JP4091769B2

JP4091769B2 - Square sealed battery

Info

Publication number: JP4091769B2
Application number: JP2002014703A
Authority: JP
Inventors: 弘海加治屋; 昭司唐沢; 正人大西
Original assignee: Panasonic Corp; Toyota Motor Corp; Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Corp; Toyota Motor Corp; Panasonic Holdings Corp
Priority date: 2001-08-06
Filing date: 2002-01-23
Publication date: 2008-05-28
Anticipated expiration: 2022-01-23
Also published as: JP2003123731A

Description

【０００１】
【発明の属する技術分野】
本発明は角形密閉式電池に関し、特に複数の単電池を接続してなる集合型二次電池の内部抵抗の低減を図った角形密閉式電池に関するものである。
【０００２】
【従来の技術】
所要の電力容量が得られるように複数の単電池を接続して成る従来の集合型二次電池は、複数個の個別の直方体状の単電池を、その電槽の幅の広い長側面同士を互いに対向させて重ねるように配置し、両端の単電池の電槽の外側にエンドプレートを配置して拘束バンドにて結束することで一体的に連結し、また各単電池において極板の上端部から上方にリードを引き出して電槽の蓋に装着された端子に接続し、単電池間で端子同士を接続板で接続して構成されている。
【０００３】
そのため、単電池間の接続経路が長くかつ接続箇所が多いために接続部品を含む構成部品による部品抵抗が大きく、この部品抵抗と、正極板と負極板及び電解液による電池反応における反応抵抗との比率が、４０〜５０％：６０〜５０％にも達し、大きな内部抵抗により電池の発熱が大きくなるため、高出力化の実現や寿命特性の向上に対して大きな障害になっていた。また、単電池間の接続構成が複雑で部品点数が多いためにコスト高になるという問題もあった。
【０００４】
そこで、本出願人は、先に図１６、図１７に示すように、複数の単電池２を内蔵した角形密閉式電池１を提案している。３はその角形電槽で、幅の狭い短側面と幅の広い長側面とを有する直方体状の単電池２の電槽４をその短側面を隔壁５として共用して相互に一体的に連接してなる扁平な直方体状に形成され、各電槽４の上面開口は一体の蓋体６にて一体的に閉鎖されている。両端の電槽４の外側の短側面と各電槽４、４間の隔壁５の上部に接続穴７が形成されている。各電槽４内には、矩形状の正極板と負極板をセパレータを介して積層して構成された極板群８が電解液とともに収容され、単電池２が構成されている。極板群８の正極板と負極板は互いに反対側の側部に突出されて正極板と負極板のリード部９ａ、９ｂとされ、それらのリード部９ａ、９ｂの側端縁にはそれぞれ集電板１０ａ、１０ｂが溶接等にて接続されている。
【０００５】
集電板１０ａ、１０ｂの上部には接続穴７内に嵌入する接続突部１１が突設され、隣接する電槽４、４間で正極と負極の集電板１０ａ、１０ｂの接続突部１１を互いに溶接して接続されている。また、両端の電槽４の外側の短側面の接続穴７に正極又は負極の接続端子１２が装着され、その接続突部１３と集電板１０ａ又は１０ｂの接続突部１１とが互いに溶接にて接続されている。かくして、角形電槽３に内蔵された複数の単電池２が直列接続され、両端の接続端子１２、１２間に出力される。
【０００６】
また、蓋体６には各電槽４、４の内圧を均等にする連通路１４や、各電槽４の内部圧力が一定以上になったときに圧力を解放するための安全弁（図示せず）や、適当な単電池２の温度を検出する温度センサを装着するセンサ装着穴１５などが設けられている。
【０００７】
このような構成によると、極板群８における正極板及び負極板からそれぞれのリード部９ａ、９ｂまでの通電経路が短く、かつそのリード部９ａ、９ｂ間が集電板１０ａ、１０を介して角形電槽３内部で接続されているので、上記従来の個別の単電池を接続したものに比べると、接続経路が短くかつ接続箇所が少ないために接続部品を含む構成部品による部品抵抗を小さくでき、その分内部抵抗を低減することができる。
【０００８】
【発明が解決しようとする課題】
ところが、上記図１６、図１７に示すような構成では、正極板及び負極板からそれぞれのリード部９ａ、９ｂ及び集電板１０ａ、１０ｂまでの通電経路は短いが、図１８に矢印で示すように、集電板１０ａ、１０ｂ同士はその上端部の接続突部１１の先端間の１箇所で互いに溶接して接続されているので、接続経路が迂回し、そのため接続経路が長くなり、また１箇所で接続しているので内部抵抗が高くなるという問題がある。
【０００９】
本発明は、上記従来の問題点に鑑み、単電池当たりの内部抵抗をさらに低減して高出力化を実現できる角形密閉式電池を提供することを目的としている。
【００１０】
【課題を解決するための手段】
本発明の角形密閉式電池は、複数の直方体状の電槽を隔壁を介して連接してなる角形電槽と、正極板と負極板をセパレータを介して積層するとともに正極板と負極板の一側部を互いに反対側に突出させてリード部とした極板群と、極板群の両側のリード部に接合した集電体とを備え、各電槽に集電体を接合した極板群を収容した角形密閉式電池において、角形電槽の少なくとも一側壁の各隔壁配設位置に両側の電槽内に連通するように形成した開口を通して導電性接続部材にて隔壁の両側に位置する集電体を接続したものであり、単電池間で隔壁を介して対向する集電体同士を角形電槽の側壁位置で導電性接続部材にて接続しているので、集電体の上端部間で接続している場合に対して通電経路が迂回せず、接続経路が短くなるため、単電池間の接続抵抗を小さくすることができ、その分単電池当たりの内部抵抗をさらに低減して高出力化を実現できる。
【００１１】
また、角形電槽の少なくとも一側壁の各隔壁配設位置に両側の電槽に臨むように開口を設け、開口内に配設した導電性接続板を隔壁の両側に位置する集電体に接続し、かつ導電性接続板を弾性体層を介して角形電槽に密閉接合すると、角形電槽の隔壁や側壁と導電性接続板との間に弾性体層を介在させているので、電槽と導電性接続板の熱膨張差によってそれらの間に剥離隙間が発生するのを防止でき、単電池間での電解液の漏液に防止して液絡が生じる恐れも無くすことができる。
【００１２】
また、弾性体層を、フッ素系ゴムにて構成すると、耐電解液性が高くかつ電池が温度上昇しても必要な耐熱性を有するため、長期にわたって安定した作用が得られ、長期使用に対して高い信頼性が得られる。
【００１３】
また、導電性接続板の隔壁に対向する部分の外周に弾性体層を設けるとともにその外周に角形電槽と同系材質の樹脂層を設けると、角形電槽との間を樹脂成形するにせよ、熱溶着するにせよ、角形電槽側の樹脂と容易かつ確実に一体接合され、弾性体層と角形電槽の樹脂との間での電解液の漏液をさらに確実に防止できる。
【００１４】
また、角形電槽の少なくとも一側壁の各隔壁配設位置に両側の電槽に臨むように開口を設け、開口内に配設した導電性接続板を隔壁の両側に位置する集電体に接続し、かつ角形電槽の構成材料と親和性を有する合成樹脂を導電性接続板に焼き付けて形成した樹脂層を介して角形電槽に密閉接合すると、角形電槽側の樹脂と導電性接続板が焼き付け形成した樹脂層を介して容易かつ確実に一体接合され、電解液の漏液をさらに確実に防止できる。
【００１５】
また、その焼き付けて形成した樹脂層が角形電槽の射出成形温度より低い融点の合成樹脂から成ると、角形電槽とより確実に一体接合され、電解液の漏液をさらに確実に防止できる。
【００１６】
また、導電性接続板を集電体に接続し、樹脂成形にて導電性接続板の周囲と角形電槽の隔壁及び側壁との間を密封接合するとともに開口を密閉し、あるいは導電性接続板を集電体に接続するとともに、樹脂層を角形電槽の隔壁及び側壁の開口縁部に密封接合し、角形電槽の側壁に形成した開口を閉鎖部材にて密閉するとともにこの閉鎖部材と樹脂層の外面とを密封接合することにより、上記構成を実現することができる。
【００１７】
また、角形電槽の少なくとも一側壁の各隔壁配設位置に両側の電槽内に貫通する貫通穴を形成し、隔壁の両側に位置する集電体に貫通穴を通して接続される接続部を両側に有する導電性接続体を設けるとともに貫通穴の周囲と導電性接続体の間にシール材を設け、導電性接続体を角形電槽の側壁に埋設すると、両側の電槽内に貫通穴が貫通し、その周囲と導電性接続体との間でシール材にてシールしているので、電解液の漏液に対する高いシール性が容易に得られる。
【００１８】
また、角形電槽の両端壁及び隔壁の上部に形成された接続穴を介して角形電槽両端の接続端子と集電体及び集電体同士を接続すると、集電体同士をその上部で接続している従来の構成の角形密閉式電池の製造設備をそのまま利用しながら、上記構成の適用により接続抵抗を低減でき、また角形密閉式電池の外部との接続端子が角形電槽の両端壁の上部に配設されるので、他の角形密閉式電池との接続が容易でかつ水冷による冷却機構等を設ける場合の絶縁性の確保が容易である等の効果を奏する。
【００１９】
【発明の実施の形態】
以下、本発明の角形密閉式電池の第１の実施形態について、図１〜図６を参照して説明する。なお、図１６、図１７を参照して説明した従来例と同一の構成要素については、同一の参照符号を付し、主として相違点を説明する。
【００２０】
図１において、本実施形態の角形密閉式電池１における角形電槽３は、幅の狭い短側面と幅の広い長側面とを有する直方体状の複数の電槽４をその短側面を隔壁５として共用して相互に一体的に連接して構成されている。各電槽４にはその両側に集電体１０が接合された極板群８が電解液とともに収容されて単電池２が構成されている。角形電槽３の両端壁及び隔壁５の上部には接続穴７（図１６参照）が形成され、この接続穴７を通して両端の単電池２の集電体１０に接続端子１２が接続されるとともに、隣接する単電池２、２の集電体１０、１０同士が接続されている。図１において、１６は蓋体６に設けられた安全弁である。
【００２１】
極板群８は、複数枚の正極板と複数枚の負極板とを交互に配置するとともに、各正極板に横方向に開口部を有する袋状のセパレータを被せることにより正極板と負極板の間にセパレータを介装した状態で積層して構成され、正極板と負極板の一側部を互いに反対側に突出させて正極と負極のリード部９が設けられている。正極板は、Ｎｉの発泡メタルにリード部９を除いて水酸化ニッケルを充填して構成され、そのリード部９は発泡メタルを加圧して圧縮するとともにその一面にリード板を超音波溶接でシーム溶接して構成されている。また、負極板は、Ｎｉのパンチングメタルにリード部９を除いて水素吸蔵合金を含む負極構成物質を塗着して構成されている。この極板群８の両側のリード部９には集電体１０が接合されている。
【００２２】
角形電槽３の一方の側壁２０には、図２〜図５に示すように、各隔壁５の配設位置に、１又は複数の開口２１が両側の電槽４に臨むように形成されている。開口２１の幅は、隔壁５の両側の集電体１０の側縁間にわたる幅とされ、上下方向には適当な長さ寸法に設定されている。また、開口２１の部分では隔壁５にも同じ上下長さ寸法で、適当な深さ寸法の切欠２２が形成されている。
【００２３】
開口２１内には、導電性接続板２３が収容配置され、その両側部がそれぞれ集電体１０に溶接２４にて接合され、一方の単電池２の集電体１０からこの導電性接続板２３を通って他方の単電池２の集電体１０に通電されるように構成されている。導電性接続板２３は鋼板にニッケルメッキを施したものが、耐電解液性を有しかつ安価に構成できて好適である。
【００２４】
導電性接続板２３は、図３に示すように、幅方向の両側部から上下方向にそれぞれ突出部２３ａを突出させて全体形状が略Ｈ形に形成され、かつ全体が開口２１に丁度嵌合する大きさに形成されている。この導電性接続板２３の幅方向の中央部の外周にはフッ素系ゴムやその他の耐熱・耐電解液性のゴム材料から成る環状の弾性体層２５が焼き付け固着され、さらにその外周に角形電槽３と同系の合成樹脂から成る環状の樹脂層２６が形成されている。この樹脂層２６は射出成形にて形成され、その射出圧力によって弾性体層２５は圧縮された状態となり、必要なシール圧が発生されている。
【００２５】
また、導電性接続板２３の上下方向中央部の両側に切欠２７が形成され、その上下の計４箇所に溶接２４を確実に行うため集電体１０に圧接させる溶接突部２８が突出形成されている。切欠２７は、導電性接続板２３の各溶接突部２８位置に溶接電極を押し付けて溶接した時に、溶接電流が導電性接続板２３の一方の溶接突部２８から集電体１０を通って他方の溶接突部２８に確実に流れるように設けられている。なお、溶接突部２８の形状は、図示例のような円形突部に限らず、断面山形の線状や円環状の突条などの任意の形状にでき、また溶接突部２８の数も任意に選択できる。
【００２６】
以上のように開口２１に導電性接続板２３を挿入配置し、導電性接続板２３と両側の集電体１０を溶接２４にて接合した後、角形電槽３の側壁２０に開口２１を覆うように射出成形金型３０を配設して加圧密接させ、開口２１を密封閉鎖するとともに隔壁５の切欠２２と樹脂層２６の外周との間の隙間を充填するように密封樹脂部３１が射出成形されている。なお、極板群８の開口２１形成側の側面の開口２１の近傍部分には遮熱シート２９が配設されている。
【００２７】
以上の構成においては、単電池２、２間で隔壁５を介して対向する集電体１０、１０同士を導電性接続板２３にて接続しているので、集電体１０の上端部間のみを接続突部１１、１１同士を接合して接続している場合に対して、集電体１０の側部でも１又は複数箇所で導電性接続板２３にて接続されているので、通電経路が迂回せず、接続経路が短くなるため、単電池２、２間の接続抵抗を小さくすることができ、その分単電池２当たりの内部抵抗をさらに低減して高出力化を実現できる。
【００２８】
また、角形電槽３の側壁２０や隔壁５と導電性接続板２３との間に弾性体層２５が介在されているので、角形電槽３と導電性接続板２３の熱膨張差によってそれらの間に剥離隙間が発生するのを防止できる。したがって、単電池２、２間での電解液の漏液を防止して液絡が生じる恐れも無くすことができる。特に、弾性体層２５をフッ素系ゴムにて構成すると、耐熱性及び耐電解液性が高く、電池が温度上昇しても必要な耐熱性を有するため、長期にわたって安定した作用が得られ、長期使用に対して高い信頼性が得られる。また、導電性接続板２３の隔壁５に対向する部分の外周に弾性体層２５を設けるとともにその外周に角形電槽３と同系材質の樹脂層２６を設けているので、角形電槽３側の樹脂と容易かつ確実に一体接合され、弾性体層２５と角形電槽３の樹脂との間での電解液の漏液をさらに確実に防止できる。
【００２９】
また、本実施形態では、角形電槽３の両端壁及び隔壁５の上部に形成された接続穴７を介して角形電槽３の両端の接続端子１２と集電体１０及び各隔壁５両側の集電体１０、１０同士を接続しているので、従来の構成の角形密閉式電池１の製造設備をそのまま利用しながら、上記構成の適用により接続抵抗を低減でき、また角形密閉式電池１の外部との接続端子１２が角形電槽３の両端壁の上部に配設されているので、他の角形密閉式電池１との接続が容易でかつ水冷による冷却機構等を設ける場合の絶縁性の確保が容易である等の効果を奏する。
【００３０】
なお、図示例では導電性接続板２３の外周の弾性体層２５の外周に樹脂層２６を設けた例を示したが、この樹脂層２６は必ずしも設けなくてもよい。
【００３１】
また、以上の説明では、角形電槽３の一方の側壁２０にのみ開口２１を形成して導電性接続板２３にて単電池２、２間を接続する例を示したが、図６に示すように、角形電槽３の両方の側壁２０に互いに対向するように開口２１を形成し、隔壁５の両側の集電体１０、１０をその両側で導電性接続板２３にて接続し、角形電槽３の両側から射出成形金型３０を押し付けて射出成形にて密封樹脂部３１を形成してもよい。こうすると、集電体１０、１０同士を両側で接続するので、より接続抵抗の低減化を図ることができるとともに、射出成形時に角形電槽３及び内部の集電体１０及び極板群８に両側から均等に加圧力が作用するので、極板群８に対する片方からの荷重の作用やそれに伴う移動等により悪影響が生じるのを防止できる。
【００３２】
次に、本発明の第２の実施形態の角形密閉式電池について、図７〜図９を参照して説明する。なお、以下の実施形態の説明においては、先行する実施形態と同一の構成要素については、同一の参照符号を付して説明を省略し、相違点のみを説明する。
【００３３】
上記実施形態では、導電性接続板２３を溶接した後、樹脂成形によって開口２１を密封するようにした例を示したが、本実施形態では、導電性接続板２３を集電体１０、１０に溶接接続するとともに、樹脂層２６を角形電槽３の隔壁５及び開口２１の開口縁部に密封接合し、さらに角形電槽３の側壁２０に形成した開口２１を閉鎖部材３２にて密閉するとともにこの閉鎖部材３２と樹脂層２６の外面とを密封接合している。
【００３４】
詳細に説明すると、開口２１は矩形状で、導電性接続板２３は両側に切欠２７と溶接突部２８が設けられた全体形状が開口２１よりも小さい矩形状である。この導電性接続板２３の幅方向中央部外周に弾性体層２５が設けられ、その外周に樹脂層２６が設けられている。隔壁５に形成された切欠２２は外側に向けて広がる台形状で、かつ開口２１の切欠２２に対向する部分の縁部は、台形状の切欠２２の斜面に連続する傾斜延長面３３を形成するように三角形状に切欠かれている。樹脂層２６は、その外形が切欠２２の端面及び傾斜延長面３３に沿うとともにその外側面が側壁２０の外面と面一になるような台形状に成形されている。
【００３５】
そして、樹脂層２６の台形外面と切欠２２の端面及び傾斜延長面３３とが熱溶着ライン３４にて密封状態で一体接合されている。また、閉鎖部材３２を開口２１及びその周囲を覆うように配置し、この閉鎖部材３２と側壁２０の外面及び樹脂層２６の外側面とが熱溶着ライン３５にて密封状態で一体接合されている。
【００３６】
本実施形態においても、単電池２、２間で隔壁５を介して対向する集電体１０、１０同士を導電性接続板２３にて接続しているので、単電池２、２間の接続抵抗が小さくなって単電池２当たりの内部抵抗をさらに低減して高出力化を実現できる。また、その導電性接続板２３の隔壁５に対向する部分の外周に弾性体層２５を設けるとともにその外周に角形電槽３と同系材質の樹脂層２６を設けているので、角形電槽３側の樹脂と樹脂層２６を熱溶着することにより、密封状態を確保しながら容易かつ確実に一体接合され、弾性体層２５と角形電槽３の樹脂との間での電解液の漏液を確実に防止できる。
【００３７】
次に、本発明の第３の実施形態の角形密閉式電池について、図１０、図１１を参照して説明する。
【００３８】
上記実施形態では、導電性接続板２３の幅方向の中央部の外周に弾性体層２５を焼き付け固着し、その外周に角形電槽３と同系の合成樹脂から成る環状の樹脂層２６を設けた例を示したが、本実施形態では、導電性接続板２３の幅方向の中央部の外周に、角形電槽３の構成材料と親和性を有する合成樹脂を焼き付け形成した焼付樹脂層３６を設けている。この焼付樹脂層３６は角形電槽３を構成している合成樹脂の射出成形温度より低い融点の合成樹脂の粉体を導電性接続板２３の該当範囲に添着した状態で加熱炉に投入して焼き付け固着して構成するのが好適である。例えば、角形電槽３がポリプロピレンやポリエチレンやそれらのアロイから成る場合、エポキシ樹脂の粉体を焼き付け塗工するのが好適である。
【００３９】
このような焼付樹脂層３６を設けた導電性接続板２３を開口２１に配置し、隔壁５の両側の集電体１０と溶接２４にて接合した後、開口２１を覆うように射出成形金型３０を配設し、開口２１を密封閉鎖するとともに隔壁５の切欠２２と焼付樹脂層３６の外周との間の隙間を充填するように密封樹脂部３１を射出成形することにより、角形電槽３と導電性接続板２３の間が、導電性接続板２３に一体的に密着された焼付樹脂層３６とそれに一体的に密着して形成される密封樹脂部３１を介して接合され、電槽４、４間を確実にシールするとともに開口２１を完全に封止することができる。
【００４０】
本実施形態によれば、角形電槽３側の樹脂と導電性接続板２３が、焼付樹脂層３６を介して容易かつ確実に一体的に密着された状態で接合されるので、電解液の漏液をさらに確実に防止できる。
【００４１】
なお、図示例では、第１の実施形態と同様に射出成形にて形成した密封樹脂部３１にて開口２１を密封した例を示したが、第２の実施形態と同様に、焼付樹脂層３６を角形電槽３の隔壁５に密封接合し、さらに開口２１を閉鎖部材３２にて密閉するとともにこの閉鎖部材３２と焼付樹脂層３６の外面とを密封接合するようにしてもよい。
【００４２】
次に、本発明の第４の実施形態の角形密閉式電池について、図１２〜図１５を参照して説明する。
【００４３】
上記各実施形態では、角形電槽３の側壁２０に隔壁５の両側の電槽４に臨む矩形状の開口２１を形成し、その開口２１内に導電性接続板２３を配置して集電体１０に接合した後、密封樹脂部３１や閉鎖部材３２にて密封した例を示したが、本実施形態では、図１２、図１３に示すように、角形電槽３の側壁２０の各隔壁５の配設位置に、両側の電槽４にわたる幅の凹部３７を形成するとともに、その凹部３７の底面から両側の電槽４内に貫通する貫通穴３８を形成し、貫通穴３８を通して隔壁５の両側に位置する集電体１０に接続される接続部３９を両側に有する導電性接続体４０を凹部３７内に配置し、接続部３９と集電体１０を溶接４１にて接合している。導電性接続体４０は鋼板にニッケルメッキを施したものが、耐電解液性を有しかつ安価に構成できて好適である。
【００４４】
接続部３９は丸軸状の突軸にて構成されてその外周にシール材としてのＯリング４２が装着され、接続部３９を集電体１０に接合した状態でＯリング４２が凹部３７の底面と導電性接続体４０の間で圧縮されて貫通穴３８が密閉されている。凹部３７内は導電性接続体４０を埋設した状態で封止樹脂４３が充填されている。
【００４５】
以上の構成における接合工程を説明すると、図１２、図１３の図示例では、角形電槽３の両側の側壁２０に凹部３７及び貫通穴３８を形成し、接続部３９にＯリング４２を装着した導電性接続体４０をそれぞれ凹部３７に配置してその接続部３９を貫通穴３８に挿入し、次に図１２に仮想線で示し、図１３に実線で示すように、隔壁５両側の集電体１０の内の一方の集電体１０の両側に当接する接続部３９、３９の背部に溶接電極４４を当接させて加圧し、その状態で抵抗溶接機４５にて溶接電流を流すことによってこの集電体１０の両側に導電性接続体４０の接続部３９を溶接４１にて接合し、次に他方の集電体１０の両側にも同様にして接続部３９、３９を溶接４１にて接合することで、両側の集電体１０をその両側部で導電性接続体４０を介して接続する。その後、側壁２０に射出金型（図示せず）を押し当てて封止樹脂４３を射出成形することによって、接合が完了する。
【００４６】
以上の説明では、角形電槽３の両側の側壁２０に凹部３７を形成して導電性接続体４０を配設し、集電体１０、１０をその両側で接続しているが、図１４、図１５に示すように、集電体１０、１０をその一側でのみ接続してもよい。その場合、一方の側壁にのみ凹部３７を形成し、その凹部３７内の上部と下部にそれぞれ隔壁５の両側の電槽４内に貫通するように貫通穴３８を形成し、隔壁５両側の貫通穴３８に両側の接続部３９が貫通してそれぞれ集電体１０に当接する導電性接続体４０を上下に一対配置し、隔壁５の一側の集電体１０に当接している上部と下部の接続部３９、３９の背部に溶接電極４４を押し当てて抵抗溶接機４５にて溶接電流を流すことで一側の集電体１０に上下の導電性接続体４０を溶接４１にて接続し、次に同様に隔壁５の他側の集電体１０に当接している上部と下部の接続部３９、３９の背部に溶接電極４４を押し当てて抵抗溶接機４５にて溶接電流を流すことで他側の集電体１０に上下の導電性接続体４０を溶接４１にて接続する。かくして、隔壁５両側の集電体１０を上下一対の導電性接続体４０を介して接続することができる。
【００４７】
なお、溶接電極４４には、導電性接続体４０を吸着保持する吸引通路４４ａを有するものを用いると作業性が良くなる。また、図示例では上下の導電性接続体４０が完全に別体のものを示したが、電流の通り難い細幅部を介して一体的に連結して一体化した単一の導電性接続体を用いることもできる。また、接続部３９として丸軸状の突軸からなるものを例示したが、断面矩形状の部材を折り曲げ形成して構成しても良い。しかし、その場合信頼性の高いシールを得るのが困難である。
【００４８】
本実施形態によれば、隔壁５両側の電槽４、４内に貫通するように貫通穴３８を形成し、その周囲と導電性接続体４０との間にＯリング４２などのシール材を介装してシールしているので、電解液の漏液に対して高いシール性を容易に得ることができる。
【００４９】
以上の各実施形態の説明では、導電性接続板２３や導電性接続体４０に溶接電極を当て、導電性接続板２３や導電性接続体４０と集電体１０との間に溶接電流を流して抵抗溶接した例を示したが、電子ビームやレーザビームを照射して局部を加熱溶融させて溶接しても良い。しかし、抵抗溶接の方が周囲に対する熱影響が小さくて済むので好ましい。また、導電性接続板２３や導電性接続体４０や集電体１０の接続部にロウ材を設けておいてロウ付けするようにしてもよく、また導電性接着材等で接着接合するようにしてもよい。
【００５０】
【発明の効果】
本発明の角形密閉式電池によれば、以上の説明から明らかなように、角形電槽の少なくとも一側壁の各隔壁配設位置に両側の電槽内に連通するように形成した開口を通して導電性接続部材にて隔壁の両側に位置する集電体を接続したので、単電池間で隔壁を介して対向する集電体同士を角形電槽の側壁位置で導電性接続部材にて接続でき、接続経路が短くなるため、単電池間の接続抵抗を小さくすることができ、その分単電池当たりの内部抵抗をさらに低減して高出力化を実現できる。
【００５１】
また、角形電槽の少なくとも一側壁の各隔壁配設位置に両側の電槽に臨むように開口を設け、開口内に配設した導電性接続板を隔壁の両側に位置する集電体に接続し、かつ導電性接続板を弾性体層を介して角形電槽に密閉接合すると、角形電槽の隔壁や側壁と導電性接続板との間に弾性体層を介在させているので、電槽と導電性接続板の熱膨張差によってそれらの間に剥離隙間が発生するのを防止でき、単電池間での電解液の漏液を防止して液絡が生じる恐れも無くすことができる。
【００５２】
また、弾性体層を、フッ素系ゴムにて構成すると、耐電解液性が高くかつ電池が温度上昇しても必要な耐熱性を有するため、長期にわたって安定した作用が得られ、長期使用に対して高い信頼性が得られる。
【００５３】
また、導電性接続板の隔壁に対向する部分の外周に弾性体層を設けるとともにその外周に角形電槽と同系材質の樹脂層を設けると、角形電槽側の樹脂と容易かつ確実に一体接合され、弾性体層と角形電槽の樹脂との間での電解液の漏液をさらに確実に防止できる。
【００５４】
また、角形電槽の少なくとも一側壁の各隔壁配設位置に両側の電槽に臨むように開口を設け、開口内に配設した導電性接続板を隔壁の両側に位置する集電体に接続し、かつ角形電槽の構成材料と親和性を有する合成樹脂を導電性接続板に焼き付けて形成した樹脂層を介して角形電槽に密閉接合すると、角形電槽側の樹脂と導電性接続板が焼き付け形成した樹脂層を介して容易かつ確実に一体接合され、電解液の漏液を確実に防止できる。
【００５５】
また、その焼き付け形成する樹脂層を角形電槽の射出成形温度より低い融点の合成樹脂にて構成すると、より確実に一体接合され、電解液の漏液をさらに確実に防止できる。
【００５６】
また、導電性接続板を集電体に接続し、樹脂成形にて導電性接続板の周囲と角形電槽の隔壁及び側壁との間を密封接合するとともに開口を密閉すると、樹脂成形にて上記構成を実現してその効果を奏することができる。
【００５７】
また、導電性接続板を集電体に接続するとともに、樹脂層を角形電槽の隔壁及び側壁の開口縁部に密封接合し、角形電槽の側壁に形成した開口を閉鎖部材にて密閉するとともにこの閉鎖部材と樹脂層の外面とを密封接合すると、樹脂同士の熱溶着や接着等にて接合することで上記構成を実現してその効果を奏することができる。
【００５８】
また、角形電槽の少なくとも一側壁の各隔壁配設位置に両側の電槽内に貫通する貫通穴を形成し、隔壁の両側に位置する集電体に貫通穴を通して接続される接続部を両側に有する導電性接続体を設けるとともに貫通穴の周囲と導電性接続体の間にシール材を設け、導電性接続体を角形電槽の側壁に埋設すると、両側の電槽内に貫通穴が貫通し、その周囲と導電性接続体との間でシール材にてシールしているので、電解液の漏液に対する高いシール性が容易に得られる。
【００５９】
また、角形電槽の両端壁及び隔壁の上部に形成された接続穴を介して角形電槽両端の接続端子と集電体及び集電体同士を接続すると、集電体同士をその上部で接続している従来の構成の角形密閉式電池の製造設備をそのまま利用しながら、上記構成の適用により接続抵抗を低減でき、また角形密閉式電池の外部との接続端子が角形電槽の両端壁の上部に配設されるので、他の角形密閉式電池との接続が容易でかつ水冷による冷却機構等を設ける場合の絶縁性の確保が容易である等の効果を奏する。
【図面の簡単な説明】
【図１】本発明の角形密閉式電池の第１の実施形態をその角形電槽の一部を破断して示した全体斜視図である。
【図２】同実施形態における要部の横断平面図である。
【図３】同実施形態における導電性接続板の斜視図である。
【図４】図２のＡ−Ａ矢視断面図である。
【図５】図４のＢ−Ｂ矢視図である。
【図６】同実施形態の変形例における要部の横断平面図である。
【図７】本発明の角形密閉式電池の第２の実施形態における要部の横断平面図である。
【図８】図７のＣ−Ｃ矢視断面図である。
【図９】図８のＤ−Ｄ矢視図である。
【図１０】本発明の角形密閉式電池の第３の実施形態における要部の横断平面図である。
【図１１】同実施形態における導電性接続板の斜視図である。
【図１２】本発明の角形密閉式電池の第４の実施形態における要部の横断平面図である。
【図１３】同実施形態の要部の拡大横断平面図である。
【図１４】同実施形態の変形例における要部の横断平面図である。
【図１５】同変形例における導電性接続部材と集電体の接合工程を示す、図１４のＥ−Ｅ矢視縦断側面図である。
【図１６】従来例の角形密閉式電池の部分縦断正面図である。
【図１７】同従来例における電槽の一部を破断して示した斜視図である。
【図１８】同従来例における通電経路の説明図である。
【符号の説明】
１角形密閉式電池
３角形電槽
４電槽
５隔壁
８極板群
９（９ａ、９ｂ）リード部
１０集電体
１２接続端子
２０側壁
２１開口
２３導電性接続板
２５弾性体層
２６樹脂層
３１密封樹脂部
３２閉鎖部材
３４熱溶着ライン
３５熱溶着ライン
３６焼付樹脂層
３８貫通穴
３９接続部
４０導電性接続体
４２Ｏリング（シール材）
４３封止樹脂[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rectangular sealed battery, and more particularly to a rectangular sealed battery in which the internal resistance of an assembled secondary battery formed by connecting a plurality of single cells is reduced.
[0002]
[Prior art]
A conventional collective secondary battery in which a plurality of unit cells are connected so as to obtain a required power capacity is obtained by connecting a plurality of individual rectangular parallelepiped unit cells to a wide long side of the battery case. They are arranged so as to face each other, and are connected together by arranging end plates outside the battery case of the unit cells at both ends and binding them with a restraining band, and in each unit cell, the upper end of the electrode plate The lead is drawn upward from the terminal and connected to a terminal mounted on the lid of the battery case, and the terminals are connected to each other by a connecting plate between the single cells.
[0003]
Therefore, since the connection path between the single cells is long and there are many connection parts, the component resistance due to the component parts including the connection parts is large. The ratio reached 40 to 50%: 60 to 50%, and the heat generation of the battery increased due to the large internal resistance, which was a major obstacle to realizing high output and improving life characteristics. In addition, there is a problem in that the connection configuration between single cells is complicated and the number of parts is large, resulting in an increase in cost.
[0004]
Therefore, the present applicant has previously proposed a rectangular sealed battery 1 incorporating a plurality of single cells 2 as shown in FIGS. 3 is a rectangular battery case, and the battery case 4 of the rectangular parallelepiped unit cell 2 having a narrow short side face and a wide long side face is commonly connected to each other by sharing the short side face as a partition wall 5. The upper surface opening of each battery case 4 is integrally closed by an integral lid body 6. A connection hole 7 is formed in the short side surface outside the battery case 4 at both ends and the upper part of the partition wall 5 between the battery cases 4 and 4. In each battery case 4, an electrode plate group 8 formed by laminating a rectangular positive electrode plate and a negative electrode plate via a separator is accommodated together with an electrolytic solution, and a single battery 2 is configured. The positive electrode plate and the negative electrode plate of the electrode plate group 8 are projected to the opposite side portions to form lead portions 9a and 9b of the positive electrode plate and the negative electrode plate, and are gathered at the side edges of the lead portions 9a and 9b, respectively. The electric plates 10a and 10b are connected by welding or the like.
[0005]
A connection protrusion 11 that fits into the connection hole 7 protrudes from the upper part of the current collector plates 10 a and 10 b, and the connection protrusion 11 of the positive and negative current collector plates 10 a and 10 b between the adjacent battery cases 4 and 4. Are connected to each other by welding. Moreover, the positive or negative connection terminal 12 is mounted in the connection hole 7 on the short side surface outside the battery case 4 at both ends, and the connection protrusion 13 and the connection protrusion 11 of the current collector plate 10a or 10b are welded to each other. Connected. Thus, the plurality of single cells 2 built in the rectangular battery case 3 are connected in series and output between the connection terminals 12 and 12 at both ends.
[0006]
Further, the lid 6 has a communication passage 14 that equalizes the internal pressure of each battery case 4, 4 and a safety valve (not shown) for releasing the pressure when the internal pressure of each battery case 4 exceeds a certain level. ), A sensor mounting hole 15 for mounting a temperature sensor for detecting the temperature of an appropriate unit cell 2 and the like.
[0007]
According to such a configuration, the energization path from the positive electrode plate and the negative electrode plate to the respective lead portions 9a and 9b in the electrode plate group 8 is short, and between the lead portions 9a and 9b via the current collecting plates 10a and 10 Since it is connected inside the rectangular battery case 3, the resistance of the component parts including the connection parts can be reduced because the connection path is short and the number of connection points is short compared to the conventional individual cell connected. Therefore, the internal resistance can be reduced accordingly.
[0008]
[Problems to be solved by the invention]
However, in the configuration shown in FIGS. 16 and 17, the energization paths from the positive electrode plate and the negative electrode plate to the lead portions 9a and 9b and the current collector plates 10a and 10b are short, but as shown by arrows in FIG. In addition, since the current collector plates 10a and 10b are connected to each other at one point between the tips of the connection protrusions 11 at the upper end thereof, the connection path is detoured, so that the connection path becomes longer and 1 There is a problem that the internal resistance becomes high because the connection is made at a point.
[0009]
The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a rectangular sealed battery that can further reduce the internal resistance per unit cell and realize high output.
[0010]
[Means for Solving the Problems]
The rectangular sealed battery of the present invention includes a rectangular battery case in which a plurality of rectangular battery cases are connected via a partition wall, a positive electrode plate and a negative electrode plate stacked via a separator, and a positive electrode plate and a negative electrode plate. An electrode plate group comprising electrode plates having lead portions protruding from opposite sides and current collectors joined to the lead portions on both sides of the electrode plate group, and current collectors joined to each battery case In a rectangular sealed battery containing a battery, a conductive connecting member is disposed on both sides of the partition wall through an opening formed so as to communicate with the inside of the battery case on both sides of the partition wall on at least one side wall of the rectangular battery case. The current collectors are connected, and the current collectors facing each other through the partition walls between the single cells are connected by the conductive connection member at the side wall position of the rectangular battery case, so between the upper ends of the current collectors Since the energization path is not detoured and the connection path is shortened compared to Of it is possible to reduce the connection resistance can be realized further reduced to high output internal resistance per correspondingly single cell.
[0011]
In addition, an opening is provided at each partition wall installation position on at least one side wall of the rectangular battery case so as to face the battery tanks on both sides, and the conductive connection plates disposed in the opening are connected to the current collectors located on both sides of the partition wall And when the conductive connecting plate is hermetically joined to the rectangular battery case through the elastic layer, the elastic layer is interposed between the partition wall or the side wall of the rectangular battery case and the conductive connecting plate. It is possible to prevent a separation gap between them due to the difference in thermal expansion between the conductive connecting plate and the conductive connecting plate, and to prevent leakage of the electrolyte between the single cells, thereby eliminating the possibility of a liquid junction.
[0012]
In addition, if the elastic layer is made of fluorine-based rubber, it has high electrolyte resistance and the necessary heat resistance even when the battery temperature rises. High reliability.
[0013]
In addition, if an elastic body layer is provided on the outer periphery of the portion facing the partition wall of the conductive connection plate and a resin layer of a similar material to the rectangular battery case is provided on the outer periphery, the resin is molded between the rectangular battery case, Even if heat welding is performed, it is easily and reliably integrally joined with the resin on the rectangular battery case side, and leakage of the electrolyte solution between the elastic body layer and the resin in the rectangular battery case can be further reliably prevented.
[0014]
In addition, an opening is provided at each partition wall installation position on at least one side wall of the rectangular battery case so as to face the battery tanks on both sides, and the conductive connection plates disposed in the opening are connected to the current collectors located on both sides of the partition wall In addition, when the synthetic resin having affinity with the constituent material of the rectangular battery case is baked on the conductive connection plate and sealed and bonded to the rectangular battery case, the resin on the square battery case and the conductive connection plate are obtained. Can be easily and reliably integrally joined through the resin layer formed by baking, and the leakage of the electrolyte can be further reliably prevented.
[0015]
Further, when the resin layer formed by baking is made of a synthetic resin having a melting point lower than the injection molding temperature of the rectangular battery case, the resin layer is more reliably integrally joined to the rectangular battery case, and the leakage of the electrolyte can be further reliably prevented.
[0016]
In addition, the conductive connecting plate is connected to the current collector, and the periphery of the conductive connecting plate and the partition wall and the side wall of the rectangular battery case are sealed and joined by resin molding and the opening is sealed, or the conductive connecting plate Is connected to the current collector, and the resin layer is hermetically bonded to the partition wall and the opening edge of the side wall of the rectangular battery case, and the opening formed on the side wall of the square battery case is sealed with a closing member and the closing member and the resin are sealed. The above-described configuration can be realized by hermetically joining the outer surface of the layer.
[0017]
Also, through holes penetrating into the battery case on both sides are formed at each partition wall installation position on at least one side wall of the rectangular battery case, and connecting portions connected to the current collectors located on both sides of the partition wall through the through holes are provided on both sides. If the conductive connector is embedded in the side wall of the rectangular battery case, the through hole penetrates into the battery case on both sides. And since it seals with the sealing material between the circumference | surroundings and the electroconductive connection body, the high sealing performance with respect to the electrolyte leakage is easily obtained.
[0018]
In addition, when the connection terminals, current collectors and current collectors at both ends of the square battery case are connected via the connection holes formed at both ends of the square battery case and the upper part of the partition wall, the current collectors are connected at the upper part. The connection resistance can be reduced by applying the above configuration while using the manufacturing facilities of the rectangular sealed battery with the conventional configuration as it is, and the connection terminals with the outside of the rectangular sealed battery are connected to both end walls of the rectangular battery case. Since it is disposed at the top, it is easy to connect to other rectangular sealed batteries, and it is easy to ensure insulation when providing a cooling mechanism or the like by water cooling.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a first embodiment of a square sealed battery of the present invention will be described with reference to FIGS. In addition, about the component same as the prior art example demonstrated with reference to FIG. 16, FIG. 17, the same referential mark is attached | subjected and a difference is mainly demonstrated.
[0020]
In FIG. 1, a rectangular battery case 3 in the rectangular sealed battery 1 of the present embodiment includes a plurality of rectangular parallelepiped battery cases 4 having a narrow short side surface and a wide long side surface. They are shared and integrally connected to each other. In each battery case 4, an electrode plate group 8 having current collectors 10 bonded to both sides thereof is accommodated together with an electrolytic solution to constitute a unit cell 2. Connection holes 7 (see FIG. 16) are formed in the both end walls of the rectangular battery case 3 and the upper part of the partition wall 5, and the connection terminals 12 are connected to the current collectors 10 of the unit cells 2 at both ends through the connection holes 7. The current collectors 10 and 10 of the adjacent unit cells 2 and 2 are connected to each other. In FIG. 1, 16 is a safety valve provided on the lid 6.
[0021]
The electrode group 8 includes a plurality of positive plates and a plurality of negative plates arranged alternately, and each positive plate is covered with a bag-like separator having an opening in the lateral direction, thereby forming a gap between the positive plate and the negative plate. A positive electrode plate and a negative electrode lead portion 9 are provided by laminating one side of the positive electrode plate and the negative electrode plate opposite to each other. The positive electrode plate is configured by filling nickel foam metal with nickel hydroxide except for the lead portion 9, and the lead portion 9 pressurizes and compresses the foam metal and seams the lead plate on one surface thereof by ultrasonic welding. It is constructed by welding. The negative electrode plate is configured by applying a negative electrode constituent material containing a hydrogen storage alloy to Ni punching metal except for the lead portion 9. Current collectors 10 are joined to the lead portions 9 on both sides of the electrode plate group 8.
[0022]
As shown in FIG. 2 to FIG. 5, one or a plurality of openings 21 are formed on one side wall 20 of the rectangular battery case 3 so as to face the battery case 4 on both sides. Yes. The width of the opening 21 is a width extending between the side edges of the current collector 10 on both sides of the partition wall 5 and is set to an appropriate length dimension in the vertical direction. Further, in the opening 21, the partition wall 5 is also formed with a notch 22 having the same vertical length and an appropriate depth.
[0023]
A conductive connecting plate 23 is accommodated in the opening 21, and both side portions thereof are joined to the current collector 10 by welding 24, and the conductive connecting plate 23 is connected from the current collector 10 of one unit cell 2. The current collector 10 of the other unit cell 2 is energized through. As the conductive connecting plate 23, a steel plate that is nickel-plated is suitable because it has resistance to electrolyte and can be constructed at low cost.
[0024]
As shown in FIG. 3, the conductive connecting plate 23 is formed in a substantially H shape by projecting the projecting portions 23 a in the vertical direction from both sides in the width direction, and the whole is just fitted into the opening 21. It is formed in the size to be. An annular elastic layer 25 made of a fluorine-based rubber or other heat-resistant / electrolyte-resistant rubber material is baked and fixed to the outer periphery of the central portion in the width direction of the conductive connecting plate 23. Further, a rectangular electric material is attached to the outer periphery thereof. An annular resin layer 26 made of a synthetic resin similar to the tank 3 is formed. The resin layer 26 is formed by injection molding. The elastic body layer 25 is compressed by the injection pressure, and a necessary sealing pressure is generated.
[0025]
In addition, notches 27 are formed on both sides of the central portion of the conductive connecting plate 23 in the vertical direction, and welding protrusions 28 are formed so as to be pressed against the current collector 10 in order to ensure welding 24 at a total of four locations above and below the cutout 27. ing. When the notch 27 is welded by pressing the welding electrode to the position of each welding projection 28 of the conductive connection plate 23, the welding current passes from the one welding projection 28 of the conductive connection plate 23 through the current collector 10 to the other. It is provided so as to flow reliably to the welding projection 28. In addition, the shape of the welding protrusion 28 is not limited to the circular protrusion as shown in the illustrated example, but can be any shape such as a linear cross section or an annular protrusion, and the number of the welding protrusions 28 is also arbitrary. Can be selected.
[0026]
As described above, the conductive connection plate 23 is inserted and disposed in the opening 21, and the conductive connection plate 23 and the current collectors 10 on both sides are joined by welding 24, and then the opening 21 is covered on the side wall 20 of the rectangular battery case 3. In this way, the injection mold 30 is disposed and press-contacted, the opening 21 is hermetically closed, and the sealing resin portion 31 is sealed so as to fill a gap between the notch 22 of the partition wall 5 and the outer periphery of the resin layer 26. It is injection molded. A heat shield sheet 29 is disposed in the vicinity of the opening 21 on the side surface of the electrode group 8 on the side where the opening 21 is formed.
[0027]
In the above configuration, the current collectors 10 and 10 facing each other between the single cells 2 and 2 via the partition wall 5 are connected to each other by the conductive connection plate 23, so that only between the upper ends of the current collectors 10. Are connected by the conductive connection plate 23 at one or a plurality of locations on the side of the current collector 10. Since the connection path is shortened without detouring, the connection resistance between the single cells 2 and 2 can be reduced, and the internal resistance per single cell 2 can be further reduced, and higher output can be realized.
[0028]
In addition, since the elastic body layer 25 is interposed between the side wall 20 or the partition wall 5 of the rectangular battery case 3 and the conductive connection plate 23, the thermal expansion difference between the rectangular battery case 3 and the conductive connection plate 23 causes the difference in thermal expansion between them. It is possible to prevent the separation gap from occurring between them. Therefore, it is possible to prevent the leakage of the electrolyte solution between the single cells 2 and 2 and eliminate the possibility of a liquid junction. In particular, when the elastic body layer 25 is made of a fluorinated rubber, the heat resistance and the electrolytic solution resistance are high, and the necessary heat resistance is obtained even when the battery temperature rises. High reliability is obtained for use. In addition, the elastic body layer 25 is provided on the outer periphery of the portion of the conductive connecting plate 23 facing the partition wall 5 and the resin layer 26 of the same material as the rectangular battery case 3 is provided on the outer periphery. The resin is easily and reliably integrally joined, and the leakage of the electrolyte solution between the elastic body layer 25 and the resin of the rectangular battery case 3 can be further reliably prevented.
[0029]
Further, in the present embodiment, the connection terminals 12 and the current collectors 10 at both ends of the square battery case 3 and the both sides of each partition wall 5 are connected to both end walls of the square battery case 3 and the connection holes 7 formed in the upper part of the partition wall 5. Since the current collectors 10 and 10 are connected to each other, the connection resistance can be reduced by applying the above configuration while using the manufacturing facility of the rectangular sealed battery 1 having the conventional configuration as it is. Since the connection terminal 12 to the outside is disposed on the upper part of both end walls of the rectangular battery case 3, it is easy to connect to other rectangular sealed battery 1 and has an insulating property when a cooling mechanism or the like by water cooling is provided. There are effects such as easy securing.
[0030]
In the illustrated example, the resin layer 26 is provided on the outer periphery of the elastic body layer 25 on the outer periphery of the conductive connection plate 23. However, the resin layer 26 is not necessarily provided.
[0031]
Moreover, in the above description, although the example which formed the opening 21 only in one side wall 20 of the square battery case 3 and connected between the single cells 2 and 2 with the electroconductive connection board 23 was shown, it shows in FIG. In this way, openings 21 are formed on both side walls 20 of the rectangular battery case 3 so as to face each other, and the current collectors 10 and 10 on both sides of the partition wall 5 are connected by conductive connecting plates 23 on both sides thereof. The sealing resin part 31 may be formed by pressing the injection mold 30 from both sides of the battery case 3 and performing injection molding. In this way, since the current collectors 10 and 10 are connected to each other on the both sides, the connection resistance can be further reduced, and at the time of injection molding, the rectangular battery case 3 and the internal current collector 10 and the electrode plate group 8 can be connected. Since the applied pressure is applied equally from both sides, it is possible to prevent adverse effects from being caused by the action of the load from one side on the electrode plate group 8 and the movement accompanying it.
[0032]
Next, a rectangular sealed battery according to a second embodiment of the present invention will be described with reference to FIGS. In the following description of the embodiment, the same components as those in the preceding embodiment are denoted by the same reference numerals, description thereof will be omitted, and only differences will be described.
[0033]
In the above embodiment, the conductive connection plate 23 is welded and then the opening 21 is sealed by resin molding. However, in this embodiment, the conductive connection plate 23 is attached to the current collectors 10 and 10. In addition to welding connection, the resin layer 26 is hermetically joined to the partition wall 5 and the opening edge of the opening 21 of the rectangular battery case 3, and the opening 21 formed on the side wall 20 of the rectangular battery case 3 is sealed with a closing member 32. The closing member 32 and the outer surface of the resin layer 26 are hermetically joined.
[0034]
More specifically, the opening 21 has a rectangular shape, and the conductive connecting plate 23 has a rectangular shape in which the entire shape provided with the notches 27 and the welding protrusions 28 on both sides is smaller than the opening 21. An elastic body layer 25 is provided on the outer periphery of the central portion of the conductive connecting plate 23 in the width direction, and a resin layer 26 is provided on the outer periphery thereof. The notch 22 formed in the partition wall 5 has a trapezoidal shape that spreads outward, and the edge of the portion of the opening 21 that faces the notch 22 forms an inclined extended surface 33 that continues to the slope of the trapezoidal notch 22. It is cut out like a triangle. The resin layer 26 is formed in a trapezoidal shape such that its outer shape is along the end surface of the notch 22 and the inclined extended surface 33 and its outer surface is flush with the outer surface of the side wall 20.
[0035]
The trapezoid outer surface of the resin layer 26, the end surface of the notch 22, and the inclined extended surface 33 are integrally joined in a sealed state at a heat welding line 34. Further, the closing member 32 is disposed so as to cover the opening 21 and the periphery thereof, and the closing member 32 and the outer surface of the side wall 20 and the outer surface of the resin layer 26 are integrally joined in a sealed state at the heat welding line 35. .
[0036]
Also in this embodiment, since the collectors 10 and 10 facing each other via the partition wall 5 between the single cells 2 and 2 are connected by the conductive connection plate 23, the connection resistance between the single cells 2 and 2. As a result, the internal resistance per unit cell 2 can be further reduced to achieve higher output. Moreover, since the elastic body layer 25 is provided on the outer periphery of the portion of the conductive connection plate 23 facing the partition wall 5 and the resin layer 26 of the same material as the rectangular battery case 3 is provided on the outer periphery, the rectangular battery case 3 side By thermally welding the resin layer 26 and the resin layer 26, the resin layer 26 is easily and reliably integrally joined while ensuring a sealed state, and the leakage of the electrolyte solution between the elastic body layer 25 and the resin of the rectangular battery case 3 is ensured. Can be prevented.
[0037]
Next, a rectangular sealed battery according to a third embodiment of the present invention will be described with reference to FIGS.
[0038]
In the above embodiment, the elastic body layer 25 is baked and fixed to the outer periphery of the central portion in the width direction of the conductive connecting plate 23, and the annular resin layer 26 made of a synthetic resin similar to the rectangular battery case 3 is provided on the outer periphery. Although an example is shown, in this embodiment, a baked resin layer 36 is provided on the outer periphery of the central portion in the width direction of the conductive connecting plate 23 by baking a synthetic resin having affinity with the constituent material of the rectangular battery case 3. ing. This baked resin layer 36 is charged into a heating furnace with a synthetic resin powder having a melting point lower than the injection molding temperature of the synthetic resin constituting the rectangular battery case 3 attached to the corresponding range of the conductive connecting plate 23. It is preferable to configure by baking and fixing. For example, when the rectangular battery case 3 is made of polypropylene, polyethylene, or an alloy thereof, it is preferable to bake and apply an epoxy resin powder.
[0039]
The conductive connecting plate 23 provided with such a baked resin layer 36 is disposed in the opening 21, joined to the current collector 10 on both sides of the partition wall 5 by welding 24, and then injection-molded so as to cover the opening 21. 30, the opening 21 is hermetically closed, and the sealing resin portion 31 is injection-molded so as to fill a gap between the notch 22 of the partition wall 5 and the outer periphery of the baking resin layer 36, whereby the rectangular battery case 3. And the conductive connecting plate 23 are bonded to each other through a baking resin layer 36 that is integrally adhered to the conductive connecting plate 23 and a sealing resin portion 31 that is integrally adhered thereto. 4 can be securely sealed and the opening 21 can be completely sealed.
[0040]
According to the present embodiment, since the resin on the side of the rectangular battery case 3 and the conductive connection plate 23 are joined together in an easily and surely integrated manner via the baking resin layer 36, leakage of the electrolyte The liquid can be prevented more reliably.
[0041]
In the illustrated example, the opening 21 is sealed with the sealing resin portion 31 formed by injection molding as in the first embodiment. However, as in the second embodiment, the baking resin layer 36 is illustrated. May be hermetically joined to the partition wall 5 of the rectangular battery case 3, and the opening 21 may be sealed with a closing member 32, and the closing member 32 and the outer surface of the baked resin layer 36 may be hermetically joined.
[0042]
Next, a rectangular sealed battery according to a fourth embodiment of the present invention will be described with reference to FIGS.
[0043]
In each of the above embodiments, the rectangular opening 21 facing the battery case 4 on both sides of the partition wall 5 is formed in the side wall 20 of the rectangular battery case 3, and the conductive connecting plate 23 is disposed in the opening 21 to collect the current collector. In this embodiment, as shown in FIGS. 12 and 13, each partition wall 5 on the side wall 20 of the rectangular battery case 3 is shown. Is formed at the position where the concave portion 37 having the width across the battery case 4 on both sides is formed, and a through hole 38 penetrating from the bottom surface of the concave portion 37 into the battery case 4 on both sides is formed. Conductive connectors 40 having connecting portions 39 connected to the current collectors 10 located on both sides are disposed in the recess 37, and the connecting portions 39 and the current collector 10 are joined by welding 41. As the conductive connecting member 40, a steel plate that is nickel-plated is suitable because it has resistance to an electrolytic solution and can be constructed at low cost.
[0044]
The connecting portion 39 is constituted by a round shaft-like protruding shaft, and an O-ring 42 as a sealing material is attached to the outer periphery thereof. The through hole 38 is sealed by being compressed between the conductive connecting member 40 and the conductive hole 40. The recess 37 is filled with a sealing resin 43 in a state where the conductive connection body 40 is embedded.
[0045]
Explaining the joining process in the above configuration, in the illustrated example of FIGS. 12 and 13, the concave portion 37 and the through hole 38 are formed in the side wall 20 on both sides of the rectangular battery case 3, and the O-ring 42 is attached to the connecting portion 39. The conductive connecting members 40 are respectively disposed in the recesses 37 and the connecting portions 39 are inserted into the through holes 38. Next, as shown by phantom lines in FIG. 12 and solid lines in FIG. By pressing the welding electrode 44 against the back of the connecting portions 39, 39 that are in contact with both sides of one of the current collectors 10 in the body 10, and flowing a welding current in the resistance welding machine 45 in that state. The connection portions 39 of the conductive connection body 40 are joined to both sides of the current collector 10 by welding 41, and the connection portions 39 and 39 are similarly connected to both sides of the other current collector 10 by welding 41. By joining, the current collector 10 on both sides is connected to the conductive connector 4 on both sides. Connected via a. Thereafter, an injection mold (not shown) is pressed against the side wall 20 to injection-mold the sealing resin 43, thereby completing the joining.
[0046]
In the above description, the recesses 37 are formed in the side walls 20 on both sides of the rectangular battery case 3 to dispose the conductive connection body 40, and the current collectors 10 and 10 are connected on both sides. As shown in FIG. 15, the current collectors 10 and 10 may be connected only on one side thereof. In that case, the concave portion 37 is formed only on one side wall, and through holes 38 are formed in the upper portion and the lower portion of the concave portion 37 so as to penetrate into the battery case 4 on both sides of the partition wall 5, respectively. A pair of conductive connecting members 40 that pass through the holes 38 through the connecting portions 39 on both sides and abut against the current collector 10 are arranged vertically, and an upper portion and a lower portion that are in contact with the current collector 10 on one side of the partition wall 5. The upper and lower conductive connectors 40 are connected to the current collector 10 on one side by welding 41 by pressing the welding electrode 44 against the back of the connecting portions 39, 39 and flowing a welding current with a resistance welding machine 45. Next, similarly, the welding electrode 44 is pressed against the back portions of the upper and lower connecting portions 39, 39 that are in contact with the current collector 10 on the other side of the partition wall 5, and a welding current is passed through the resistance welding machine 45. Then, the upper and lower conductive connectors 40 are connected to the current collector 10 on the other side by welding 41. Thus, the current collectors 10 on both sides of the partition wall 5 can be connected via the pair of upper and lower conductive connectors 40.
[0047]
In addition, workability | operativity will improve if the thing which has the suction channel | path 44a which adsorbs and hold | maintains the electroconductive connection body 40 is used for the welding electrode 44. FIG. In the illustrated example, the upper and lower conductive connecting members 40 are completely separate, but a single conductive connecting member integrated and integrated through a narrow portion that is difficult to pass current. Can also be used. In addition, although the connecting portion 39 is exemplified by a round shaft-like protruding shaft, a member having a rectangular cross section may be formed by bending. In that case, however, it is difficult to obtain a reliable seal.
[0048]
According to this embodiment, the through hole 38 is formed so as to penetrate into the battery case 4, 4 on both sides of the partition wall 5, and a sealing material such as an O-ring 42 is interposed between the periphery and the conductive connector 40. Therefore, high sealing performance can be easily obtained against leakage of the electrolyte.
[0049]
In the description of each of the above embodiments, a welding electrode is applied to the conductive connection plate 23 or the conductive connection body 40, and a welding current is passed between the conductive connection plate 23 or the conductive connection body 40 and the current collector 10. Although an example of resistance welding is shown, the local portion may be heated and melted by irradiation with an electron beam or a laser beam for welding. However, resistance welding is preferable because the thermal influence on the surroundings is small. In addition, a brazing material may be provided and brazed to the connecting portions of the conductive connecting plate 23, the conductive connecting body 40, and the current collector 10, or may be adhesively bonded with a conductive adhesive or the like. May be.
[0050]
【The invention's effect】
According to the rectangular sealed battery of the present invention, as is apparent from the above description, the conductivity is made through the openings formed so as to communicate with the inside of the battery case on both sides at each partitioning position of at least one side wall of the square battery case. Since the current collectors located on both sides of the partition are connected by the connecting member, the current collectors facing each other through the partition between the single cells can be connected by the conductive connection member at the side wall position of the rectangular battery case. Since the path is shortened, the connection resistance between the single cells can be reduced, and the internal resistance per single cell can be further reduced, and higher output can be realized.
[0051]
In addition, an opening is provided at each partition wall installation position on at least one side wall of the rectangular battery case so as to face the battery tanks on both sides, and the conductive connection plates disposed in the opening are connected to the current collectors located on both sides of the partition wall And when the conductive connecting plate is hermetically joined to the rectangular battery case through the elastic layer, the elastic layer is interposed between the partition wall or the side wall of the rectangular battery case and the conductive connecting plate. It is possible to prevent a separation gap from being generated between them due to a difference in thermal expansion between the conductive connecting plate and the conductive connecting plate, and to prevent leakage of the electrolyte between the single cells, thereby eliminating the possibility of a liquid junction.
[0052]
In addition, if the elastic layer is made of fluorine-based rubber, it has high electrolyte resistance and the necessary heat resistance even when the battery temperature rises. High reliability.
[0053]
In addition, if an elastic body layer is provided on the outer periphery of the part of the conductive connecting plate facing the partition wall and a resin layer of the same material as the rectangular battery case is provided on the outer periphery, it can be easily and reliably integrally joined to the resin on the square battery case side. In addition, leakage of the electrolyte solution between the elastic layer and the resin of the rectangular battery case can be further reliably prevented.
[0054]
In addition, an opening is provided at each partition wall installation position on at least one side wall of the rectangular battery case so as to face the battery tanks on both sides, and the conductive connection plates disposed in the opening are connected to the current collectors located on both sides of the partition wall In addition, when the synthetic resin having affinity with the constituent material of the rectangular battery case is baked on the conductive connection plate and sealed and bonded to the rectangular battery case, the resin on the square battery case and the conductive connection plate are obtained. Can be easily and reliably integrally joined through the baked resin layer, and leakage of the electrolyte can be reliably prevented.
[0055]
Further, if the resin layer to be baked and formed is made of a synthetic resin having a melting point lower than the injection molding temperature of the rectangular battery case, it can be more reliably integrally joined and the leakage of the electrolyte can be prevented more reliably.
[0056]
Further, the conductive connecting plate is connected to the current collector, and the periphery of the conductive connecting plate and the partition wall and the side wall of the rectangular battery case are sealed and joined by resin molding, and the opening is sealed. The configuration can be realized and the effect can be achieved.
[0057]
In addition, the conductive connecting plate is connected to the current collector, and the resin layer is hermetically bonded to the partition wall and the opening edge of the side wall of the rectangular battery case, and the opening formed on the side wall of the rectangular battery case is sealed with a closing member. At the same time, when the closing member and the outer surface of the resin layer are hermetically bonded, the above-described configuration can be realized by bonding the resins by heat welding or adhesion, and the effects thereof can be achieved.
[0058]
Also, through holes penetrating into the battery case on both sides are formed at each partition wall installation position on at least one side wall of the rectangular battery case, and connecting portions connected to the current collectors located on both sides of the partition wall through the through holes are provided on both sides. If the conductive connector is embedded in the side wall of the rectangular battery case, the through hole penetrates into the battery case on both sides. And since it seals with the sealing material between the circumference | surroundings and the electroconductive connection body, the high sealing performance with respect to the electrolyte leakage is easily obtained.
[0059]
In addition, when the connection terminals, current collectors, and current collectors at both ends of the square battery case are connected through the connection holes formed at both ends of the square battery case and the partition walls, the current collectors are connected at the top. The connection resistance can be reduced by applying the above configuration while using the manufacturing facilities of the rectangular sealed battery with the conventional configuration as it is, and the connection terminals with the outside of the rectangular sealed battery are connected to both end walls of the rectangular battery case. Since it is disposed at the top, it is easy to connect to other rectangular sealed batteries, and it is easy to ensure insulation when providing a cooling mechanism or the like by water cooling.
[Brief description of the drawings]
FIG. 1 is an overall perspective view showing a rectangular sealed battery according to a first embodiment of the present invention with a part of the rectangular battery case broken.
FIG. 2 is a transverse plan view of a main part in the same embodiment.
FIG. 3 is a perspective view of a conductive connection plate in the same embodiment.
4 is a cross-sectional view taken along arrow AA in FIG. 2;
5 is a BB arrow view of FIG. 4;
FIG. 6 is a cross-sectional plan view of a main part in a modification of the embodiment.
FIG. 7 is a cross-sectional plan view of an essential part in a second embodiment of the rectangular sealed battery of the present invention.
8 is a cross-sectional view taken along the line CC in FIG.
FIG. 9 is a view taken along the line DD in FIG.
FIG. 10 is a cross-sectional plan view of an essential part in a third embodiment of a rectangular sealed battery of the present invention.
FIG. 11 is a perspective view of a conductive connection plate in the same embodiment.
FIG. 12 is a cross-sectional plan view of an essential part in a fourth embodiment of a rectangular sealed battery of the present invention.
FIG. 13 is an enlarged cross-sectional plan view of the main part of the same embodiment.
FIG. 14 is a cross-sectional plan view of the main part in a modification of the embodiment.
15 is a vertical side view taken along the line E-E in FIG. 14 showing a bonding step between the conductive connection member and the current collector in the same modification.
FIG. 16 is a partial longitudinal sectional front view of a conventional rectangular sealed battery.
FIG. 17 is a perspective view showing a part of the battery case in the conventional example in a cutaway manner.
FIG. 18 is an explanatory diagram of an energization path in the conventional example.
[Explanation of symbols]
1 Square sealed battery
3 Square battery case
4 battery case
5 Bulkhead
8 plate group
9 (9a, 9b) Lead part
10 Current collector
12 Connection terminals
20 side walls
21 opening
23 Conductive connection board
25 Elastic layer
26 Resin layer
31 Sealing resin part
32 Closing member
34 Heat welding line
35 Heat welding line
36 Baking resin layer
38 Through hole
39 Connection
40 Conductive connector
42 O-ring (seal material)
43 Sealing resin

Claims

A rectangular battery case in which a plurality of rectangular battery cases are connected via a partition wall, a positive electrode plate and a negative electrode plate are stacked via a separator, and one side of the positive electrode plate and the negative electrode plate is protruded to the opposite sides. In the rectangular sealed battery containing the electrode plate group that is connected to the lead parts on both sides of the electrode plate group, and the electrode plate group in which the current collector is bonded to each battery case, A current collector located on both sides of the partition wall is connected to each partition wall installation position on at least one side wall of the rectangular battery case through a conductive connection member through an opening formed so as to communicate with the inside of the battery case on both sides. A square sealed battery.

An opening is provided at each partition wall installation position on at least one side wall of the rectangular battery case so as to face the battery tanks on both sides, and the conductive connection plates disposed in the opening are connected to current collectors located on both sides of the partition wall, 2. The rectangular sealed battery according to claim 1, wherein the conductive connecting plate is hermetically bonded to the rectangular battery case through an elastic layer.

3. The square sealed battery according to claim 2, wherein the elastic layer is made of fluorine rubber.

4. The rectangular sealed battery according to claim 2, wherein an elastic body layer is provided on an outer periphery of a portion of the conductive connecting plate facing the partition wall, and a resin layer of a similar material to the rectangular battery case is provided on the outer periphery thereof. .

An opening is provided at each partition wall installation position on at least one side wall of the rectangular battery case so as to face the battery tanks on both sides, and the conductive connection plates disposed in the opening are connected to current collectors located on both sides of the partition wall, 2. The rectangular sealed battery according to claim 1, wherein the rectangular sealed battery is hermetically bonded to the rectangular battery case through a resin layer formed by baking a synthetic resin having an affinity for the constituent material of the rectangular battery case on the conductive connecting plate. .

6. The square sealed battery according to claim 5, wherein the resin layer is made of a synthetic resin having a melting point lower than the injection molding temperature of the rectangular battery case.

3. The conductive connecting plate is connected to a current collector, and the periphery of the conductive connecting plate and the partition wall and the side wall of the rectangular battery case are hermetically bonded by resin molding and the opening is sealed. The square sealed battery according to 4, 5, or 6.

The conductive connecting plate is connected to the current collector, the resin layer is hermetically bonded to the partition wall and the opening edge of the side wall of the rectangular battery case, and the opening formed on the side wall of the square battery case is sealed with a closing member. 7. The square sealed battery according to claim 4, 5 or 6, wherein the closing member and the outer surface of the resin layer are hermetically joined.

A through-hole that penetrates into the battery case on both sides is formed at each partitioning position of at least one side wall of the rectangular battery case, and a connecting portion that is connected to the current collector located on both sides of the partition wall through the through-hole is provided on both sides. 2. The square sealed type according to claim 1, wherein a conductive connection body is provided, a sealing material is provided between the periphery of the through hole and the conductive connection body, and the conductive connection body is embedded in a side wall of the rectangular battery case. battery.

The current collector and the current collectors are connected to each other through the connection terminals formed at both ends of the square battery case and through the connection holes formed at both ends of the square battery case and the upper part of the partition wall. A square sealed battery according to claim 1.