JP3670884B2

JP3670884B2 - Collective storage battery

Info

Publication number: JP3670884B2
Application number: JP12250199A
Authority: JP
Inventors: 通則池添; 貴史小田; 英樹岡島
Original assignee: Sanyo Electric Co Ltd
Current assignee: Sanyo Electric Co Ltd
Priority date: 1999-04-28
Filing date: 1999-04-28
Publication date: 2005-07-13
Anticipated expiration: 2019-04-28
Also published as: JP2000315492A

Description

【０００１】
【発明の属する技術分野】
この発明は、ニッケル・水素蓄電池、ニッケル・カドミウム蓄電池、リチウムイオン蓄電池、鉛蓄電池などの蓄電池に係り、特に、単電池の複数個を導電接続して形成された集合型蓄電池に関する。
【０００２】
【従来の技術】
近年、蓄電池の用途の拡大とともに大容量の蓄電池が求められるようになり、特に、大容量の単電池を多数個接続して組電池とし、この組電池を多数組接続した集合型蓄電池が電気自動車用に開発されるようになった。このように大容量にした集合型蓄電池においては、単電池の上部に設けられた正極柱を連結部材を介してこの単電池の一方に隣接する単電池の上部に設けられた負極柱に接続し、単電池の上部に設けられた負極柱を連結部材を介してこの単電池の他方に隣接する単電池の上部に設けられた正極柱に接続して組電池とするようになされている。
【０００３】
ところで、上述した連結部材が腐食されると電気抵抗が増大して、抵抗電圧降下が大きくなって組電池としての性能が大幅に低下するため、連結部材を各端子間に接続した後、これらの上部にキャップを被せるようにしている。しかしながら、連結部材と各端子の上部にキャップを被せても、キャップの下部を密閉することが困難であるため、連結部材を外気から遮断することができなく、急激な温度変動による結露、雨中の走行あるいは洗車などによる水の侵入等によって連結部材の腐食を防止することが難しかった。
【０００４】
【発明が解決しようとする課題】
そこで、連結部材の腐食を防止できるようにした接続構造が特開平１０−６４５０７号公報にて提案された。この特開平１０−６４５０７号公報にて提案された接続構造は、図３に示すように、銅からなる導電板５１の周囲にはクロロプレンゴムからなる保護層５２が一体成形されており、さらに極柱４２，４３と導電板５１を電気的に接続する際、導電板５１の単電池側に作られたクロロプレンゴムからなる環状の突起５３が単電池の電槽蓋体４１の表面に押圧固定されている。また導電板５１と極柱４２，４３を電気的に接続した後、導電板５１の単電池側の反対側に設けられたクロロプレンゴムからなる環状の突起物５４にクロロプレンゴムからなる連結板蓋体５５がはめあい固定されている。
【０００５】
しかしながら、特開平１０−６４５０７号公報において提案された接続構造にあっては、導電板５１の周囲にはクロロプレンゴムからなる保護層５２が一体成形されており、かつ環状の突起物５４に連結板蓋体５５がはめあい固定されているため、液密・気密性は向上するが、連結板蓋体５５等の部品を必要とするため、部品点数が多くなってこの種の電池が高価になるという問題を生じた。また、連結板蓋体５５を環状の突起物５４にはめあいにより固定するだけであるため、連結板蓋体５５は外れやすく、取付の信頼性が低いという問題も生じた。
【０００６】
また、連結板蓋体５５をはめあいにより環状の突起物５４に固定することに代えて、熱溶着あるいは接着等により固定することも考えられるが、熱溶着あるいは接着等の工程が増大するとともに、連結板蓋体５５を取り外すことができなくなり、この種の集合型蓄電池の保守性が低下するという問題も生じた。
そこで、本発明は上記問題点を解決するためになされたものであって、部品点数が増加することなく、簡単な構造で信頼性の高いシール構造が得られるようにすることを目的とするものである。
【０００７】
【課題を解決するための手段およびその作用・効果】
上記目的を達成するため、本発明の集合型蓄電池は、単電池に相隣接する他の単電池に導電接続される正極用極柱および負極用極柱を各単電池に備えるとともに、各単電池に備えられた両極柱を相隣接する各単電池に備えられた両極柱の極性に応じて選択的に導電接続する連結部材と、この連結部材を各極柱に螺着により固定する固定具とを備え、両極柱の端部は固定具を螺着するための螺着部を備え、連結部材は金属板とこの金属板の表面に被覆された被覆層とから構成され、固定具は金属製ナットとこの金属製ナットの表面に形成された保護層とから構成されるようにしている。
【０００８】
このように、連結部材に被覆層を備えるとともに、連結部材を端子に螺着により固着する固定具は金属製ナットとこの金属製ナットの表面に形成された保護層とから構成されるようにすると、固定具を端子に螺着することにより、固定具の保護層は連結部材の被覆層に密着するため、各端子は液密・気密に封止される。この結果、簡単な構造で、信頼性の高いシール構造が得られ、連結部材の耐久性を向上させることが可能となる。また、保護層と被覆層との間にシール層を備えるようにすると、さらに信頼性の高いシール構造が得られて、連結部材の耐久性がさらに向上する。
【０００９】
そして、被覆層の構成材はクロロプレンゴム、合成天然ゴム、スチレンゴム、ブタジエンゴム、ブチルゴム、ニトリルゴム、エチレンプロピレンゴム、アクリルゴム、シリコンゴム、ポリプロピレン樹脂、ポリエチレン樹脂、ポリフェニレンエーテル樹脂とポリスチレン樹脂との共重合体、ＡＢＳ樹脂のいずれかから選択し、保護層の構成材はポリプロピレン樹脂、ポリエチレン樹脂、ポリフェニレンエーテル樹脂とポリスチレン樹脂との共重合体、ＡＢＳ樹脂のいずれかから選択するようにすると、これらの各材質の弾力性により、保護層は被覆層に強固に密着するようになるため、各端子はさらに液密・気密に封止される。
【００１０】
さらに、保護層の被覆層との接触面に環状パッキングを備えたり、保護層の被覆層との接触面に環状突部を備えたり、被覆層の単電池との接触面に環状突部を備えたり、あるいは保護層の被覆層との接触面に環状突部を備えるとともに被覆層の単電池との接触面に環状突部を備えると、被覆層と単電池との間、保護層と被覆層との間がより以上に液密・気密に封止されるようになる。また、保護層は固定具とモールド成型により一体的に形成されていると、簡単な構成で部品点数も少なく、かつ少ない工程で容易にシール性を確保できるようになる。
【００１１】
【発明の実施の形態】
以下、本発明の集合型蓄電池をアルカリ蓄電池に適用した場合の一実施の形態を図１、図２に基づいて説明する。なお、図１は集合型アルカリ蓄電池とするための本実施形態の単電池の外観を示す斜示図であり、図２は図１の単電池を２個導電接続した場合の要部の断面を示す断面図である。
【００１２】
１．正極板の作製
所定量の水酸化ニッケル活物質に所定量のヒドロキシプロピルセルロース水溶液を混合して作製した活物質スラリーを所定の厚みのニッケル多孔体（例えば、ニッケルスポンジ）に含浸した後、その表面にフッ素樹脂（ポリテトラフルオロエチレン，ＰＴＦＥ）ディスパージョンを噴霧し、乾燥させた後、所定の厚みになるまで圧延し、所定形状（例えば、幅１００ｍｍ、高さ１２０ｍｍ）に切断してニッケル正極板１１を作製した。
【００１３】
２．負極板の作製
ミッシュメタル（Ｍｍ：希土類元素の混合物）、ニッケル、コバルト、アルミニウム、およびマンガンを所定の比率で混合し、この混合物をアルゴンガス雰囲気の高周波誘導炉で誘導加熱して合金溶湯とした後、冷却して水素吸蔵合金のインゴットを作製する。この水素吸蔵合金インゴットを機械的に粗粉砕した後、不活性ガス雰囲気中で平均粒子径が約１５０μｍになるまで機械的に粉砕する。この水素吸蔵合金粉末にポリエチレンオキサイド等の結着剤と、適量の水を加えて混合して水素吸蔵合金スラリーを作製する。このスラリーをパンチングメタルからなる活物質保持体の両面に、圧延後の活物質密度が所定量になるように塗着した後、乾燥、圧延を行った後、所定寸法（例えば、幅１００ｍｍ、高さ１２０ｍｍ）に切断して水素吸蔵合金負極板１２を作製した。
【００１４】
３．ニッケル−水素蓄電池の作製
ついで、上述のように作製したニッケル正極板１１と水素吸蔵合金負極板１２とをポリプロピレン製不織布からなるセパレータ（図示せず）を介して積層して、極板群１０ａを作製した。なお、この極板群１０ａは、例えば正極板１１を１７枚、負極板１２を１８枚用いて作製された。この極板群１０ａを合成樹脂（例えばポリプロピレン）製の電槽１５内に挿入した後、蓋体１６に設けられた正極柱１３の下端と各正極板１１から延出する集電体１１ａとを溶接により接続固定するとともに、同様に蓋体１６に設けられた負極柱１４の下端と各負極板１２から延出する集電体１２ａとを溶接により接続固定した。
【００１５】
ついで、電解液（例えば、水酸化カリウム（ＫＯＨ）、水酸化ナトリウム（ＮａＯＨ）、水酸化リチウム（ＬｉＯＨ）などのアルカリ金属の水酸化物を混合した水溶液を用いる）を電槽１５内に注入した後、電槽１５の上部開口部に合成樹脂製の蓋体１６を熱溶着して、公称容量が１００Ａｈのニッケル−水素蓄電池１０を作製した。なお、正極柱１３および負極柱１４の蓋体１６より外部に突出する部分にはそれぞれねじ部１３ａ，１４ａが配設されている。なお、正極柱１３および負極柱１４はプッシュナット１７により蓋体１６に固定されている。なお、蓋体１６の中央部には安全弁１８が設けられている。
【００１６】
４．連結部材の作製
導電性が良好な銅にニッケルメッキを施した金属板からなる導電板２１に正極柱用貫通孔２２および負極柱用貫通孔２３を配設するとともに、これらの貫通孔２２，２３の周囲部２２ａ，２３ａを除く全表面にクロロプレンゴムからなる被覆層２４を一体的にモールド成型して連結部材２０を作製した。この連結部材２０の被覆層２４の下面には、各貫通孔２２，２３の周囲を取り囲むようにして環状突部２５，２６が配設されている。なお、導電板２１としては鉄にニッケルメッキを施した金属板あるいはニッケル板を用いてもよい。
【００１７】
なお、被覆層２４を形成する材料としては、クロロプレンゴム以外に合成天然ゴム、スチレンゴム、ブタジエンゴム、ブチルゴム、ニトリルゴム、エチレンプロピレンゴム、アクリルゴム、シリコンゴム、ポリプロピレン樹脂、ポリエチレン樹脂、ポリフェニレンエーテル樹脂とポリスチレン樹脂との共重合体、ＡＢＳ樹脂のいずれかから選択するのが好ましい。また、被覆層２４を形成するに際して、硬度が異なる材質の複数層を備えるようにしてもよい。この場合、外層ほど硬度が小さい（柔らかい）材質とするのが好ましい。また、環状突部２５，２６に代えてこれらと同材質よりなる環状パッキングを用いるようにしても良い。
【００１８】
５．固定具の作製
一方、ニッケルメッキを施した金属からなるナット部３１の表面にポリアミド樹脂からなる保護層３２を一体的にモールド成型して固定具３０を作製した。この固定具３０の保護層３２はナット部３１の周囲全体を覆う断面形状が略コの字状の本体部３２ａと、本体部３２ａの底辺部となるフランジ部３２ｂとから構成され、フランジ部３２ｂの下面にはナット部３１の周囲を取り囲むようにして環状突部３３が配設されている。
【００１９】
なお、保護層３２を形成する材料としては、ポリアミド樹脂以外にポリプロピレン樹脂、ポリエチレン樹脂、ポリフェニレンエーテル樹脂とポリスチレン樹脂との共重合体、ＡＢＳ樹脂のいずれかから選択するのが好ましい。また、保護層３２を形成するに際して、硬度が異なる材質の複数層を備えるようにしてもよい。この場合、外層ほど硬度が小さい（柔らかい）材質とするのが好ましい。また、環状突部３３に代えてこれらと同材質よりなる環状パッキングを用いるようにしても良い。
【００２０】
６．組電池および集合型電池の作製
上述のようにして作製したニッケル−水素蓄電池１０を１０個用意し、これらの各ニッケル−水素蓄電池１０の各正極柱１３および負極柱１４の極性が互いに逆極性となるように厚み方向に横一列になるように配置する。ついで、図２に示すように、電池Ａの正極柱１３に連結部材２０の正極柱用貫通孔２２を挿通させ、電池Ｂの負極柱１４に連結部材２０の負極柱用貫通孔２３を挿通させた後、電池Ａの正極柱１３および電池Ｂの負極柱１４にワッシャー２７をそれぞれ挿入する。
【００２１】
同様に、電池Ｂの正極柱１３（図示せず）に連結部材２０の正極柱用貫通孔２２を挿通させ、電池Ｃ（図示せず）の負極柱１４（図示せず）に連結部材２０の負極柱用貫通孔２３を挿通させた後、電池Ｂの正極柱１３および電池Ｃの負極柱１４にワッシャー２７をそれぞれ挿入する。この後、これらの各極柱１３，１４にそれぞれ固定具３０を螺着させる。同様の操作を繰り返して、１０個のニッケル−水素蓄電池１０が直列に接続された実施例の組電池を作製した。なお、固定具３０にワッシャー２７が一体化されていればワッシャー２７を挿入する工程は省略できる。
【００２２】
一方、図３に示すように、上述した従来例の連結部材５０を用い、この連結部材５０により各単電池４０を１０個直列に接続した後、これらの各連結部材５０の環状の突起物５４に連結板蓋体５５をはめあい固定して、１０個のニッケル−水素蓄電池４０が直列に接続された比較例の組電池を作製した。この場合、各極柱４２，４３に連結部材５０を挿通させた後、ワッシャー５６を介してナット５７，５７で螺着して各極柱４２，４３を固着し、これらの各連結部材５０の環状の突起物５４に連結板蓋体５５をはめあい固定することにより比較例の組電池が作製される。
【００２３】
７．試験
上述のようにして作製した実施例の組電池１０個と、比較例の組電池１０個とを用意し、これらの各組電池をＪＩＳ−Ｚ−２３７１に基づく塩水噴霧試験を５００時間行い、その前後による出力密度の変化と漏液状況を測定すると、下記の表１に示すような結果となった。なお、出力密度はＳＢＡ１２５０３に基づく試験によって測定し、漏液状況は各極柱１３，１４および各極柱４２，４３の周辺のアルカリ反応の有無によって測定した。
【００２４】
【表１】

【００２５】
上記表１より明らかなように、実施例のニッケル−水素蓄電池１０は塩水の噴霧前後において平均出力密度(Ｗ/ｋｇ)が変化していないのに対して、比較例のニッケル−水素蓄電池４０は塩水の噴霧前後において平均出力密度(Ｗ/ｋｇ)が変化していることが分かる。これは、比較例のニッケル−水素蓄電池４０においては、単に連結板蓋体５５をはめあい固定しているだけであるため、単電池４０の上面の連結部材５０が腐食して抵抗が増大し、抵抗電圧降下が大きくなって平均出力密度が低下したと考えられる。また、比較例のニッケル−水素蓄電池４０にあっては、単に連結板蓋体５５をはめあい固定しているだけであるため、連結板蓋体５５に外力が加わった場合に連結板蓋体５５が外れる恐れがある。
【００２６】
一方、実施例のニッケル−水素蓄電池１０にあっては、保護層３２がモールド成型により一体的に形成された固定具３０の締め付け力を利用して、各極柱１３，１４を螺着させるようにしているため、固定具３０に外力が加わっても外れることはない。また、固定具３０のフランジ部３２ｂの下面にはナット部３１の周囲を取り囲むようにして環状突部３３が配設されているとともに、連結部材２０の被覆層２４の下面には、各貫通孔２２，２３の周囲を取り囲むようにして環状突部２５，２６が配設されているので、塩水を噴霧しても連結部材２０の導電板２１および各極柱１３，１４が腐食されることはない。このため、この部分での電圧降下が生じなく、平均出力密度(Ｗ/ｋｇ)も低下しない。
【００２７】
８．部品点数の検討
ついで、上述した実施例と比較例の各電池の接続部での部品点数を、１接続部分での部品点数、１０セルの組電池とした場合の部品点数、および１０セルの組電池を２４組接続（２４０セル（ＥＶ１台分））とした場合の部品点数をそれぞれ算出すると、下記の表２に示すような結果となった。
【００２８】
【表２】

【００２９】
上記表２より明らかなように、実施例の場合の１接続部分での部品点数にあっては、１つの連結部材２０と２つの固定具３０との３部品を必要とし、比較例の場合の１接続部分での部品点数にあっては、１つの連結部材５０と２つのナット５７，５７と２つの連結板蓋体５５，５５との５部品を必要とする。このため、１０セルを用いて組電池とすると、実施例の場合は２７部品を必要とし、比較例の場合は４５部品を必要とし、この１０セルの組電池を１２組用いて２４０セルの集合型電池(ＥＶ１台分)と、実施例の場合は６４８部品を必要とし、比較例の場合は１０８０部品を必要とする。このように、本実施例のように、部品点数を削減することが可能になると、製造工数が大幅に低減させることができるようになるため、この種の集合型蓄電池の製造が容易になるとともに、安価に製造できるようになる。
【００３０】
上述したように、本発明においては、導電性を有する連結部材２０は金属板２１の表面に被覆層２４を備えるとともに、固定具３０の表面に各極柱１３，１４を液密・気密に封止する保護層３２を備えるようにしているので、固定具３０を各極柱１３，１４に螺着することにより、固定具３０の保護層３２は連結部材２０の被覆層２４に密着するため、各極柱１３，１４は液密・気密に封止される。この結果、簡単な構造で、信頼性の高いシール構造が得られ、連結部材２０の耐久性を向上させることが可能となる。
【００３１】
また、被覆層２４の単電池１０の蓋体１６との接触面に環状突部２５，２６を備え、保護層３２の被覆層２４との接触面に環状突部３３を備えているので、被覆層２４と単電池１０の蓋体１６との間、保護層３２と被覆層２４との間がより以上に液密・気密に封止されるようになる。さらに、保護層３２は固定具３０とモールド成型により一体的に形成されているので、簡単な構成で部品点数も少なく、かつ少ない工程で容易にシール性を確保できるようになる。なお、各環状突部２５，２６および３３を設けることに代えてこれらと同等の材質よりなる環状パッキングを用いても同様な効果が得られる。
【００３２】
なお、上述した実施形態においては、連結部材２０の被覆層２４の構成材としてクロロプレンゴムを用いる例について説明したが、クロロプレンゴム以外に、合成天然ゴム、スチレンゴム、ブタジエンゴム、ブチルゴム、ニトリルゴム、エチレンプロピレンゴム、アクリルゴム、シリコンゴム、ポリプロピレン樹脂、ポリエチレン樹脂、ポリフェニレンエーテル樹脂とポリスチレン樹脂との共重合体、ＡＢＳ樹脂のいずれかから選択して用いてもほぼ同様の結果が得られた。
【００３３】
また、上述した実施形態においては、固定具３０の保護層３２の構成材としてポリアミド樹脂を用いる例について説明したが、ポリアミド樹脂以外にポリプロピレン樹脂、ポリエチレン樹脂、ポリフェニレンエーテル樹脂とポリスチレン樹脂との共重合体、ＡＢＳ樹脂のいずれかから選択して用いてもほぼ同様の結果が得られた。
【００３４】
なお、上述した実施形態においては、本発明を角形蓄電池に適用する例についてのみ説明したが、本発明は角形蓄電池に限らず、円筒型、楕円型等の他の形状の蓄電池にも適用できることは無論である。また、本発明をニッケル−水素蓄電池に適用する例についてのみ説明したが、本発明はニッケル−水素蓄電池以外に、リチウムイオン蓄電池、ニッケル・カドミウム蓄電池、鉛蓄電池などの各種の電池に適用できることは無論である。
【図面の簡単な説明】
【図１】集合型アルカリ蓄電池とするための本実施形態の単電池の外観を示す斜示図である。
【図２】図１の単電池を２個導電接続した場合の要部の断面を示す断面図である。
【図３】従来例（比較例）の集合型アルカリ蓄電池の要部を示す断面図である。
【符号の説明】
１０…ニッケル−水素蓄電池（単電池）、１０ａ…極板群、１１…正極板、１２…負極板、１３…正極柱、１３ａ…ねじ部、１４…負極柱、１４ａ…ねじ部、１５…電槽、１６…蓋体、２０…連結部材、２１…導電板、２２…正極柱用貫通孔、２３…負極柱用貫通孔、２４…被覆層、２５，２６…環状突部、３０…固定具、３１…ナット部、３２…保護層、３２ａ…本体部、３２ｂ…フランジ部、３３…環状突部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a storage battery such as a nickel / hydrogen storage battery, a nickel / cadmium storage battery, a lithium ion storage battery, or a lead storage battery, and more particularly to a collective storage battery formed by electrically connecting a plurality of unit cells.
[0002]
[Prior art]
In recent years, with the expansion of the use of storage batteries, a large capacity storage battery has been demanded. In particular, a large capacity storage battery is connected to form an assembled battery, and a collective storage battery in which many such assembled batteries are connected is an electric vehicle. Has been developed for. In the collective storage battery having such a large capacity, the positive pole provided on the upper part of the unit cell is connected to the negative pole provided on the upper part of the unit cell adjacent to one of the unit cells via a connecting member. The negative electrode column provided on the upper part of the unit cell is connected to the positive electrode column provided on the upper part of the unit cell adjacent to the other side of the unit cell via a connecting member to form an assembled battery.
[0003]
By the way, if the connecting member described above is corroded, the electrical resistance increases, the resistance voltage drop increases, and the performance as an assembled battery is greatly reduced. The top is covered with a cap. However, since it is difficult to seal the lower part of the cap even when the cap is put on the upper part of the connecting member and each terminal, the connecting member cannot be shut off from the outside air. It has been difficult to prevent corrosion of the connecting member due to water intrusion or the like due to traveling or car washing.
[0004]
[Problems to be solved by the invention]
Therefore, a connection structure that can prevent the corrosion of the connecting member has been proposed in Japanese Patent Laid-Open No. 10-64507. In the connection structure proposed in Japanese Patent Laid-Open No. 10-64507, as shown in FIG. 3, a protective layer 52 made of chloroprene rubber is integrally formed around a conductive plate 51 made of copper. When the columns 42 and 43 and the conductive plate 51 are electrically connected, an annular protrusion 53 made of chloroprene rubber made on the single cell side of the conductive plate 51 is pressed and fixed to the surface of the battery case lid 41 of the single cell. ing. In addition, after electrically connecting the conductive plate 51 and the poles 42 and 43, a connecting plate lid made of chloroprene rubber is formed on an annular protrusion 54 made of chloroprene rubber provided on the opposite side of the conductive plate 51 from the single battery side. 55 is fixed by fitting.
[0005]
However, in the connection structure proposed in Japanese Patent Laid-Open No. 10-64507, a protective layer 52 made of chloroprene rubber is integrally formed around the conductive plate 51, and the connecting plate is connected to the annular protrusion 54. Since the lid 55 is fitted and fixed, the liquid-tightness and air-tightness are improved. However, since components such as the connecting plate lid 55 are required, the number of parts is increased and this type of battery is expensive. Caused a problem. Further, since the connecting plate cover 55 is only fixed to the annular protrusion 54 by fitting, the connecting plate cover 55 is easily detached, and there is a problem that the mounting reliability is low.
[0006]
Further, instead of fixing the connecting plate lid 55 to the annular protrusion 54 by fitting, it may be fixed by heat welding or adhesion, but the number of steps such as heat welding or adhesion increases, and the connection The plate lid 55 could not be removed, and there was a problem that the maintainability of this type of collective storage battery was lowered.
Accordingly, the present invention has been made to solve the above-described problems, and an object thereof is to obtain a highly reliable seal structure with a simple structure without increasing the number of parts. It is.
[0007]
[Means for solving the problems and their functions and effects]
In order to achieve the above object, the battery assembly of the present invention includes a positive pole for a positive electrode and a negative pole for a negative electrode, which are conductively connected to another single battery adjacent to the single battery, and each single battery. A connecting member that selectively conducts conductive connection between the two pole columns provided in each of the adjacent unit cells according to the polarities of the two pole columns; and a fixture that fixes the connecting member to each pole column by screwing. The end of each pole pole has a screwed portion for screwing the fixture, the connecting member is composed of a metal plate and a coating layer coated on the surface of the metal plate, and the fixture is made of metal It is comprised from a nut and the protective layer formed in the surface of this metal nut.
[0008]
As described above, the connecting member is provided with the coating layer, and the fixture for fixing the connecting member to the terminal by screwing is configured by the metal nut and the protective layer formed on the surface of the metal nut. By screwing the fixture to the terminal, the protective layer of the fixture comes into close contact with the coating layer of the connecting member, so that each terminal is sealed in a liquid-tight and air-tight manner. As a result, a highly reliable seal structure can be obtained with a simple structure, and the durability of the connecting member can be improved. Further, when a sealing layer is provided between the protective layer and the covering layer, a more reliable sealing structure is obtained, and the durability of the connecting member is further improved.
[0009]
The constituent material of the covering layer is chloroprene rubber, synthetic natural rubber, styrene rubber, butadiene rubber, butyl rubber, nitrile rubber, ethylene propylene rubber, acrylic rubber, silicon rubber, polypropylene resin, polyethylene resin, polyphenylene ether resin and polystyrene resin. These are selected from either a copolymer or ABS resin, and the constituent material of the protective layer is selected from any of polypropylene resin, polyethylene resin, copolymer of polyphenylene ether resin and polystyrene resin, and ABS resin. Due to the elasticity of each material, the protective layer comes into close contact with the coating layer, so that each terminal is further sealed liquid-tight and air-tight.
[0010]
Furthermore, an annular packing is provided on the contact surface of the protective layer with the coating layer, an annular protrusion is provided on the contact surface of the protective layer with the coating layer, or an annular projection is provided on the contact surface of the coating layer with the unit cell. Or when the contact surface of the protective layer with the covering layer is provided with an annular protrusion and the contact surface of the covering layer with the unit cell is provided with an annular protrusion, the protective layer and the covering layer are provided between the covering layer and the unit cell. Is more liquid-tight and air-tight. Further, when the protective layer is integrally formed with the fixture and molding, the number of parts is reduced with a simple configuration, and the sealing performance can be easily ensured with fewer steps.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, one embodiment when the collective storage battery of the present invention is applied to an alkaline storage battery will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective view showing the external appearance of the unit cell of this embodiment for making a collective alkaline storage battery, and FIG. 2 is a cross-sectional view of the main part when two unit cells of FIG. 1 are conductively connected. It is sectional drawing shown.
[0012]
1. Preparation of positive electrode plate A surface of a porous nickel material (for example, nickel sponge) impregnated with an active material slurry prepared by mixing a predetermined amount of an aqueous solution of hydroxypropylcellulose with a predetermined amount of nickel hydroxide active material, and then its surface A fluorine resin (polytetrafluoroethylene, PTFE) dispersion is sprayed on the substrate, dried, rolled to a predetermined thickness, cut into a predetermined shape (for example, width 100 mm, height 120 mm), and a nickel positive electrode plate 11 was produced.
[0013]
2. Production of Negative Electrode Misch Metal (Mm: Mixture of Rare Earth Elements), Nickel, Cobalt, Aluminum, and Manganese were mixed at a predetermined ratio, and this mixture was induction-heated in a high-frequency induction furnace in an argon gas atmosphere to obtain a molten alloy. Then, it cools and the ingot of a hydrogen storage alloy is produced. The hydrogen storage alloy ingot is mechanically coarsely pulverized and then mechanically pulverized in an inert gas atmosphere until the average particle size becomes about 150 μm. A hydrogen storage alloy slurry is prepared by adding a binder such as polyethylene oxide and an appropriate amount of water to the hydrogen storage alloy powder and mixing them. After applying this slurry on both surfaces of an active material holder made of punching metal so that the active material density after rolling becomes a predetermined amount, drying and rolling, the slurry is then subjected to predetermined dimensions (for example, width 100 mm, high To 120 mm), a hydrogen storage alloy negative electrode plate 12 was produced.
[0014]
3. Next, the nickel positive electrode plate 11 and the hydrogen storage alloy negative electrode plate 12 manufactured as described above are laminated via a separator (not shown) made of polypropylene nonwoven fabric, and the electrode plate group 10a is formed. Produced. In addition, this electrode group 10a was produced using, for example, 17 positive plates 11 and 18 negative plates 12. After this electrode plate group 10a is inserted into a battery case 15 made of synthetic resin (for example, polypropylene), a lower end of the positive pole 13 provided on the lid 16 and a current collector 11a extending from each positive electrode plate 11 are provided. In addition to being connected and fixed by welding, similarly, the lower end of the negative pole 14 provided on the lid 16 and the current collector 12 a extending from each negative electrode plate 12 were connected and fixed by welding.
[0015]
Next, an electrolytic solution (for example, an aqueous solution in which an alkali metal hydroxide such as potassium hydroxide (KOH), sodium hydroxide (NaOH), or lithium hydroxide (LiOH) is mixed) is injected into the battery case 15. Thereafter, a lid 16 made of synthetic resin was thermally welded to the upper opening of the battery case 15 to produce a nickel-hydrogen storage battery 10 having a nominal capacity of 100 Ah. Note that screw portions 13 a and 14 a are respectively disposed on portions of the positive pole 13 and the negative pole 14 that protrude outward from the lid 16. The positive pole 13 and the negative pole 14 are fixed to the lid 16 by a push nut 17. A safety valve 18 is provided at the center of the lid body 16.
[0016]
4). Fabrication of connecting member A positive electrode column through hole 22 and a negative electrode column through hole 23 are provided on a conductive plate 21 made of a metal plate obtained by plating nickel with copper having good conductivity, and these through holes 22, 23. A connecting member 20 was manufactured by integrally molding a coating layer 24 made of chloroprene rubber on the entire surface except the peripheral portions 22a and 23a of the chloroprene. On the lower surface of the covering layer 24 of the connecting member 20,

annular protrusions

25 and 26 are disposed so as to surround the peripheries of the through holes 22 and 23. The conductive plate 21 may be a metal plate obtained by applying nickel plating to iron or a nickel plate.
[0017]
In addition to chloroprene rubber, synthetic natural rubber, styrene rubber, butadiene rubber, butyl rubber, nitrile rubber, ethylene propylene rubber, acrylic rubber, silicon rubber, polypropylene resin, polyethylene resin, polyphenylene ether resin can be used as the material for forming the coating layer 24. It is preferable to select any one of a copolymer of polystyrene resin and ABS resin. Moreover, when forming the coating layer 24, you may make it provide the several layer of the material from which hardness differs. In this case, the outer layer is preferably made of a material having a lower hardness (softer). Further, instead of the

annular protrusions

25 and 26, an annular packing made of the same material as these may be used.
[0018]
5. On the other hand, a fixture 30 was produced by integrally molding a protective layer 32 made of polyamide resin on the surface of a nut portion 31 made of nickel-plated metal. The protective layer 32 of the fixture 30 includes a body portion 32a having a substantially U-shaped cross section covering the entire periphery of the nut portion 31, and a flange portion 32b serving as a bottom side portion of the body portion 32a. An annular protrusion 33 is disposed on the lower surface of the nut so as to surround the periphery of the nut portion 31.
[0019]
In addition to the polyamide resin, the material for forming the protective layer 32 is preferably selected from any of polypropylene resin, polyethylene resin, a copolymer of polyphenylene ether resin and polystyrene resin, and ABS resin. Moreover, when forming the protective layer 32, you may make it provide the several layer of the material from which hardness differs. In this case, the outer layer is preferably made of a material having a lower hardness (softer). Further, instead of the annular protrusion 33, an annular packing made of the same material as these may be used.
[0020]
6). Preparation of assembled battery and assembled battery 10 nickel-hydrogen storage batteries 10 prepared as described above were prepared, and the polarity of each positive pole 13 and negative pole 14 of each nickel-hydrogen storage battery 10 was opposite to each other. It arrange | positions so that it may become horizontal row in a thickness direction. Next, as shown in FIG. 2, the positive pole post 13 of the connecting member 20 is inserted into the positive pole 13 of the battery A, and the negative pole post through hole 23 of the connecting member 20 is inserted into the negative pole 14 of the battery B. After that, the washer 27 is inserted into the positive pole 13 of the battery A and the negative pole 14 of the battery B, respectively.
[0021]
Similarly, the positive pole post 13 (not shown) of the battery B is inserted into the through hole 22 for the positive pole of the connecting member 20, and the connecting pole 20 (not shown) of the battery C (not shown) is inserted into the negative pole 14 (not shown). After inserting the through hole 23 for the negative pole, the washer 27 is inserted into the positive pole 13 of the battery B and the negative pole 14 of the battery C, respectively. Thereafter, the fixing tool 30 is screwed to each of the pole columns 13 and 14. The same operation was repeated to produce an assembled battery of an example in which ten nickel-hydrogen storage batteries 10 were connected in series. If the washer 27 is integrated with the fixture 30, the step of inserting the washer 27 can be omitted.
[0022]
On the other hand, as shown in FIG. 3, after using the connecting member 50 of the conventional example described above and connecting each of the unit cells 40 in series by the connecting member 50, the annular protrusion 54 of each connecting member 50. The connection plate lid 55 was fitted and fixed to the battery, and a battery assembly of a comparative example in which 10 nickel-hydrogen storage batteries 40 were connected in series was produced. In this case, after the connecting members 50 are inserted into the respective pole columns 42 and 43, the respective pole columns 42 and 43 are fixed by screwing with the nuts 57 and 57 via the washers 56. An assembled battery of a comparative example is manufactured by fitting and fixing the connecting plate lid 55 to the annular protrusion 54.
[0023]
7. Test 10 assembled batteries of Examples prepared as described above and 10 assembled batteries of Comparative Examples were prepared, and each of these assembled batteries was subjected to a salt spray test based on JIS-Z-2371 for 500 hours, When the change in the output density before and after that and the leakage situation were measured, the results shown in Table 1 below were obtained. The power density was measured by a test based on SBA12503, and the leakage state was measured by the presence or absence of an alkaline reaction around each pole column 13, 14 and each pole column 42, 43.
[0024]
[Table 1]

[0025]
As is clear from Table 1 above, the nickel-hydrogen storage battery 10 of the example does not change the average power density (W / kg) before and after spraying salt water, whereas the nickel-hydrogen storage battery 40 of the comparative example It can be seen that the average power density (W / kg) changes before and after spraying salt water. This is because, in the nickel-hydrogen storage battery 40 of the comparative example, the connecting plate lid 55 is simply fitted and fixed, so that the connecting member 50 on the upper surface of the unit cell 40 is corroded and the resistance is increased. It is thought that the average power density decreased due to the large voltage drop. Further, in the nickel-hydrogen storage battery 40 of the comparative example, the connecting plate lid 55 is simply fitted and fixed. Therefore, when an external force is applied to the connecting plate lid 55, the connecting plate lid 55 is There is a risk of coming off.
[0026]
On the other hand, in the nickel-hydrogen storage battery 10 according to the embodiment, the poles 13 and 14 are screwed together by using the fastening force of the fixture 30 in which the protective layer 32 is integrally formed by molding. Therefore, even if an external force is applied to the fixture 30, it does not come off. An annular protrusion 33 is disposed on the lower surface of the flange portion 32b of the fixture 30 so as to surround the nut portion 31, and each through hole is formed on the lower surface of the covering layer 24 of the connecting member 20. Since the

annular protrusions

25 and 26 are disposed so as to surround the periphery of the wires 22 and 23, the conductive plate 21 and the pole columns 13 and 14 of the connecting member 20 are corroded even when sprayed with salt water. Absent. For this reason, the voltage drop does not occur in this portion, and the average output density (W / kg) does not decrease.
[0027]
8). Examination of the number of parts Next, the number of parts in the connection part of each battery of the above-described embodiment and comparative example is the number of parts in one connection part, the number of parts in the case of a 10 cell assembled battery, and the set of 10 cells. When the number of parts was calculated when 24 sets of batteries were connected (240 cells (for one EV)), the results shown in Table 2 below were obtained.
[0028]
[Table 2]

[0029]
As is clear from Table 2 above, in the case of the number of parts in one connection part in the case of the embodiment, three parts of one connecting member 20 and two fixing tools 30 are required, and in the case of the comparative example In terms of the number of parts in one connection portion, five parts including one connecting member 50, two

nuts

57, 57 and two connecting

plate lid bodies

55, 55 are required. Therefore, when an assembled battery is formed using 10 cells, 27 parts are required in the case of the example, and 45 parts are required in the case of the comparative example. A set of 240 cells using 12 sets of the assembled battery of 10 cells. A type battery (for one EV) and 648 parts are required in the example, and 1080 parts are required in the comparative example. As described above, when the number of parts can be reduced as in the present embodiment, the number of manufacturing steps can be greatly reduced, so that this type of collective storage battery can be easily manufactured. It can be manufactured at low cost.
[0030]
As described above, in the present invention, the conductive connecting member 20 includes the coating layer 24 on the surface of the metal plate 21 and seals the pole columns 13 and 14 on the surface of the fixture 30 in a liquid-tight and air-tight manner. Since the protective layer 32 to be stopped is provided, the protective layer 32 of the fixing tool 30 is in close contact with the covering layer 24 of the connecting member 20 by screwing the fixing tool 30 to each of the pole columns 13 and 14. Each pole column 13 and 14 is sealed liquid-tight and air-tight. As a result, a highly reliable seal structure can be obtained with a simple structure, and the durability of the connecting member 20 can be improved.
[0031]
Moreover, since the

annular projections

25 and 26 are provided on the contact surface of the cover layer 24 with the cover 16 of the unit cell 10 and the contact surface of the protective layer 32 with the coating layer 24 is provided with the annular projection 33, The space between the layer 24 and the lid 16 of the unit cell 10 and the space between the protective layer 32 and the covering layer 24 are more liquid-tight and air-tight. Furthermore, since the protective layer 32 is integrally formed with the fixing tool 30 by molding, the number of parts is reduced with a simple configuration, and the sealing performance can be easily ensured with fewer steps. The same effect can be obtained by using an annular packing made of the same material as these instead of providing the

annular protrusions

25, 26 and 33.
[0032]
In the above-described embodiment, an example in which chloroprene rubber is used as a constituent material of the coating layer 24 of the connecting member 20 has been described. In addition to chloroprene rubber, synthetic natural rubber, styrene rubber, butadiene rubber, butyl rubber, nitrile rubber, Even when selected from ethylene propylene rubber, acrylic rubber, silicon rubber, polypropylene resin, polyethylene resin, copolymer of polyphenylene ether resin and polystyrene resin, and ABS resin, almost the same results were obtained.
[0033]
In the above-described embodiment, an example in which a polyamide resin is used as a constituent material of the protective layer 32 of the fixture 30 has been described. However, in addition to the polyamide resin, a polypropylene resin, a polyethylene resin, a polyphenylene ether resin, and a polystyrene resin Similar results were obtained even when selected from coalescence or ABS resin.
[0034]
In the above-described embodiment, only the example in which the present invention is applied to the prismatic storage battery has been described. However, the present invention is not limited to the prismatic storage battery, but can be applied to storage batteries having other shapes such as a cylindrical shape and an elliptical shape. Of course. Moreover, although only the example which applies this invention to a nickel hydride storage battery was demonstrated, it cannot be overemphasized that this invention is applicable to various batteries, such as a lithium ion storage battery, a nickel cadmium storage battery, and a lead storage battery. It is.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an external appearance of a unit cell of this embodiment for making a collective alkaline storage battery.
2 is a cross-sectional view showing a cross section of a main part when two unit cells of FIG. 1 are conductively connected.
FIG. 3 is a cross-sectional view showing a main part of a conventional alkaline storage battery (comparative example).
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Nickel-hydrogen storage battery (unit cell), 10a ... Electrode plate group, 11 ... Positive electrode plate, 12 ... Negative electrode plate, 13 ... Positive electrode column, 13a ... Screw part, 14 ... Negative electrode column, 14a ... Screw part, 15 ... Electricity Tank, 16: Lid, 20: Connecting member, 21: Conductive plate, 22: Through hole for positive electrode column, 23: Through hole for negative electrode column, 24 ... Cover layer, 25, 26 ... Annular projection, 30 ... Fixing tool , 31 ... nut part, 32 ... protective layer, 32a ... main body part, 32b ... flange part, 33 ... annular projection

Claims

A power storage element comprising a positive / negative electrode plate, a separator, and an electrolytic solution is a collective storage battery formed by conductively connecting a plurality of unit cells accommodated in a battery case, and the other unit adjacent to the unit cell. The positive poles and the negative poles, which are conductively connected to the unit cells, are provided in the unit cells, and the bipolar columns provided in the unit cells adjacent to each other. A connecting member that selectively conducts conductive connection in accordance with the polarity of the electrode, and a fixing member that fixes the connecting member to each of the pole columns by screwing, and an end portion of each of the pole columns is screwed to the fixing member. The connecting member is composed of a metal plate and a coating layer coated on the surface of the metal plate, and the fixture is a metal nut and a protective layer formed on the surface of the metal nut. It is composed of a coating layer of the connecting member and the protective layer of the fixture Aggregate type storage battery of comprising a sealing layer on the contact surface, the sealing layer is characterized in that said protective layer are integrally formed with an annular projection on the contact surface between the coating layer of the coupling member.

A power storage element comprising a positive / negative electrode plate, a separator, and an electrolytic solution is a collective storage battery formed by conductively connecting a plurality of unit cells accommodated in a battery case, and the other unit adjacent to the unit cell. The positive poles and the negative poles, which are conductively connected to the unit cells, are provided in the unit cells, and the bipolar columns provided in the unit cells adjacent to each other. A connecting member that selectively conducts conductive connection in accordance with the polarity of the electrode, and a fixing member that fixes the connecting member to each of the pole columns by screwing, and an end portion of each of the pole columns is screwed to the fixing member. The connecting member is composed of a metal plate and a coating layer coated on the surface of the metal plate, and the fixture is a metal nut and a protective layer formed on the surface of the metal nut. An annular protrusion is formed on the contact surface of the coating layer with the unit cell. It characterized collecting case storage batteries that have to comprise a.

Construction material of polypropylene resin in the protective layer, a polyethylene resin, a copolymer of a polyphenylene ether resin and polystyrene resin, ABS resin, according to claim 1 or claim, characterized in that it has to select from one of a polyamide resin 2. The collective storage battery according to 2.

The collective storage battery according to claim 1 or 2 , wherein the protective layer is formed integrally with the metal nut by molding.

Aggregate type battery according to claim 1 or claim 2 wherein the protective layer is characterized by hardness is formed by different layers.

The collective storage battery according to claim 1 or 2 , wherein the coating layer is formed integrally with the metal plate by molding.

The coating layer is set storage battery according to claim 1 or claim 2, characterized in that the hardness is formed by different layers.

The coating layer is composed of chloroprene rubber, synthetic natural rubber, styrene rubber, butadiene rubber, butyl rubber, nitrile rubber, ethylene propylene rubber, acrylic rubber, silicone rubber, polypropylene resin, polyethylene resin, polyphenylene ether resin and polystyrene resin. 3. The collective storage battery according to claim 1, wherein the battery is selected from a polymer and an ABS resin.