of the two separators. The material sheets are superposed in a shifted state so as to protrude, and one end of the first separator is folded so as to cover the end opposite to the protruding direction of the negative electrode active material sheet, a first step of bending the other end portion of the second separator so as to cover the end portion of the protruding direction opposite to the sheets and the separators superimposed and wound spirally electrode member A second step of forming, by abutting the end portion in the axial direction and the positive electrode external terminal of the electrode body, the positive electrode of the positive electrode external terminal protruding from between the first separator and the second separator The negative electrode external terminal is brought into contact with the end portion of the active material sheet and electrically connected, and the negative electrode external terminal is brought into contact with the other end portion in the axial direction of the electrode body and the negative electrode external terminal. And a third step of contacting and electrically connecting to an end portion of the negative electrode active material sheet protruding from between the second separators .
[0014]
According to this configuration, since both sheets are shifted in opposite directions with respect to both separators and wound in a spiral shape, each end of the electrode body formed thereby has different polarities. It can be projected. That is, the positive electrode active material sheet protrudes from one end of the electrode body, and the negative electrode active material sheet protrudes from the other end. Further, since the positive electrode active material sheet protruding from the electrode body is electrically connected to the positive electrode external terminal and the negative electrode active material sheet protruding from the electrode body is brought into contact with the negative electrode external terminal, the conventional winding is performed. The welding process performed by the battery becomes unnecessary. As a result, the winding battery can be manufactured very easily, the manufacturing period can be shortened, and the cost can be reduced.
[0015]
Further, the first step includes a step of bending the end portions of the first separator and / or the second separator so as to cover the end portions on the opposite side to the protruding direction of the positive electrode active material sheet and / or the negative electrode active material sheet, respectively. by being de, since the positive electrode active material sheets and the negative electrode active material sheet is physically separated by electrically insulating the separators, it is possible to perform electrical insulation between them reliably.
[0016]
Moreover, the said 2nd process may further include the process of winding and winding the outer peripheral part of both the wound sheet | seats and both separators with a binding member. Thereby, the winding state of both sheets and both separators can be maintained.
[0017]
Further, the wound battery according to the present invention may be a nickel metal hydride battery. In recent years, nickel metal hydride batteries have been used in electric vehicles and the like as clean and environmentally friendly batteries. By applying the structure of the wound battery according to the present invention to a nickel-metal hydride battery, the capacity and voltage of the nickel-metal hydride battery can be increased and the application to the electric vehicle or the like is facilitated.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a wound battery according to the present invention will be described below with reference to the drawings. The characteristic part of the wound battery according to the present invention is an electrode body. Therefore, first, the electrode body of the wound battery will be described.
[0019]
FIG. 1 shows an example of the structure of an electrode body of a wound battery according to the present invention. FIGS. 1 (a) and 1 (b) show a partially cutaway perspective view of the electrode body and a plan view of the electrode body, respectively. Yes.
[0020]
As shown in FIG. 1A, a substantially cylindrical electrode body 1 includes a positive electrode active material sheet 2 including a positive electrode active material, a negative electrode active material sheet 4 including a negative electrode active material layer, and a space between both sheets 2 and 4. A positive electrode active material between the first separator 30 and a plate-shaped first separator 30 that is interposed between the sheet 2 and 4 and electrically conducts ions through the electrolyte contained therein. And a second separator 31 that sandwiches the sheet 4. And the negative electrode active material sheet 4, the 1st separator 30, the positive electrode active material sheet 2, and the 2nd separator 31 are piled up so that it may contact | adhere in this order, and the outermost periphery layer of the electrode body 1 is on the negative electrode active material sheet 4 It is wound in a spiral shape (see FIG. 1B). That is, the first separator 30 and the second separator 31 are alternately interposed between a plurality of layers formed between the positive electrode active material sheet 2 and the negative electrode active material sheet 4 inward in the radial direction of the electrode body 1. To do. Here, the outermost peripheral layer of the electrode body 1 is configured to be the negative electrode active material sheet 4, but may be replaced with the positive electrode active material sheet 2.
[0021]
Moreover, the negative electrode active material sheet 4 protrudes from one end portion 4a in the axial direction of the electrode body 1 (the upper end portion in FIG. 1A), and the other end portion 2a in the axial direction of the electrode body 1 ( The positive electrode active material sheet 2 protrudes from the lower end portion in FIG. An end 4 b opposite to the protruding direction of the negative electrode active material sheet 4 is covered with an end 30 a of the first separator 30 bent outward in the radial direction of the electrode body 1. Further, the end 2 b opposite to the protruding direction of the positive electrode active material sheet 2 is bent outward in the radial direction of the electrode body 1 with the end 30 b opposite to the bent end 30 a of the first separator 30. The second separator 31 is covered with the end 31a. These end portions 30b and 31a are formed so as to have a substantially U-shaped cross section, and the end portion 2b opposite to the protruding direction of the positive electrode active material sheet 2 is configured to be embedded in the recess formed thereby. ing. With the above configuration, contact (electrical short circuit) between the positive electrode active material sheet 2 and the negative electrode active material sheet 4 of the electrode body 1 can be prevented. In addition, the structure which bend | folds the edge parts 30a and 31a of the 1st separator 30 shown here and the 2nd separator 31 is an example, and is not limited to this.
[0022]
Further, the spiral end portions 2a and 4a of the electrode body 1 are formed so as to be substantially perpendicular to the axial direction, and are substantially flat plate-like positive external terminals (not shown) and negative external terminals. (Not shown) are pressed so as to uniformly contact each other. Since there is no weld in this configuration, there is no significant voltage drop due to the electrical resistance of the weld. Thereby, the performance of the wound battery can be improved.
[0023]
Next, taking a nickel metal hydride battery as an example, the material of the parts constituting the electrode body 1 will be described. In addition, the material shown below is suitably changed according to the kind of winding battery.
[0024]
The positive electrode active material sheet 2 is formed by applying nickel hydroxide (positive electrode active material) to a plate-like body such as conductive foam nickel, filling the pores of the foam nickel, drying, and rolling to a predetermined thickness. Has been. The negative electrode active material sheet 4 is formed by applying hydrogen storage alloy powder (negative electrode active material) to a plate-like body such as conductive foam nickel, filling the pores of the foam nickel, drying, and rolling to a predetermined thickness. Has been. The first separator 30 and the second separator 31 are made of an electrically insulating material such as polypropylene, polyethylene, or polyamide. Moreover, as both separators 30 and 31, it is preferable to employ | adopt a mesh (net | network) or a nonwoven fabric. Thereby, both separators 30 and 31 can hold | maintain many electrolyte solutions. As a result, ion conduction between the positive electrode active material sheet 2 and the negative electrode active material sheet 4 is facilitated. As the electrolyte, potassium hydroxide is used.
[0025]
The battery reaction in this case will be briefly described. In the discharged state, hydrogen occluded in the negative electrode active material sheet 4 becomes hydrogen ions (releases electrons to the external discharge circuit). It reaches the positive electrode active material sheet 2 through the electrolyte contained therein. Therefore, it reacts with nickel oxyhydroxide (acquires electrons) to become nickel hydroxide. In the charged state, the reverse reaction occurs.
[0026]
Next, a method for manufacturing the electrode body 1 will be described with reference to FIG.
[0027]
First, as shown in FIG. 2A, a positive electrode active material sheet 2, a negative electrode active material sheet 4, a first separator 30, and a second separator 31 that are substantially long and have the same shape are manufactured. The negative electrode active material sheet 4, the first separator 30, the positive electrode active material sheet 2 and the second separator 31 are stacked in this order. Thereafter, the positive electrode active material sheet 2 is shifted by a predetermined amount so as to protrude from one end side of the first separator 30 and the second separator 31 (downward in FIG. 2A). On the other hand, the negative electrode active material sheet 4 is shifted by a predetermined amount so as to protrude from the other end sides of the first separator 30 and the second separator 31 (upward in FIG. 2A). In this case, the positions of the first separator 30 and the second separator 31 do not change. Therefore, both separators 30 and 31 are disposed so as to face each other in the plate thickness direction. The “predetermined amount” may be about 1 mm, but is actually set in consideration of the shape, material, processing accuracy, and the like of the protruding positive electrode active material sheet 2 and negative electrode active material sheet 4.
[0028]
Thereafter, as shown in FIG. 2B, in order to cover the end 4b opposite to the direction in which the negative electrode active material sheet 4 is shifted, the end 30a of the first separator 30 has a negative electrode in the plate thickness direction. It is bent substantially perpendicularly to the active material sheet 4 side. Similarly, in order to cover the end 2a opposite to the direction in which the positive electrode active material sheet 2 is shifted, the end 31a of the second separator 31 is substantially perpendicular to the positive electrode active material sheet 2 side in the plate thickness direction. It can be bent. As a result, even when the positive electrode active material sheet 2, the negative electrode active material sheet 4, the first separator 3 a, and the second separator 3 b are wound up, Contact (electrical short circuit) with the material sheet 4 can be prevented. Here, although there is a step of bending the end portions 30a, 31a of both separators 30, 31, the above "predetermined amount" is set so as to maintain electrical insulation between the positive electrode active material sheet 2 and the negative electrode active material sheet 4 If this is the case, this step can be omitted. Thereby, manufacture of the electrode body 1 becomes easy.
[0029]
Thereafter, as shown in FIG. 2 (c), a stack of the negative electrode active material sheet 4, the first separator 30, the positive electrode active material sheet 2 and the second separator 31 is spirally wound in the longitudinal direction thereof. . Thereby, the substantially cylindrical electrode body 1 is formed, and the polarities different from each other are formed at each of the end portions 2a and 4a. That is, the positive electrode active material sheet 2 protrudes from the one end 2a of the electrode body 1 and the negative electrode active material sheet 4 protrudes from the other end 4a.
[0030]
Thereafter, in consideration of the stability of the form of the electrode body 1, as shown in FIG. 2 (d), a band-like binding member 5 is wound around the outer periphery of the electrode body 1, and both ends 5 a of the binding member 5 are heated. You may adhere | attach by melt | fusion etc. In this example, the binding members 5 are wound around two places, but the number is appropriately set according to the material constituting the electrode body 1 and the like. The bundling member 5 is also required to have an electrolytic solution resistance, like the first separator 30 and the like. Therefore, the binding member 5 is made of an electrically insulating material such as polypropylene, polyethylene, or polyamide. Furthermore, since the binding member 5 needs to contain a large amount of electrolytic solution therein and conduct ions, it is preferable that the binding member 5 is composed of a mesh or a nonwoven fabric. Note that the step of winding the binding member 5 around the electrode body 1 may be omitted when the shape of the wound electrode body 1 is stable.
[0031]
Thereafter, the electrode body 1 is housed in a battery container B or the like described later, and the battery container B is filled with an electrolytic solution, and the whole battery container B is sealed to form a fired battery D described later (not shown). When the electrode body 1 is housed in the battery case B, the connection portions between the end portions of the electrode body 1 and the battery case B are brought into contact without being welded.
[0032]
As described above, in the manufacturing process of the electrode body 1 and the wound battery D according to the present embodiment, there is no welding process. Therefore, its manufacture becomes extremely easy. As a result, the manufacturing time of the wound battery can be shortened, and the manufacturing cost can also be reduced. In addition, the manufacturing method of said electrode body 1 is an example, and is not limited to this.
[0033]
Next, a wound battery according to an embodiment of the present invention configured using the electrode body 1 will be described with reference to FIGS. 1 and 3. FIG. 3 is a perspective view of the wound battery according to the embodiment of the present invention. FIG. 3A shows a case where the shape of the wound battery is a box shape, and FIG. 3B shows a case where the shape is a cylindrical shape.
[0034]
As shown in FIG. 3 (a), the wound battery D includes a plurality of electrode bodies 1 and a battery container B for housing them. The battery container B has a box shape as a whole, and two surfaces facing the inner phase constitute a positive external terminal 6 and a negative external terminal 7, respectively. An electrical insulating material 10 is interposed at the connection between the terminals 6 and 7 and the other surface 8, and the terminals 6 and 7 are electrically insulated. The positive electrode external terminal 6 and the negative electrode external terminal 7 may each be provided with a strip-like connection terminal (not shown) for connecting electric wiring or the like.
[0035]
In the battery container B, a plurality of electrode bodies 1 are accommodated and arranged in parallel. The positive electrode active material sheet 2 protruding from the electrode body 1 shown in FIG. 1 is brought into contact with the positive end external terminal 6, and the negative electrode active material sheet 4 protruding from the electrode body 1 is brought into contact with the negative electrode external terminal 7. Connected in parallel.
[0036]
A large current can be obtained (capacity can be increased) by arranging the plurality of electrode bodies 1 in parallel as described above. In addition, since the positive electrode active material sheet 2 protruding from the electrode body 1 is in contact with the positive electrode external terminal 6 and the negative electrode active material sheet 2 protruding from the electrode body 1 is only in contact with the negative electrode external terminal 7, welding is not performed. There is no voltage drop due to the electrical resistance of the weld. Thereby, the high performance of the wound battery D is attained.
[0037]
Further, the electrode bodies 1 housed in the battery container B may all have the same charge / discharge characteristics or a combination of those having different charge / discharge characteristics. As an example of the latter, there is a combination of an electrode body 1 having a characteristic of charging / discharging a large current instantaneously and an electrode body 1 having a characteristic of charging / discharging for a long time (large electric capacity) while allowing only a small current to flow. It is done. Thereby, a large current can be charged and discharged instantaneously and charged and discharged for a long time. For example, the wound battery according to the embodiment of the present invention is applied to an electric vehicle or an electric bicycle that requires a large current instantaneously when accelerating and requires a large electric capacity in order to extend a travel distance. The In addition, the combination of the electrode bodies 1 having different charge / discharge characteristics is appropriately set according to the use of the wound battery D.
[0038]
Further, the shape of the battery container B may be substantially cylindrical as shown in FIG. As shown in the figure, the battery case B includes a cylindrical body 8a and disk-shaped positive external terminals 6 and negative external terminals 7 covering the openings at both ends, respectively. An electrical insulating material 10 is interposed at the connecting portion between both terminals 6 and 7 and the cylindrical body 8a, and electrical insulation between both terminals 6 and 7 is maintained. In the battery container B, the electrode bodies 1 are arranged and accommodated in parallel, and the positive electrode active material sheet 2 protruding from the electrode body 1 shown in FIG. The protruding negative electrode active material sheets 4 are in contact with the negative electrode external terminals 7 and are electrically connected in parallel.
[0039]
With the above configuration, the mechanical strength of the battery container B can be improved. Moreover, since there are few connection places of the battery container B, it is also easy to prevent the electrolyte solution in the battery container B from leaking.
[0040]
In addition, although the case where the several electrode body 1 was accommodated was demonstrated here, of course, you may be the case where one electrode body 1 is accommodated. In the above-described example, the case where the plurality of electrode bodies 1 are accommodated in parallel in the battery container B has been described. However, as an alternative, a plurality of battery containers B are arranged in parallel to increase the current. May be. Thereby, it becomes easy to comprise with the battery container B of the size which can be conveyed, or to comprise with the battery container B from which charging / discharging characteristics differ.
[0041]
Next, a wound battery according to another embodiment of the present invention will be described with reference to FIG. FIG. 4 shows a perspective view of a wound battery according to another embodiment of the present invention. Here, the cylindrical wound battery D shown in FIG. 3B will be described as an example.
[0042]
As shown in FIG. 4, four wound batteries D are arranged in series. The positive electrode external terminal 6 and the negative electrode external terminal 7 of each wound battery D have a substantially flat disk shape as shown in FIG. 3B, and the positive electrode external terminal 6 and the negative electrode external of the wound battery D adjacent to each other. The terminals 7 are in contact with each other. As described above, it is possible to increase the voltage by arranging the wound batteries D in series. Furthermore, since the area of the part where the positive electrode external terminal 6 and the negative electrode external terminal 7 abut is large, the voltage drop at this part can be reduced. In addition, although the number of the winding batteries D is four here, it is not limited to this number.
[0043]
In addition to the nickel metal hydride battery described above, the structure and manufacturing method of the above wound battery include nickel cadmium battery, lithium battery, lithium ion battery, lead storage battery, manganese battery, etc., primary battery, secondary battery, electric The present invention can also be applied to a double layer capacitor (capacitor), an electric double layer chemical capacitor (capacitor), and the like.
[0044]
【The invention's effect】
The wound battery according to the present invention has a high output by electrically connecting the positive electrode active material sheet of the electrode body to the positive electrode external terminal and the negative electrode active material sheet of the electrode body to the negative electrode external terminal without welding. Even in the case of discharging, it is possible to reduce the voltage drop and improve the performance.
[0045]
Moreover, in the manufacturing method of the wound battery which concerns on this invention, since a welding process is unnecessary, a wound battery can be manufactured very easily.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of the structure of an electrode body of a wound battery according to the present invention.
FIG. 2 is a diagram showing a manufacturing process of an electrode body of a wound battery according to the present invention.
FIG. 3 is a perspective view of a wound battery according to an embodiment of the present invention.
FIG. 4 is a perspective view of a wound battery according to another embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Electrode body 2 Positive electrode active material sheet 2a The other end part 30 of the electrode body in the axial direction The first separator 31 The second separator 4 The negative electrode active material sheet 4a The one end part 5, 5a of the electrode body in the axial direction Negative electrode external terminal B Battery container D Winding battery

Claims

An electrode body in which a positive electrode active material sheet containing a positive electrode active material and a negative electrode active material sheet containing a negative electrode active material are spirally wound through a separator containing an electrolyte, respectively , at both ends in the axial direction of the electrode body A wound battery comprising a positive external terminal disposed oppositely and electrically connected to the positive active material sheet and a negative external terminal electrically connected to the negative active material sheet ,
The electrode body is spirally overlapped with the sheets shifted in the axial direction so that the positive electrode active material sheet protrudes at one end in the axial direction and the negative electrode active material sheet protrudes from the other end, respectively. To be beaten by
The separator is interposed between the positive electrode active material sheet and the negative electrode active material sheet, and a first separator whose one end is bent so as to cover an end opposite to the protruding direction of the negative electrode active material sheet; One of the positive electrode active material sheet and the negative electrode active material sheet is sandwiched between the first separator and the other end is bent so as to cover the end opposite to the protruding direction of the positive electrode active material sheet. A second separator,
The positive electrode external terminal abuts is arranged at one end of the electrode body, contact electrically connected to an end of the positive electrode active material sheet projecting from between the first separator and the second separator And is separated from the end opposite to the protruding direction of the negative electrode active material sheet through one end of the first separator,
The negative electrode external terminal, the is disposed at the other end portion of the electrode body in contact with said first separator and an end of the anode active material sheet which protrudes from between the second separator abutting electrically with the A wound battery characterized in that it is connected and isolated from the end opposite to the protruding direction of the positive electrode active material sheet via the other end of the second separator .

The electrode body is wound battery according to claim 1, further comprising a binding member for binding by winding the outer periphery thereof.

A plurality of the electrode bodies;
The plurality of electrode bodies are arranged in parallel in a container having two surfaces facing each other and constituting the positive external terminal and the negative external terminal ,
The positive electrode external terminal is in contact with and electrically connected to an end of the positive electrode active material sheet of each of the plurality of electrode bodies, and the negative electrode external terminal is connected to the negative electrode active material of each of the plurality of electrode bodies. The wound battery according to claim 1 or 2 , wherein the wound battery is electrically connected in contact with an end portion of the sheet .

The wound battery according to claim 3, wherein the plurality of electrode bodies include a plurality of types of electrode bodies having different charge / discharge characteristics.

It said container is a plurality, the plurality of containers are disposed in series,
Winding battery according to claim 3, wherein that the negative electrode external terminal of positive electrode external terminal and the other container of one of the container facing contacts of the container adjacent to each other.

Winding battery, winding battery according to any one of claims 1 to 5, characterized in that a nickel-hydrogen battery.

A positive electrode active material sheet containing a positive electrode active material, a negative electrode active material sheet containing a negative electrode active material, a first separator interposed between both sheets, and either one of the sheets between the first separators and a second separator sandwiching, wherein the positive electrode active material sheet from between the one end side of the separators are superimposed the state where the from between the other end of the separators negative electrode active material sheet is shifted so as to protrude respectively And bending one end of the first separator so as to cover the end opposite to the protruding direction of the negative electrode active material sheet and covering the end opposite to the protruding direction of the positive electrode active material sheet. A first step of bending the other end of the second separator ;
A second step of forming an electrode body superimposed two sheets and the separators were then wound spirally,
By abutting the one end portion in the axial direction and the positive external terminal of the electrode body, an end of the positive electrode active material sheet which project the positive electrode external terminal from between the first separator and the second separator The negative electrode external terminal protrudes from between the first separator and the second separator by abutting and electrically connecting, and bringing the other end in the axial direction of the electrode body into contact with the negative electrode external terminal. And a third step of electrically connecting the negative electrode active material sheet in contact with the end of the negative electrode active material sheet.

8. The method of manufacturing a wound battery according to claim 7 , wherein the second step further includes a step of binding the wound outer sheets of both the sheets and the separators with a binding member.