JP4280349B2

JP4280349B2 - Organic electrolyte secondary battery

Info

Publication number: JP4280349B2
Application number: JP04370999A
Authority: JP
Inventors: 淳浩船橋; 一成大北; 義人近野; 俊之能間; 育郎米津; 晃治西尾
Original assignee: Sanyo Electric Co Ltd
Current assignee: Sanyo Electric Co Ltd
Priority date: 1999-02-22
Filing date: 1999-02-22
Publication date: 2009-06-17
Anticipated expiration: 2019-02-22
Also published as: JP2000243378A

Description

【０００１】
【発明の属する技術分野】
本発明は、電池缶の内部に二次電池要素となる巻き取り電極体を収容して、電池缶に取り付けられた一対の電極端子から二次電池要素の発生電力を取り出すことが可能な有機電解液二次電池に関するものである。
【０００２】
【従来の技術】
電気自動車等の電源や、夜間電力を充電して昼間に放電する電力貯蔵用の電源として用いられる比較的大きな容量の円筒型リチウム二次電池は、図７に示す様に、筒体(11)の両開口部に蓋体(12)(12)を溶接固定して、円筒状の電池缶(１)を形成し、該電池缶(１)の内部に、図６に示す巻き取り電極体(２)を収容して構成されている。
各蓋体(12)には、電極端子機構(９)が取り付けられており、巻き取り電極体(２)と各電極端子機構(９)とが、複数本の集電タブ(３)により互いに接続されて、巻き取り電極体(２)が発生する電力を一対の電極端子機構(９)(９)から外部に取り出すことが可能となっている。又、蓋体(12)には、図６に示す如きバネ復帰式の安全弁(13)が取り付けられている。
【０００３】
巻き取り電極体(２)は、リチウム複合酸化物を含む正極(23)と炭素材料を含む負極(21)の間に、非水電解液が含浸されたセパレータ(22)を介在させて、これらを渦巻き状に巻回して構成されている。
巻き取り電極体(２)の正極(23)及び負極(21)からは夫々複数本の集電タブ(３)が引き出され、極性が同じ複数本の集電タブ(３)の先端部(31)が１つの電極端子機構(９)に接続されている。尚、図６においては、便宜上、一部の集電タブの先端部が電極端子機構(９)に接続されている状態のみを示し、他の集電タブについては、電極端子機構(９)に接続された先端部分の図示を省略している。
【０００４】
電極端子機構(９)は、電池缶(１)の蓋体(12)を貫通して取り付けられたネジ部材(91)を具え、該ネジ部材(91)の基端部には鍔部(92)が形成されている。蓋体(12)の貫通孔には絶縁パッキング(93)が装着され、蓋体(12)と締結部材(91)の間の電気的絶縁性とシール性が保たれている。ネジ部材(91)には、蓋体(12)の外側からワッシャ(94)が嵌められると共に、ナット(95)が螺合している。このナット(95)を締め付けて、ネジ部材(91)の鍔部(92)とワッシャ(94)によって絶縁パッキング(93)を挟圧することにより、シール性を高めている。
前記複数本の集電タブ(３)の先端部(31)は、ネジ部材(91)の鍔部(92)に、スポット溶接或いは超音波溶接によって固定されている。
一対の電極端子機構(９)(９)から電力を取り出す際には、各電極端子機構(９)のネジ部材(91)にリング状の電極板(97)を嵌め、ナット(96)によって電極板(97)を固定すると共に、該電極板(97)に、電流取出し用のリード線(98)の先端部を溶接する。
【０００５】
ところで、上述の如き円筒型二次電池においては、電池缶(１)の蓋体(12)の表面から安全弁(13)が大きく突出した形状となっており、これによって円筒型二次電池の占有空間が大きくなる問題があった。
そこで出願人は、図７に示す様に、圧力開放型の安全弁(５)を装備した円筒型二次電池を提案している。圧力開放型の安全弁(５)は、電池缶(１)の内圧が所定値を越えたときに破れる薄膜を具えて、電池缶(１)の内圧を開放するものである。ここで、蓋体(12)には安全弁(５)のネジ軸部(52)をねじ込むためのネジ孔(15)が開設されている。
該円筒型二次電池によれば、安全弁の蓋体(12)からの突出距離が小さくなって、電池の占有空間が従来よりも縮小される。
【０００６】
【発明が解決しようとする課題】
しかしながら、図７に示す圧力開放型の安全弁(５)を装備した円筒型二次電池においても、電極端子機構(９)が蓋体(12)から大きく突出しているため、依然として、電池の占有空間が大きい問題があった。
【０００７】
又、巻き取り電極体(２)に既定値を超える大きな電流が流れたとき、これを阻止するために、電極端子機構(９)の電流取り出し経路に、正の抵抗温度係数を有する素子(以下、ＰＴＣ素子という)を介在させた二次電池が提案されており(例えば特開平8-293295号)、この様な二次電池においては、ＰＴＣ素子の装備によって更に電極端子機構(９)の突出距離が大きくなって、電池の占有空間が増大する問題があった。
【０００８】
本発明の目的は、電極端子機構にＰＴＣ素子を装備した有機電解液二次電池において、電極端子機構の蓋体からの突出距離を従来よりも短縮することが出来る有機電解液二次電池を提供し、これによって電池の占有空間を従来よりも縮小することである。
【０００９】
【課題を解決する為の手段】
本発明に係る有機電解液二次電池は、筒体(11)の開口部に蓋体(12)が固定されて気密性を有する電池缶(１)の内部に、二次電池要素となる巻き取り電極体(２)を収納して構成され、蓋体(12)に取り付けた電極端子機構(４)によって、巻き取り電極体(２)の発生電力を外部へ取り出すことが出来る。
【００１０】
電極端子機構(４)は、
蓋体(12)の内側に配置されて、蓋体(12)を貫通するネジ軸部(63)を具え、該ネジ軸部(63)の先端部には、ネジ軸部(63)と同軸上に、内ネジ(64)が凹設されている端子部材(６)と、
蓋体(12)から突出する端子部材(６)のネジ軸部(63)に螺合するナット(79)と、
端子部材(６)と蓋体(12)との間に介在して両者の電気的絶縁、並びに気密性を図る第１パッキン部材(66)と、
ナット(79)と蓋体(12)との間に介在して両者の電気的絶縁、並びに気密性を図る第２パッキン部材(70)と、
蓋体(12)の外側に配置されて、端子部材(６)のネジ軸部(63)に凹設された内ネジ(64)に螺合するネジ軸部(72)を具えた締結部材(７)と、
締結部材(７)のネジ軸部(72)が貫通する中央孔(77)を有し、ナット(79)と締結部材(７)の間に挟持されて、端子部材(６)と電気的に接続された板状のＰＴＣ素子(76)と、
ＰＴＣ素子(76)と締結部材(７)の間に挟持されて、ＰＴＣ素子(76)と電気的に接続された電流取出し用リード部材(41)と、
リード部材(41)と締結部材(７)の間に介在して、両者の電気的絶縁を図る絶縁部材(73)
とを具えている。
【００１１】
上記本発明の有機電解液二次電池においては、端子部材(６)に対してナット(79)をねじ込むことによって、これらの部材が蓋体(12)に固定されると共に、端子部材(６)と蓋体(12)との間に第１パッキン部材(66)が挟圧され、ナット(79)と蓋体(12)との間に第２パッキン部材(70)が挟圧されて、気密性が確保される。又、端子部材(６)に対して締結部材(７)をねじ込むことによって、端子部材(６)と締結部材(７)の間に、ＰＴＣ素子(76)、リード部材(41)及び絶縁部材(73)が挟圧されて、これらの部材が蓋体(12)に固定される。
【００１２】
例えば巻き取り電極体(２)からリード部材(41)へ向かって電流が流れる場合、巻き取り電極体(２)から、端子部材(６)及びＰＴＣ素子(76)を経て、リード部材(41)へ至る電流経路が形成される。ここで、端子部材(６)と締結部材(７)とは互いに導通状態となるが、締結部材(７)とリード部材(41)とは、絶縁部材(73)によって互いに絶縁されているので、ＰＴＣ素子(76)を迂回して、端子部材(６)から締結部材(７)を経て直接にリード部材(41)へ流れる電流経路が形成されることはない。
【００１３】
具体的構成においては、端子部材(６)のネジ軸部(63)に螺合するナット(79)を収容する中央孔(81)を有する絶縁キャップ(８)が、素子(76)と蓋体(12)の間に介在して蓋体(12)の表面の全域を覆って配置され、該絶縁キャップ(８)の蓋体(12)との対向面と反対面にＰＴＣ素子(76)が配置されている。該具体的構成によれば、ＰＴＣ素子(76)と蓋体(12)との間に絶縁キャップ(８)が介在しているので、両者間に、確実な電気的絶縁が図られる。
【００１４】
又、具体的構成において、締結部材(７)は、蓋体(12)と対向する多角板部(71)の裏面に前記ネジ軸部(72)を突設して構成され、絶縁部材(73)は、締結部材(７)の多角板部(71)の裏面に接触する円板部(74)と、素子(76)の中央孔(77)を貫通する円筒部(75)とから構成され、該円筒部(75)に、リード部材(41)の端子部(42)が係合して、絶縁部材(73)の円板部(74)とＰＴＣ素子(76)とによって、リード部材(41)の端子部(42)が挟持されている。
該具体的構成においては、絶縁部材(73)の円板部(74)によって締結部材(７)の多角板部(71)とリード部材(41)の端子部(42)との間の電気的絶縁が図られると共に、絶縁部材(73)の円筒部(75)によって、リード部材(41)の端子部(42)並びにＰＴＣ素子(76)と締結部材(７)のネジ軸部(72)との間の電気的絶縁が図られる。
【００１５】
更に具体的な構成においては、端子部材(６)は、蓋体(12)と対向する多角板部(61)の表面に前記ネジ軸部(63)を突設すると共に、多角板部(61)の裏面に第２のネジ軸部(62)を突設して構成され、該第２ネジ軸部(62)には、ナット(65)が螺合して、多角板部(61)とナット(65)とによって、巻き取り電極体(２)から伸びる複数本の集電タブ(３)の先端部(31)が挟持されている。
該具体的構成においては、例えば巻き取り電極体(２)からリード部材(41)へ向かって電流が流れる場合、巻き取り電極体(２)から複数本の集電タブ(３)を経て端子部材(６)の多角板部(61)及び第１ネジ軸部(63)、更にナット(79)を経て、リード部材(41)に至る電流経路が形成される。
【００１６】
【発明の効果】
本発明に係る有機電解液二次電池においては、端子部材(６)のネジ軸部(63)及び締結部材(７)のネジ軸部(72)を除いて、他の構成部材は全て薄型に形成することが可能であり、然も、締結部材(７)のネジ軸部(72)は、端子部材(６)のネジ軸部(63)に凹設した内ネジ(64)にねじ込まれているので、ネジ軸部(72)の長さの一部若しくは大部分は、端子部材(６)のネジ軸部(63)の長さと重複して、重複した長さは、電極端子機構(４)の突出距離に影響を及ぼさない。又、ＰＴＣ素子(76)は、リード部材(41)と一緒に、締結部材(７)と端子部材(６)の間に挟持されて、特別な固定治具は不要である。
これに対し、従来の電極端子機構を具えた有機電解液二次電池においては、電極端子機構自体を蓋体に固定するためのネジ軸部と、リード部材及びＰＴＣ素子を蓋体に固定するためのネジ軸部とが、互いに重なることなく併設されていたため、両ネジ軸部の長さが電極端子機構の突出距離に影響を与え、この結果、電極端子機構の距離が長くなっていた。
従って、本発明に係る有機電解液二次電池によれば、従来よりも電極端子機構の突出距離を少なくとも前記重複距離だけ短縮することが可能であり、これによって電池の占有空間を縮小することが出来る。
【００１７】
【発明の実施の形態】
以下、本発明を円筒型二次電池に実施した例に基づいて更に詳細に説明する。尚、本発明は下記実施例に何ら限定されるものではなく、その要旨を変更しない範囲において適宜変更して実施することが可能なものである。
【００１８】
第１実施例
第１実施例の円筒型二次電池は、図１に示す如く、筒体(11)の各開口部に蓋体(12)を固定してなる電池缶(１)を具え、該電池缶(１)の外径は６４ｍｍ、長さは２９０ｍｍに形成されている。各蓋体(12)には、電池内圧が所定圧力(例えば５ｋｇ／ｃｍ^２)を越えると破れて圧力を開放する圧力開放型の安全弁(５)が２個所に取り付けられている。尚、安全弁(５)は、蓋体(12)に開設されたネジ孔(15)にねじ込んで固定されている。
【００１９】
電池缶(１)の内部には巻き取り電極体(２)が収納されている。巻き取り電極体(２)は、それぞれ帯状に形成された正極(23)と負極(21)の間に、非水電解液が含浸されたセパレータ(22)を介在させて、これらを渦巻き状に巻回して構成されている。
電池缶(１)の一方の蓋体(12)には、本発明に係る電極端子機構(４)が取り付けられると共に、他方の蓋体には図６に示す従来と同一構造の電極端子機構(９)が取り付けられている。
【００２０】
巻き取り電極体(２)の正極(23)及び負極(21)からは夫々複数本の集電タブ(３)が引き出され、図１の如く、負極(21)から伸びる複数本の集電タブ(３)の先端部が、本発明に係る電極端子機構(４)に接続されている。一方、正極(23)から伸びる複数本の集電タブは、従来と同一構造の電極端子機構(９)に接続されている。尚、図１においては、便宜上、一部の集電タブ(３)の先端部が電極端子機構(４)に接続されている状態のみを示し、他の集電タブ(３)については、電極端子機構(４)に接続された先端部分の図示を省略している。
【００２１】
本発明に係る電極端子機構(４)は、図１及び図２に示す如く、蓋体(12)の内側に配置された端子部材(６)と、蓋体(12)の外側に配置されて端子部材(６)にねじ込まれた締結部材(７)とを具え、端子部材(６)と締結部材(７)の間に、第１パッキン部材(66)、第２パッキン部材(70)、ナット(79)、ワッシャ(78)、ＰＴＣ素子(76)、リード部材(41)及び絶縁部材(73)が介在している。
【００２２】
端子部材(６)は、蓋体(12)と対向する多角板部(61)の表面に第１ネジ軸部(63)を上向きに突設すると共に、多角板部(61)の裏面に第２ネジ軸部(62)を下向きに突設して構成されており、第１ネジ軸部(63)の先端部には、第１ネジ軸部(63)と同軸上に、内ネジ(64)が凹設されている。
端子部材(６)の第２ネジ軸部(62)はナット(65)が螺合し、端子部材(６)の多角板部(61)とナット(65)との間に、巻き取り電極体(２)から引き出された複数本の集電タブ(３)の先端部(31)が挟持されている。
【００２３】
締結部材(７)は、蓋体(12)と対向する多角板部(71)の裏面にネジ軸部(72)を突設して構成され、該ネジ軸部(72)が、端子部材(６)の内ネジ(64)にねじ込まれている。
【００２４】
第１パッキン部材(66)は、蓋体(12)の内面の略全域を覆って密着する円板部(67)の表面に、円筒部(68)を上向きに突設してなり、円板部(67)には、安全弁(５)と対応させて、貫通孔(69)が開設されている。第１パッキン部材(66)は、円筒部(68)を蓋体(12)の中央孔(14)に貫通させて、蓋体(12)に取り付けられ、蓋体(12)から突出する円筒部(68)の先端部には、リング状の第２パッキン部材(70)が係合している。
【００２５】
又、端子部材(６)は、第１ネジ軸部(63)を第１パッキン部材(66)の円筒部(68)に貫通させて、蓋体(12)に取り付けられ、第１パッキン部材(66)から突出する第１ネジ軸部(63)の先端部に、ナット(79)が螺合している。
ナット(79)を締め付けることによって、ナット(79)と端子部材(６)の多角板部(61)の間に、第１パッキン部材(66)と第２パッキン部材(70)が挟圧されて、蓋体(12)の中央孔(14)に対する気密性と、端子部材(６)及びナット(79)と蓋体(12)との間の電気的絶縁が図られている。
【００２６】
ナット(79)の表面には、ワッシャ(78)を介して、中央孔(77)を有する円板状のＰＴＣ素子(76)が設置され、ワッシャ(78)及びＰＴＣ素子(76)の中央孔(77)を締結部材(７)のネジ軸部(72)が貫通している。尚、ＰＴＣ素子(76)は、温度が５０℃を越えたとき、電気抵抗が急激に増大して、過電流の発生を抑制するものである。
リード部材(41)は、両端部に端子部(42)(43)を具え、一方の端子部(42)がＰＴＣ素子(76)の表面に設置されている。
【００２７】
絶縁部材(73)は、フッ化樹脂、ポリエチレン、ポリプロピレンなどから形成され、円板部(74)の裏面に円筒部(75)を下向きに突設して構成されており、その中央孔(73a)を締結部材(７)のネジ軸部(72)が貫通している。絶縁部材(73)の円板部(74)は、締結部材(７)の多角板部(71)とリード部材(41)の端子部(42)の間に挟持され、円筒部(75)は、リード部材(41)の端子部(42)及びＰＴＣ素子(76)の中央孔(77)を貫通して、端子部材(６)の第１ネジ軸部(63)の先端面に達している。
【００２８】
端子部材(６)に対して締結部材(７)をねじ込むことによって、ナット(79)と締結部材(７)の多角板部(71)との間に、ワッシャ(78)、ＰＴＣ素子(76)、リード部材(41)の端子部(42)、及び絶縁部材(73)が挟圧されて、これらの部材が蓋体(12)に固定される。又、絶縁部材(73)の円板部(74)によって、締結部材(７)の多角板部(71)とリード部材(41)の端子部(42)との間の電気的絶縁が図られると共に、絶縁部材(73)の円筒部(75)によって、リード部材(41)の端子部(42)並びにＰＴＣ素子(76)と締結部材(７)のネジ軸部(72)との間の電気的絶縁が図られる。
【００２９】
上記電極端子機構(４)を具えた円筒型二次電池においては、蓋体(12)の表面から突出して配置されている複数の部材、即ち、第２パッキン部材(70)、ナット(79)、ワッシャ(78)、ＰＴＣ素子(76)、リード部材(41)の端子部(42)、絶縁部材(73)の円板部(74)、及び締結部材(７)の多角板部(71)が、それぞれ可及的に薄型化されており、然も、軸方向に長い締結部材(７)のネジ軸部(72)と端子部材(６)の第１ネジ軸部(63)とは、互いに長さ方向に重複して、前記複数の薄型部材の厚さ範囲内に収容されている。
【００３０】
従って、電極端子機構(４)の突出距離は従来よりも大幅に短縮され、電池の占有空間が縮小される。
【００３１】
図５は、上記本発明の円筒型二次電池(ａ)と、図７に示す従来の円筒型二次電池(ｂ)の寸法を比較したものであって、本発明の円筒型二次電池では、電極端子機構(４)の蓋体(12)からの突出距離は１０ｍｍと、従来の円筒型二次電池の１５ｍｍよりも短くなっており、これによって、電池の占有空間(突出部分を含む電池全体を収容するための円筒空間)の体積は１.０１Ｌと小さくなる。該従来の円筒型二次電池にＰＴＣ素子を装備すれば(特開平8-293295号)、ＰＴＣ保持機構(99)の装備によって更に突出距離が１５ｍｍだけ増大するので、本発明の円筒型二次電池との差は増大する。
【００３２】
第２実施例
第２実施例の円筒型二次電池においては、図３及び図４に示す如く、蓋体(12)の表面の略全域を覆うことが可能な円板状の絶縁キャップ(８)が、蓋体(12)上に設置されている。絶縁キャップ(８)は中央孔(81)を有して、該中央孔(81)には、蓋体(12)に固定された端子部材(６)のネジ軸部(63)に螺合するナット(79)が収容される。又、絶縁キャップ(８)には、安全弁(５)に対応して貫通孔(82)が開設されている。
そして、絶縁キャップ(８)の表面にＰＴＣ素子(76)が配置されている。その他の構成は、上記第１実施例と同様である。
【００３３】
上記第２実施例の円筒型二次電池においても、電極端子機構(４)の突出距離は第１実施例と同じく、従来よりも大幅に短縮され、電池の占有空間を縮小することが出来る。
又、第２実施例においては、ＰＴＣ素子(76)及びリード部材(41)と蓋体(12)との間に絶縁キャップ(８)が介在しているので、両者間に確実な電気的絶縁が実現される。
【００３４】
次に、上記円筒型二次電池の製造工程について説明する。
正極の作製
正極活物質としてのＬｉＮｉ_０．７Ｃｏ_０．３Ｏ_２と導電剤としての炭素を重量比９０：５で混合して正極合剤を調製した。次に、結着剤であるポリフッ化ビニリデンをＮ−メチル−２−ピロリドン(ＮＭＰ)に溶解させＮＭＰ溶液を調製した。そして、正極合剤とポリフッ化ビニリデンの重量比が９５：５になるように正極合剤とＮＭＰ溶液を混練してスラリーを調製した。このスラリーを正極集電体としてのアルミニウム箔の両面にドクターブレード法により塗布し、１５０℃で２時間の真空乾燥を施して、正極を作製した。
【００３５】
負極の作製
結着剤であるポリフッ化ビニリデンをＮＭＰに溶解させてＮＭＰ溶液を調製し、粒子径１８μｍの天然黒鉛粉末と、粒径１８μｍのコークス粉末とを重量比４：１で混合し、更にこれをポリフッ化ビニリデンの重量比が９０：１０になるように混練してスラリーを調製した。このスラリーを負極集電体としての銅箔の両面にドクターブレード法により塗布し、１５０℃で２時間の真空乾燥を施して負極を作製した。
【００３６】
電解液の調製
エチレンカーボネートとジエチルカーボネートを体積比１：１で混合した溶媒に、ＬｉＰＦ_６を１ｍｏｌ／ｌの割合で溶解して電解液を調製した。
【００３７】
電池の組立
正極を構成しているアルミニウム箔の表面に、厚さ０.１ｍｍのアルミニウム製集電タブを１０本、一定間隔をおいて溶接すると共に、負極を構成している銅箔の表面に、厚さ０.１ｍｍのニッケル製集電タブを１０本、一定間隔をおいて溶接した。そして、正極と負極の間にセパレータを挟んで渦巻き状に巻回し、巻き取り電極体を構成した。尚、セパレータとしては、イオン透過性のポリエチレン製の微多孔性膜を用いた。
この巻き取り電極体を電池缶となる筒体の内部に装填し、該巻き取り電極体から伸びる正側及び負側の集電タブを夫々、蓋体に取り付けられた電極端子機構に接続した後、該蓋体を筒体に溶接固定して、図１及び図２に示す第１実施例の本発明電池Ａ１と、図３及び図４に示す第２実施例の本発明電池Ａ２とを組み立てた。
尚、電池缶は、外径６４ｍｍ、長さ２９０ｍｍであって、その蓋体は、外径６４ｍｍ、厚さ５ｍｍである。負極側の電極端子機構の突出距離は１０ｍｍ、正極側の電極端子機構の突出距離は１５ｍｍである。又、電池の占有空間の体積は１.０１Ｌである。
【００３８】
比較例電池の作製
電極端子機構として図６に示す従来の電極端子機構(９)を用いたこと以外は、上記本発明電池と同様にして、比較例電池Ｘを作製した。
尚、負極側、正極側ともに、電極端子機構の突出距離は１５ｍｍであり、電池の占有空間の体積は、１.０３Ｌである。
【００３９】
性能比較実験
本発明電池と比較例電池の性能を比較するべく、両電池の充放電特性を調べた。実験では、充電率０.１２５Ｃ(９.５Ａ)で８時間の充電を行なった後、放電率０.１２５Ｃで放電終止電圧２.７Ｖまで８時間の放電を行なった。その結果を表１に示す。
【００４０】
【表１】

【００４１】
表１に示す様に、電池の放電容量は、本発明電池Ａ１、Ａ２、及び比較例電池Ｘともに、７６Ａｈであって、平均放電電圧は３.６Ｖ、放電容量は２７３Ｗｈであった。この結果から算出した体積エネルギー密度は、表１に示す様に、比較例電池Ｘでは、２６５Ｗｈ／Ｌであるのに対し、本発明電池Ａ１及びＡ２では、２７０Ｗｈ／Ｌとなり、本発明電池によって、高エネルギー密度化が実現されることが明らかとなった。
【００４２】
上述の如く、本発明に係る電極端子機構(４)を具えた円筒型二次電池によれば、電極端子機構(４)の突出距離を従来よりも短縮して、体積エネルギー密度の高い電池を実現することが出来る。
【図面の簡単な説明】
【図１】本発明に係る第１実施例の二次電池の要部を示す断面図である。
【図２】該二次電池に装備されている電極端子機構の分解斜視図である。
【図３】本発明に係る第２実施例の二次電池の要部を示す断面図である。
【図４】該二次電池に装備されている電極端子機構の分解斜視図である。
【図５】本発明の二次電池(ａ)と従来の二次電池(ｂ)の寸法を比較した図である。
【図６】従来の二次電池の要部を示す断面図である。
【図７】出願人が提案している二次電池の斜視図である。
【符号の説明】
(１) 電池缶
(12) 蓋体
(２) 巻き取り電極体
(３) 集電タブ
(４) 電極端子機構
(41) リード部材
(５) 安全弁
(６) 端子部材
(63) 第１ネジ軸部
(64) 内ネジ
(66) 第１パッキン部材
(70) 第２パッキン部材
(79) ナット
(78) ワッシャ
(76) ＰＴＣ素子
(73) 絶縁部材
(７) 締結部材
(72) ネジ軸部[0001]
BACKGROUND OF THE INVENTION
The present invention provides an organic electrolysis capable of accommodating a wound electrode body serving as a secondary battery element inside a battery can and taking out generated power of the secondary battery element from a pair of electrode terminals attached to the battery can. The present invention relates to a liquid secondary battery.
[0002]
[Prior art]
As shown in FIG. 7, a cylindrical lithium secondary battery having a relatively large capacity used as a power source for an electric vehicle or the like, or a power storage power source for charging nighttime power and discharging it in the daytime, has a cylindrical body (11). The lids (12) and (12) are welded and fixed to both openings to form a cylindrical battery can (1), and the winding electrode body (1) shown in FIG. 2) is accommodated.
An electrode terminal mechanism (9) is attached to each lid (12), and the take-up electrode body (2) and each electrode terminal mechanism (9) are mutually connected by a plurality of current collecting tabs (3). It is possible to take out the electric power generated by the winding electrode body (2) connected to the outside from the pair of electrode terminal mechanisms (9) and (9). A spring return type safety valve (13) as shown in FIG. 6 is attached to the lid (12).
[0003]
The take-up electrode body (2) includes a separator (22) impregnated with a non-aqueous electrolyte between a positive electrode (23) containing a lithium composite oxide and a negative electrode (21) containing a carbon material. Is wound in a spiral shape.
A plurality of current collecting tabs (3) are drawn out from the positive electrode (23) and the negative electrode (21) of the winding electrode body (2), respectively, and the tips (31) of the plurality of current collecting tabs (3) having the same polarity are drawn out. ) Is connected to one electrode terminal mechanism (9). In FIG. 6, for the sake of convenience, only the state where the tip portions of some of the current collecting tabs are connected to the electrode terminal mechanism (9) is shown, and the other current collecting tabs are shown in the electrode terminal mechanism (9). Illustration of the connected tip portion is omitted.
[0004]
The electrode terminal mechanism (9) includes a screw member (91) attached through the lid (12) of the battery can (1), and a hook (92) is provided at the base end of the screw member (91). ) Is formed. An insulating packing (93) is attached to the through hole of the lid (12), and electrical insulation and sealing between the lid (12) and the fastening member (91) are maintained. A washer (94) is fitted to the screw member (91) from the outside of the lid (12), and a nut (95) is screwed. The nut (95) is tightened, and the insulating packing (93) is clamped between the flange (92) and the washer (94) of the screw member (91), thereby improving the sealing performance.
The tip portions (31) of the plurality of current collecting tabs (3) are fixed to the flange portion (92) of the screw member (91) by spot welding or ultrasonic welding.
When electric power is taken out from the pair of electrode terminal mechanisms (9) and (9), a ring-shaped electrode plate (97) is fitted to the screw member (91) of each electrode terminal mechanism (9), and the electrode is formed by the nut (96). While fixing the plate (97), the tip of the lead wire (98) for extracting current is welded to the electrode plate (97).
[0005]
By the way, in the cylindrical secondary battery as described above, the safety valve (13) has a shape that protrudes greatly from the surface of the lid (12) of the battery can (1), thereby occupying the cylindrical secondary battery. There was a problem of increasing the space.
Therefore, the applicant has proposed a cylindrical secondary battery equipped with a pressure relief type safety valve (5) as shown in FIG. The pressure relief type safety valve (5) is provided with a thin film that is broken when the internal pressure of the battery can (1) exceeds a predetermined value to release the internal pressure of the battery can (1). Here, a screw hole (15) for screwing the screw shaft portion (52) of the safety valve (5) is formed in the lid (12).
According to the cylindrical secondary battery, the protruding distance from the lid (12) of the safety valve is reduced, and the occupied space of the battery is reduced as compared with the conventional battery.
[0006]
[Problems to be solved by the invention]
However, even in the cylindrical secondary battery equipped with the pressure relief type safety valve (5) shown in FIG. 7, the electrode terminal mechanism (9) protrudes greatly from the lid (12), so that the space occupied by the battery still remains. There was a big problem.
[0007]
In addition, in order to prevent a large current exceeding a predetermined value from flowing through the take-up electrode body (2), an element having a positive temperature coefficient of resistance (hereinafter referred to as an element having a positive resistance temperature coefficient) is provided in the current extraction path of the electrode terminal mechanism (9). (Referred to as a PTC element) has been proposed (for example, Japanese Patent Laid-Open No. 8-293295). In such a secondary battery, the electrode terminal mechanism (9) protrudes further depending on the equipment of the PTC element. There is a problem that the space is increased and the space occupied by the battery is increased.
[0008]
An object of the present invention is to provide an organic electrolyte secondary battery in which the electrode terminal mechanism is equipped with a PTC element and the protruding distance from the lid of the electrode terminal mechanism can be shortened compared to the conventional one. Thus, the occupied space of the battery is reduced as compared with the conventional case.
[0009]
[Means for solving the problems]
The organic electrolyte secondary battery according to the present invention has a lid (12) fixed to an opening of a cylindrical body (11) and is wound inside a battery can (1) having airtightness to be a secondary battery element. The power generated by the take-up electrode body (2) can be taken out by the electrode terminal mechanism (4) which is configured to house the take-up electrode body (2) and is attached to the lid body (12).
[0010]
The electrode terminal mechanism (4)
The screw shaft portion (63) is disposed inside the lid body (12) and penetrates the lid body (12), and the tip end portion of the screw shaft portion (63) is coaxial with the screw shaft portion (63). A terminal member (6) having a recessed inner screw (64) thereon;
A nut (79) screwed into the screw shaft (63) of the terminal member (6) protruding from the lid (12);
A first packing member (66) interposed between the terminal member (6) and the lid (12) to achieve electrical insulation and airtightness between the two,
A second packing member (70) interposed between the nut (79) and the lid (12) for electrical insulation and airtightness of the two,
A fastening member having a screw shaft portion (72) disposed outside the lid (12) and screwed into an inner screw (64) recessed in the screw shaft portion (63) of the terminal member (6). 7) and
The screw shaft portion (72) of the fastening member (7) has a central hole (77) through which it is sandwiched between the nut (79) and the fastening member (7), and is electrically connected to the terminal member (6). A connected plate-like PTC element (76);
A current extraction lead member (41) sandwiched between the PTC element (76) and the fastening member (7) and electrically connected to the PTC element (76);
Insulating member (73) interposed between the lead member (41) and the fastening member (7) to electrically insulate them.
And has.
[0011]
In the organic electrolyte secondary battery of the present invention, in the this screwing the nut (79) to the terminal member (6) Thus, with these members is fixed to the cover body (12), terminal members ( 6) The first packing member (66) is clamped between the lid (12) and the second packing member (70) is clamped between the nut (79) and the lid (12). Airtightness is ensured. Further, by screwing the fastening member (7) into the terminal member (6), the PTC element (76), the lead member (41) and the insulating member (between the terminal member (6) and the fastening member (7)). 73) is clamped, and these members are fixed to the lid (12).
[0012]
For example, when a current flows from the winding electrode body (2) to the lead member (41), the lead member (41) passes from the winding electrode body (2) through the terminal member (6) and the PTC element (76). A current path leading to is formed. Here, the terminal member (6) and the fastening member (7) are electrically connected to each other, but the fastening member (7) and the lead member (41) are insulated from each other by the insulating member (73). A current path that bypasses the PTC element (76) and flows directly from the terminal member (6) through the fastening member (7) to the lead member (41) is not formed.
[0013]
In a specific configuration, an insulating cap (8) having a central hole (81) for receiving a nut (79) screwed into a screw shaft portion (63) of the terminal member (6) includes an element (76) and a lid. lid interposed between (12) disposed over the entire range of the surface (12), the lid of the insulating cap (8) (12) PTC elements on the facing surface and the opposite surface of the (76) Is arranged. According to this specific configuration, since the insulating cap (8) is interposed between the PTC element (76) and the lid (12), reliable electrical insulation can be achieved between them.
[0014]
Further, in a specific configuration, the fastening member (7) is configured by projecting the screw shaft portion (72) on the back surface of the polygonal plate portion (71) facing the lid (12), and an insulating member (73 ) Is composed of a disc portion (74) that contacts the back surface of the polygonal plate portion (71) of the fastening member (7) and a cylindrical portion (75) that passes through the central hole (77) of the element (76). The terminal portion (42) of the lead member (41) is engaged with the cylindrical portion (75), and the lead portion (74) of the insulating member (73) and the PTC element (76) 41) the terminal part (42) is clamped.
In this specific configuration, electrical connection between the polygonal plate portion (71) of the fastening member (7) and the terminal portion (42) of the lead member (41) is performed by the disc portion (74) of the insulating member (73). Insulation is achieved, and the cylindrical portion (75) of the insulating member (73) is connected to the terminal portion (42) of the lead member (41) and the screw shaft portion (72) of the PTC element (76) and the fastening member (7). Is electrically insulated.
[0015]
In a more specific configuration, the terminal member (6) has the screw shaft portion (63) protruding from the surface of the polygonal plate portion (61) facing the lid (12) and the polygonal plate portion (61). ), And a nut (65) is screwed onto the second screw shaft portion (62) to form a polygonal plate portion (61). The nuts (65) sandwich the tip portions (31) of a plurality of current collecting tabs (3) extending from the winding electrode body (2).
In the specific configuration, for example, when a current flows from the winding electrode body (2) to the lead member (41), the terminal member is passed from the winding electrode body (2) through a plurality of current collecting tabs (3). A current path that reaches the lead member (41) through the polygonal plate portion (61) and the first screw shaft portion (63) and the nut (79) in (6) is formed.
[0016]
【The invention's effect】
In the organic electrolyte secondary battery according to the present invention, all the other components are thin except for the screw shaft portion (63) of the terminal member (6) and the screw shaft portion (72) of the fastening member (7). However, the screw shaft portion (72) of the fastening member (7) is screwed into the internal screw (64) provided in the screw shaft portion (63) of the terminal member (6). Therefore, a part or most of the length of the screw shaft portion (72) overlaps with the length of the screw shaft portion (63) of the terminal member (6), and the overlapped length is determined by the electrode terminal mechanism (4 ) Does not affect the protruding distance. Further, the PTC element (76) is sandwiched between the fastening member (7) and the terminal member (6) together with the lead member (41), and no special fixing jig is required.
On the other hand, in an organic electrolyte secondary battery having a conventional electrode terminal mechanism, a screw shaft for fixing the electrode terminal mechanism itself to the lid, and the lead member and the PTC element are fixed to the lid. Therefore, the length of both screw shafts affects the protruding distance of the electrode terminal mechanism, and as a result, the distance of the electrode terminal mechanism is increased.
Therefore, according to the organic electrolyte secondary battery according to the present invention, it is possible to reduce the protruding distance of the electrode terminal mechanism by at least the overlapping distance as compared with the conventional case, thereby reducing the occupied space of the battery. I can do it.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail based on an example in which the present invention is applied to a cylindrical secondary battery. In addition, this invention is not limited to the following Example at all, In the range which does not change the summary, it can change suitably and can implement.
[0018]
1. First embodiment A cylindrical secondary battery according to a first embodiment has a battery can (1) in which a lid (12) is fixed to each opening of a cylindrical body (11) as shown in FIG. The battery can (1) has an outer diameter of 64 mm and a length of 290 mm. Each lid (12) is provided with ^two pressure relief type safety valves (5) that are torn and release the pressure when the battery internal pressure exceeds a predetermined pressure (for example, 5 kg / cm ² ). The safety valve (5) is fixed by screwing into a screw hole (15) formed in the lid (12).
[0019]
The winding electrode body (2) is accommodated in the battery can (1). The take-up electrode body (2) is spirally formed by interposing a separator (22) impregnated with a non-aqueous electrolyte between a positive electrode (23) and a negative electrode (21) each formed in a strip shape. It is composed by winding.
An electrode terminal mechanism (4) according to the present invention is attached to one lid (12) of the battery can (1), and an electrode terminal mechanism (with the same structure as the conventional one shown in FIG. 6) is attached to the other lid. 9) is attached.
[0020]
A plurality of current collecting tabs (3) are drawn from the positive electrode (23) and the negative electrode (21) of the winding electrode body (2), and a plurality of current collecting tabs extending from the negative electrode (21) as shown in FIG. The tip of (3) is connected to the electrode terminal mechanism (4) according to the present invention. On the other hand, a plurality of current collecting tabs extending from the positive electrode (23) are connected to the electrode terminal mechanism (9) having the same structure as the conventional one. In FIG. 1, for the sake of convenience, only the state in which the tip ends of some of the current collecting tabs (3) are connected to the electrode terminal mechanism (4) is shown. The illustration of the tip portion connected to the terminal mechanism (4) is omitted.
[0021]
As shown in FIGS. 1 and 2, the electrode terminal mechanism (4) according to the present invention includes a terminal member (6) disposed inside the lid (12) and an outer side of the lid (12). A fastening member (7) screwed into the terminal member (6), and a first packing member (66), a second packing member (70), and a nut between the terminal member (6) and the fastening member (7). (79), a washer (78), a PTC element (76), a lead member (41) and an insulating member (73) are interposed.
[0022]
The terminal member (6) has a first screw shaft portion (63) projecting upward on the surface of the polygonal plate portion (61) facing the lid (12), and a second member on the back surface of the polygonal plate portion (61). Two screw shafts (62) project downward, and the first screw shaft (63) has an inner screw (64) coaxially with the first screw shaft (63) at the tip. ) Is recessed.
A nut (65) is screwed into the second screw shaft portion (62) of the terminal member (6), and the winding electrode body is disposed between the polygonal plate portion (61) and the nut (65) of the terminal member (6). The tip end portions (31) of the plurality of current collecting tabs (3) drawn from (2) are clamped.
[0023]
The fastening member (7) is configured by projecting a screw shaft portion (72) on the back surface of the polygonal plate portion (71) facing the lid (12), and the screw shaft portion (72) is formed by a terminal member ( It is screwed into the inner screw (64) of 6).
[0024]
The first packing member (66) is formed by projecting a cylindrical portion (68) upward on the surface of a disc portion (67) that covers and substantially adheres to the entire inner surface of the lid (12). A through hole (69) is formed in the part (67) in correspondence with the safety valve (5). The first packing member (66) is a cylindrical portion that is attached to the lid (12) and protrudes from the lid (12) by passing the cylindrical portion (68) through the central hole (14) of the lid (12). A ring-shaped second packing member (70) is engaged with the tip of (68).
[0025]
The terminal member (6) is attached to the lid (12) by passing the first screw shaft portion (63) through the cylindrical portion (68) of the first packing member (66), and the first packing member ( The nut (79) is screwed into the tip of the first screw shaft (63) protruding from 66).
By tightening the nut (79), the first packing member (66) and the second packing member (70) are sandwiched between the nut (79) and the polygonal plate portion (61) of the terminal member (6). The airtightness of the lid (12) with respect to the central hole (14) and the electrical insulation between the terminal member (6) and the nut (79) and the lid (12) are achieved.
[0026]
A disc-shaped PTC element (76) having a central hole (77) is installed on the surface of the nut (79) via a washer (78), and the central holes of the washer (78) and the PTC element (76) are installed. The screw shaft portion (72) of the fastening member (7) passes through (77). The PTC element (76) suppresses the occurrence of overcurrent when the temperature exceeds 50 ° C. and the electrical resistance increases rapidly.
The lead member (41) has terminal portions (42) and (43) at both ends, and one terminal portion (42) is installed on the surface of the PTC element (76).
[0027]
The insulating member (73) is made of a fluororesin, polyethylene, polypropylene, etc., and is configured by projecting a cylindrical portion (75) downward on the back surface of the disc portion (74), and a central hole (73a ) Through the screw shaft portion (72) of the fastening member (7). The disc part (74) of the insulating member (73) is sandwiched between the polygonal plate part (71) of the fastening member (7) and the terminal part (42) of the lead member (41), and the cylindrical part (75) is The lead member (41) passes through the terminal portion (42) and the central hole (77) of the PTC element (76) and reaches the tip surface of the first screw shaft portion (63) of the terminal member (6). .
[0028]
By screwing the fastening member (7) into the terminal member (6), a washer (78) and a PTC element (76) are provided between the nut (79) and the polygonal plate portion (71) of the fastening member (7). Then, the terminal portion (42) of the lead member (41) and the insulating member (73) are clamped, and these members are fixed to the lid (12). Further, electrical insulation between the polygonal plate portion (71) of the fastening member (7) and the terminal portion (42) of the lead member (41) is achieved by the disc portion (74) of the insulating member (73). At the same time, the cylindrical portion (75) of the insulating member (73) causes the terminal portion (42) of the lead member (41) and the electricity between the PTC element (76) and the screw shaft portion (72) of the fastening member (7). Insulation is achieved.
[0029]
In the cylindrical secondary battery having the electrode terminal mechanism (4), a plurality of members arranged to protrude from the surface of the lid (12), that is, a second packing member (70), a nut (79) , Washer (78), PTC element (76), terminal part (42) of lead member (41), disk part (74) of insulating member (73), and polygonal plate part (71) of fastening member (7) However, the screw shaft portion (72) of the fastening member (7) that is long in the axial direction and the first screw shaft portion (63) of the terminal member (6) are each made as thin as possible. The plurality of thin members overlap each other in the length direction and are accommodated within the thickness range of the plurality of thin members.
[0030]
Therefore, the protruding distance of the electrode terminal mechanism (4) is significantly shortened compared to the conventional case, and the space occupied by the battery is reduced.
[0031]
FIG. 5 shows a comparison of the dimensions of the cylindrical secondary battery (a) of the present invention and the conventional cylindrical secondary battery (b) shown in FIG. Then, the protruding distance of the electrode terminal mechanism (4) from the lid (12) is 10 mm, which is shorter than 15 mm of the conventional cylindrical secondary battery, and thereby the occupied space of the battery (including the protruding portion). The volume of the cylindrical space for accommodating the entire battery is as small as 1.01L. If the conventional cylindrical secondary battery is equipped with a PTC element (Japanese Patent Laid-Open No. 8-293295), the projection distance is further increased by 15 mm by the provision of the PTC holding mechanism (99). The difference with the battery increases.
[0032]
Second embodiment In the cylindrical secondary battery of the second embodiment, as shown in Figs. 3 and 4, a disk-shaped battery that can cover substantially the entire surface of the lid (12). An insulating cap (8) is installed on the lid (12). The insulating cap (8) has a central hole (81), and the central hole (81) is screwed into the screw shaft (63) of the terminal member (6) fixed to the lid (12). A nut (79) is received. The insulating cap (8) has a through hole (82) corresponding to the safety valve (5).
A PTC element (76) is disposed on the surface of the insulating cap (8). Other configurations are the same as those in the first embodiment.
[0033]
Also in the cylindrical secondary battery of the second embodiment, the protruding distance of the electrode terminal mechanism (4) is significantly shortened compared with the first embodiment, and the occupied space of the battery can be reduced.
In the second embodiment, since the insulating cap (8) is interposed between the PTC element (76) and the lead member (41) and the lid (12), reliable electrical insulation is provided between them. Is realized.
[0034]
Next, the manufacturing process of the cylindrical secondary battery will be described.
Production of positive electrode A positive electrode mixture was prepared by mixing LiNi _0.7 Co _0.3 O ₂ as a positive electrode active material and carbon as a conductive agent in a weight ratio of 90: 5. Next, an NMP solution was prepared by dissolving polyvinylidene fluoride as a binder in N-methyl-2-pyrrolidone (NMP). Then, the positive electrode mixture and the NMP solution were kneaded so that the weight ratio of the positive electrode mixture and polyvinylidene fluoride was 95: 5 to prepare a slurry. This slurry was applied to both surfaces of an aluminum foil as a positive electrode current collector by a doctor blade method, and vacuum dried at 150 ° C. for 2 hours to produce a positive electrode.
[0035]
Preparation of negative electrode Polyvinylidene fluoride as a binder was dissolved in NMP to prepare an NMP solution. A natural graphite powder having a particle size of 18 μm and a coke powder having a particle size of 18 μm were mixed at a weight ratio of 4: 1. These were mixed and further kneaded so that the weight ratio of polyvinylidene fluoride was 90:10 to prepare a slurry. This slurry was applied to both surfaces of a copper foil as a negative electrode current collector by a doctor blade method, and vacuum dried at 150 ° C. for 2 hours to produce a negative electrode.
[0036]
Volume ratio Preparation <br/> ethylene carbonate and diethyl carbonate electrolyte 1: mixed solvent at 1, the electrolytic solution was prepared by dissolving LiPF ₆ at a rate of 1 mol / l.
[0037]
Battery assembly Ten aluminum current collecting tabs with a thickness of 0.1 mm are welded at regular intervals to the surface of the aluminum foil constituting the positive electrode, and the copper constituting the negative electrode is formed. Ten nickel current collecting tabs with a thickness of 0.1 mm were welded to the surface of the foil at regular intervals. Then, a separator was sandwiched between the positive electrode and the negative electrode and wound in a spiral shape to form a wound electrode body. As the separator, an ion-permeable polyethylene microporous membrane was used.
After loading this take-up electrode body into a cylindrical body that becomes a battery can, and connecting the positive and negative current collecting tabs extending from the take-up electrode body to an electrode terminal mechanism attached to the lid, respectively. The lid is welded and fixed to the cylindrical body to assemble the inventive battery A1 of the first embodiment shown in FIGS. 1 and 2 and the inventive battery A2 of the second embodiment shown in FIGS. It was.
The battery can has an outer diameter of 64 mm and a length of 290 mm, and the lid body has an outer diameter of 64 mm and a thickness of 5 mm. The protruding distance of the electrode terminal mechanism on the negative electrode side is 10 mm, and the protruding distance of the electrode terminal mechanism on the positive electrode side is 15 mm. The volume of the occupied space of the battery is 1.01L.
[0038]
Production of comparative battery A comparative battery X was produced in the same manner as the battery of the present invention except that the conventional electrode terminal mechanism (9) shown in Fig. 6 was used as the electrode terminal mechanism.
Note that, on both the negative electrode side and the positive electrode side, the protruding distance of the electrode terminal mechanism is 15 mm, and the volume of the occupied space of the battery is 1.03 L.
[0039]
Performance comparison experiment In order to compare the performance of the battery of the present invention and the comparative battery, the charge / discharge characteristics of both batteries were examined. In the experiment, after charging for 8 hours at a charging rate of 0.125 C (9.5 A), discharging was performed for 8 hours to a final discharge voltage of 2.7 V at a discharging rate of 0.125 C. The results are shown in Table 1.
[0040]
[Table 1]

[0041]
As shown in Table 1, the discharge capacity of the batteries was 76 Ah for the batteries A1 and A2 of the present invention and the comparative battery X, the average discharge voltage was 3.6 V, and the discharge capacity was 273 Wh. As shown in Table 1, the volume energy density calculated from this result is 265 Wh / L for the comparative battery X, whereas it is 270 Wh / L for the batteries A1 and A2 of the present invention. It became clear that high energy density was realized.
[0042]
As described above, according to the cylindrical secondary battery including the electrode terminal mechanism (4) according to the present invention, the protruding distance of the electrode terminal mechanism (4) is shortened compared with the conventional battery, and a battery with a high volume energy density is obtained. Can be realized.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a main part of a secondary battery according to a first embodiment of the present invention.
FIG. 2 is an exploded perspective view of an electrode terminal mechanism provided in the secondary battery.
FIG. 3 is a cross-sectional view showing a main part of a secondary battery according to a second embodiment of the present invention.
FIG. 4 is an exploded perspective view of an electrode terminal mechanism equipped in the secondary battery.
FIG. 5 is a diagram comparing dimensions of a secondary battery (a) of the present invention and a conventional secondary battery (b).
FIG. 6 is a cross-sectional view showing a main part of a conventional secondary battery.
FIG. 7 is a perspective view of a secondary battery proposed by the applicant.
[Explanation of symbols]
(1) Battery can
(12) Lid
(2) Winding electrode body
(3) Current collection tab
(4) Electrode terminal mechanism
(41) Lead member
(5) Safety valve
(6) Terminal material
(63) First screw shaft
(64) Internal screw
(66) First packing member
(70) Second packing member
(79) Nut
(78) Washer
(76) PTC element
(73) Insulating material
(7) Fastening member
(72) Screw shaft

Claims

The lid (12) is fixed to the opening of the cylindrical body (11), and the wound battery electrode (2) serving as the secondary battery element is housed in the airtight battery can (1). In the organic electrolyte secondary battery in which the electric power generated by the take-up electrode body (2) can be taken out by the electrode terminal mechanism (4) attached to the lid (12), the electrode terminal mechanism (4)
The screw shaft portion (63) is disposed inside the lid body (12) and penetrates the lid body (12), and the tip end portion of the screw shaft portion (63) is coaxial with the screw shaft portion (63). A terminal member (6) having a recessed inner screw (64) thereon;
A nut (79) screwed into the screw shaft (63) of the terminal member (6) protruding from the lid (12);
A first packing member (66) interposed between the terminal member (6) and the lid (12) to achieve electrical insulation and airtightness between the two,
A second packing member (70) interposed between the nut (79) and the lid (12) for electrical insulation and airtightness of the two,
A fastening member having a screw shaft portion (72) disposed outside the lid (12) and screwed into an inner screw (64) recessed in the screw shaft portion (63) of the terminal member (6). 7) and
The screw shaft portion (72) of the fastening member (7) has a central hole (77) through which it is sandwiched between the nut (79) and the fastening member (7), and is electrically connected to the terminal member (6). A plate-like element (76) having a positive resistance temperature coefficient connected thereto;
A current extraction lead member (41) sandwiched between the element (76) and the fastening member (7) and electrically connected to the element (76);
Insulating member (73) interposed between the lead member (41) and the fastening member (7) to electrically insulate them.
An organic electrolyte secondary battery characterized by comprising:

An insulating cap (8) having a central hole (81) for receiving a nut (79) screwed into the screw shaft (63) of the terminal member (6 ) is interposed between the element (76) and the lid (12). interposed are arranged over the entire range of the surface of the lid (12), claim the element on the opposite surface and the opposite surface of the lid of the insulating cap (8) (12) (76) is arranged 2. The organic electrolyte secondary battery according to 1.

The fastening member (7) is formed by projecting the screw shaft portion (72) on the back surface of the polygonal plate portion (71) facing the lid (12), and the insulating member (73) is formed by the fastening member (7). ) Of the polygonal plate portion (71) and the cylindrical portion (75) penetrating the central hole (77) of the element (76), the cylindrical portion (75) The terminal portion (42) of the lead member (41) is engaged with the disk portion (74) of the insulating member (73) and the element (76). The organic electrolyte secondary battery according to claim 1 or 2, wherein is sandwiched.

The terminal member (6) has the screw shaft portion (63) protruding from the surface of the polygonal plate portion (61) facing the lid (12) and the second screw on the back surface of the polygonal plate portion (61). A shaft portion (62) is provided so as to project, and a nut (65) is screwed onto the second screw shaft portion (62), and is wound by the polygonal plate portion (61) and the nut (65). The organic electrolyte secondary battery according to any one of claims 1 to 3, wherein tip portions (31) of a plurality of current collecting tabs (3) extending from the collecting electrode body (2) are sandwiched.