JP4099609B2

JP4099609B2 - battery

Info

Publication number: JP4099609B2
Application number: JP25339098A
Authority: JP
Inventors: 剛文井上
Original assignee: GS Yuasa Corp
Current assignee: GS Yuasa Corp
Priority date: 1998-09-08
Filing date: 1998-09-08
Publication date: 2008-06-11
Anticipated expiration: 2018-09-08
Also published as: JP2000082486A

Description

【０００１】
【発明の属する技術分野】
本発明は、帯状の正負の電極を帯状のセパレータを介して巻回した巻回型の発電要素を備えた電池に関する。
【０００２】
【従来の技術】
長円筒形の巻回型の発電要素１を備えた非水電解質二次電池の構成例を図５に示す。この発電要素１は、帯状の負極１ａと正極１ｂを帯状のセパレータ１ｃを介して長円筒形に巻回して構成したものであり、負極１ａと正極１ｂをそれぞれ上下に少しずつずらして巻回することにより、発電要素１の上端側には負極１ａの上方端縁部のみを突出させ、下端側には正極１ｂの下方端縁部のみを突出させている。この際、負極１ａは上方端縁部に活物質を塗布せず、正極１ｂは下方端縁部に活物質を塗布しないようにして、それぞれ発電要素１の上下端にはこれら負極１ａと正極１ｂの金属箔を露出させるようにする。また、セパレータ１ｃは、これら負極１ａと正極１ｂが重なり合う部分は確実に覆うが、上下の端縁部は覆わないような幅で巻回する。
【０００３】
上記非水電解質二次電池は、従来図６に示すような負極集電体２を発電要素１の上端部に配置して負極１ａの集電を行っていた。負極集電体２は、銅板からなり、発電要素１の上端部の中央片側の上方に集電部２ａが形成されると共に、この集電部２ａから平板状の端子接続部２ｂを引き出して発電要素１の上端部の片方の半円部の上方に配置したものである。集電部２ａは、銅板を蛇腹状に繰り返し屈曲させて、上方に突出する挟持部２ｃと下方に突出する押込部２ｅとを形成したものである。挟持部２ｃは、頂部で折り返した垂直な２枚の銅板がわずかな間隔を開けて向かい合わせに配置されるようにしたものであり、押込部２ｅは、底部で折り返した傾斜した２枚の銅板が徐々に間隔を広げて断面Ｖ字形状となった部分である。
【０００４】
上記負極集電体２は、図７に示すように、発電要素１の上端に突出する負極１ａの端縁部を集電部２ａの各挟持部２ｃの隙間に複数枚ずつまとめて挟み込んでかしめると共に超音波溶接によって接続固定する。この際、集電部２ａは、上方から発電要素１の上端部に押し下げることにより、押込部２ｅの下方に突出する先端を負極１ａの上端縁部の間に押し込み、断面Ｖ字形状の両側の傾斜面でこれら負極１ａの上端縁部を振り分けてそれぞれ挟持部２ｃの隙間に導き入れることになる。
【０００５】
また、この発電要素１の下端部には、図８に示すような正極集電体３を配置して正極１ｂの集電を行っていた。正極集電体３は、負極集電体２と同様の構造の集電部３ａを有するものであるが、銅板に代えてアルミニウム板が用いられる。この正極集電体３は、発電要素１の下端に突出する正極１ｂの端縁部を集電部３ａの挟持部３ｃの隙間に挟み込んでかしめと超音波溶接によって接続固定するようになっている。この際、集電部３ａの押込部３ｅが正極１ｂの端縁部を振り分けて挟持部３ｃの隙間に導き入れるのは同じである。しかし、ここでは、端子接続部３ｂが発電要素１の上端部の上方にまで引き出される場合の例を示す。もっとも、正極端子５を発電要素１の下方から突出させる場合には、この端子接続部３ｂも発電要素１の下端部の下方に配置されることになる。
【０００６】
なお、図面では簡単のため、発電要素１の負極１ａや正極１ｂ等を少ない巻き数で粗く巻回して示しているが、実際は極めて密に多くの巻き数で巻回するので、集電部２ａ，３ａの各挟持部２ｃ，３ｃの隙間には負極１ａや正極１ｂの端縁部がそれぞれ多数枚ずつ挟み込まれて接続固定される。また、これら負極集電体２や正極集電体３の集電部２ａ，３ａは、発電要素１の中央片側のみならず、中央の両側の上方や下方に配置して集電効率を向上させるようにする場合もある。
【０００７】
【発明が解決しようとする課題】
ところが、上記発電要素１の負極１ａや正極１ｂは、上下の端縁部に銅やアルミニウム等の極めて薄い金属箔が露出するので、実際に集電部２ａ，３ａの押込部２ｅ，３ｅの先端をこれら負極１ａや正極１ｂの端縁部の間に押し込まれると、断面Ｖ字形状の両側の傾斜面で引っ掛かって、シワが寄ったり破断したりするため、挟持部２ｃ，３ｃの隙間にスムーズに導き入れることができないという問題があった。
【０００８】
また、このように集電部２ａ，３ａに押込部２ｅ，３ｅが設けられていると、この押込部２ｅ，３ｅの先端が発電要素１の内部に突入されるので、集電を行わない側の正極１ｂ又は負極１ａと接触して短絡を起こしたり、活物質の塗工面積が狭くなって電池容量が減少するという問題があった。例えば、図９に示すように、負極１ａを集電部２ａの挟持部２ｃに接続固定する場合、下方にずらして配置した正極１ｂの上端が押込部２ｅの先端に接近するので、これらが接触して短絡を起こすおそれが生じる。そして、これを防止するために負極１ａと正極１ｂのずれの量を大きくすると、活物質の未塗工部を広くしなければならないので、その分だけ塗工面積が狭くなって電池容量が減少することになる。
【０００９】
なお、負極１ａや正極１ｂの端縁部がスムーズに挟持部２ｃ，３ｃの隙間に挿入できないという問題については、摩擦係数が小さく滑りの良い素材を用いた、押込部２ｅ，３ｅよりも先端の角度が小さくて長いＶ字形状の歯を有する櫛状の治具を発電要素１の上端部と下端部に押し込んで、事前に負極１ａや正極１ｂの上下の端縁部を挟持部２ｃ，３ｃの隙間に対応する位置に振り分けておき、ここに負極集電体２や正極集電体３の集電部２ａ，３ａを挿入するようにすれば解消することができる。しかし、この場合にも、押込部２ｅ，３ｅの先端が短絡を起こしたり、活物質の塗工面積が狭くなるという問題は解消できなかった。
【００１０】
本発明は、かかる事情に対処するためになされたものであり、平板状の金属板に直接挟持部を設けることにより、電極との短絡が生じるおそれがなく、活物質の塗工面積も広げることができる電池を提供することを目的としている。
【００１１】
【課題を解決するための手段】
請求項１の電池は、一枚の金属板を曲げ加工することによって、複数の箇所に挟持部を形成するとともに、これらの挟持部の間にそれぞれ平板部が設けられた集電部と、集電部の一端から挟持部の上端部以上の高さまで持ち上げられた、水平な板状の端子接続部とを有する集電体を備え、集電部が、帯状の正負の電極をそれぞれ上下の巻回軸方向にずらして帯状のセパレータを介し巻回した巻回型の発電要素の上端部に配置されると共に、この発電要素の上端部に突出する正負いずれかの電極の端縁部が集電部の最寄りの挟持部に挟み込まれて接続固定されたことを特徴とする。
【００１２】
請求項１の発明によれば、電極の端縁部を接続固定する複数の挟持部が平板状の平板部を介して繋がるので、この部分が発電要素の内部に突入するようなことがなくなる。このため、挟持部に接続固定されない側の電極が集電部に接触して短絡を起こすようなおそれがなくなる。また、このため、正負の電極を巻回する際のずれの量を少なくすることができるので、活物質を塗工する面積を広げて電池容量を増大させることもできる。
【００１３】
請求項２の電池は、前記電極の端縁部が、集電部の挟持部に挟み込まれてかしめられると共に、超音波溶接によりこの挟持部に接続固定されたことを特徴とする。
【００１４】
請求項２の発明によれば、電極の端縁部を集電部の挟持部にかしめと超音波溶接により確実に接続固定することができる。
【００１５】
【発明の実施の形態】
以下、本発明の実施形態について図面を参照して説明する。
【００１６】
図１〜図４は本発明の一実施形態を示すものであって、図１は発電要素に接続固定した負極集電体を示す斜視図、図２は発電要素に接続固定する負極集電体と正極集電体の構成を示す斜視図、図３は発電要素の上端に突出する負極の端縁部を振り分けるための治具を示す斜視図、図４は集電部の挟持部に負極の端縁部が挟み込まれた状態を示す部分拡大図である。なお、図５〜図９に示した従来例と同様の機能を有する構成部材には同じ番号を付記する。
【００１７】
本実施形態は、電気自動車等に用いられる長円筒形に巻回した発電要素１を備えた非水電解質二次電池について説明する。この非水電解質二次電池の発電要素１は、図５に示したように、負極１ａと正極１ｂをそれぞれ上下方向（巻回軸方向）に少しずつずらして巻回することにより、この発電要素１の上端側には負極１ａの上方端縁部のみを突出させ、下端側には正極１ｂの下方端縁部のみを突出させたものである。負極１ａは、帯状の銅箔の表面にグラファイト等の負極活物質を塗布したものであり、正極１ｂは、帯状のアルミニウム箔の表面にリチウムコバルト複合酸化物等の正極活物質を塗布したものである。ただし、負極１ａは、上方端縁部を除いた部分にのみ負極活物質を塗布し、正極１ｂは、下方端縁部を除いた部分にのみ正極活物質を塗布しておくことにより、それぞれ発電要素１の上下端には銅箔とアルミニウム箔を露出させて突出させるようにする。セパレータ１ｃは、帯状の微多孔性樹脂フィルムを用い、これら負極１ａと正極１ｂが重なり合う部分は確実に覆うが、上下の端縁部は覆わないような幅で巻回する。
【００１８】
上記発電要素１には、図２に示すような負極集電体２と正極集電体３が接続される。負極集電体２は、銅板をプレス加工したものであり、発電要素１の上端部の中央片側の上方に集電部２ａが配置される。集電部２ａは、この負極集電体２の銅板を曲げ加工することにより、３箇所に挟持部２ｃを形成すると共に、これらの挟持部２ｃの間にそれぞれ平板部２ｄを設けたものである。挟持部２ｃは、水平の平板状の銅板を上方に屈曲させて頂部で折り返すことにより、２枚の銅板を向かい合わせに立設させた部分である。そして、この向かい合わせに立設された２枚の銅板の間には、下方に開口する隙間が設けられる。平板部２ｄは、これら挟持部２ｃの隣接するもの同士をそれぞれ下端部で繋ぐ水平な平板状の部分であり、各挟持部２ｃの間にある程度間隔が開くようにするために設けられる。
【００１９】
上記負極集電体２における集電部２ａの一端は、挟持部２ｃの上端部以上の高さまで持ち上げられて、発電要素１の上端部の片方の半円部の上方まで引き出され、水平な平板状の端子接続部２ｂに繋がっている。この端子接続部２ｂには、負極端子４の下端部がかしめによって接続固定されている。また、上記正極集電体３は、アルミニウム板をプレス加工したものであり、負極集電体２と同様の構成であり上下が逆になった集電部３ａが形成されている。そして、この集電部３ａの一端は、発電要素１の側面に沿って上端部の他方の半円部の上方まで引き出され、水平な平板状の端子接続部３ｂに繋がっている。そして、この端子接続部３ｂには、正極端子５の下端部がかしめによって接続固定されている。
【００２０】
上記発電要素１は、まず図３に示すように、下向きのＶ字形状の歯が形成された櫛状の治具６を上端部の中央片側に挿入することにより、この発電要素１の上端に突出する負極１ａの端縁部を３箇所に振り分けて集める。治具６は、高密度ポリエチレンのように硬度の高い素材を用いると共に、歯の先端の角度を小さくしてＶ字形状を長くすることにより、負極１ａの端縁部に露出した薄い銅箔にシワを寄せたり破断させることなく、これらをスムーズに振り分けることができる。
【００２１】
次に、図１に示すように、発電要素１の上端部に負極集電体２を載置して、治具６によって振り分けられた複数枚ずつの負極１ａの端縁部を集電部２ａの各挟持部２ｃの隙間にそれぞれ挟み込む。負極１ａの端縁部が各挟持部２ｃに挟み込まれると、治具６は外される。そして、各挟持部２ｃの２枚の銅板をかしめると共に超音波溶接を行うことにより、これらの挟持部２ｃに挟み込まれた負極１ａの端縁部の銅箔が露出した部分を集電部２ａに接続固定する。かしめ作業は、各挟持部２ｃの両側にかしめ工具のアタッチメントを上方から挿入し、２枚の銅板を押し潰すように力を加えることにより行われる。また、超音波溶接は、各挟持部２ｃの両側に超音波溶接器のアタッチメントを上方から挿入し、２枚の銅板に超音波振動を加えることにより行われる。平板部２ｄは、隣接する挟持部２ｃの間にこれらのアタッチメントを挿入する空間を提供するために、上記のようにある程度の間隔が開くように設けられる。なお、図面では簡単のため、発電要素１の負極１ａや正極１ｂ等を少ない巻き数で粗く巻回して示しているが、実際は極めて密に多くの巻き数で巻回するので、集電部２ａの各挟持部２ｃの隙間には負極１ａの端縁部がそれぞれ多数枚ずつ挟み込まれて接続固定される。
【００２２】
また、正極集電体３も、負極集電体２と同様に、発電要素１の下端に突出する正極１ｂの端縁部のアルミニウム箔が露出した部分を集電部３ａの挟持部３ｃの隙間に複数枚ずつまとめて挟み込んでかしめると共に超音波溶接によって接続固定する。なお、この集電部３ａから上端部に引き出された正極集電体３の端子接続部３ｂは、負極集電体２の集電部２ａの上方に重ねて配置されることになるが、これらの間には絶縁材が挿入されて短絡を防止するようになっている。
【００２３】
上記負極集電体２と正極集電体３を接続固定した発電要素１は、図示しない長円筒形の電池ケースに収納されて非水電解液を注入され密閉されることにより非水電解質二次電池となる。また、負極端子４と正極端子５は、それぞれ絶縁封止されて電池の上部から突設される。
【００２４】
上記構成によれば、負極１ａや正極１ｂの端縁部を接続固定する複数の挟持部２ｃ，３ｃがそれぞれ平板状の平板部２ｄ，３ｄを介して繋がり、この平板部２ｄ，３ｄが発電要素１の内部に突入するようなことがないので、短絡のおそれがなくなると共に、電池容量を増大させることができるようになる。例えば、図４に示すように、負極１ａを集電部２ａの挟持部２ｃに接続固定する場合、下方にずらして配置した正極１ｂの上端と平板状の平板部２ｄの裏面との間には十分な距離が保たれるので、これらが接触して短絡を起こすようなおそれが生じない。また、このように正極１ｂの上端と平板状の平板部２ｄの裏面との間が十分に離れていれば、負極１ａと正極１ｂのずれの量を少なくしても短絡のおそれがなくなるので、活物質の未塗工部を狭くしてその分だけ塗工面積を広げ電池容量を増大させることができるようになる。そして、これは正極１ｂを集電部３ａの挟持部３ｃに接続固定する場合も同様である。
【００２５】
なお、上記実施形態では、長円筒形に巻回した発電要素１について説明したが、本発明はその他の巻回型の発電要素にも同様に実施可能である。ただし、例えば円筒形の発電要素の場合には、集電部２ａ，３ａの挟持部２ｃ，３ｃは、負極１ａや正極１ｂの巻きに沿って湾曲して形成する必要がある。
【００２６】
また、上記実施形態では、非水電解質二次電池について説明したが、本発明は、その他の電池一般に実施可能である。さらに、上記実施形態では、負極集電体２と正極集電体３に銅板とアルミニウム板を使う場合について説明したが、電池の種類に応じて他の金属板を用いることも可能である。
【００２７】
さらに、上記実施形態では、負極集電体２と正極集電体３の挟持部２ｃ，３ｃをかしめて超音波溶接する場合について説明したが、負極１ａや正極１ｂの端縁部を挟み込んで接続固定するものであれば、必ずしもこのような方法には限定されない。
【００２８】
【発明の効果】
以上の説明から明らかなように、本発明の電池によれば、集電体の集電部における複数の挟持部の間に平板状の平板部が形成されるので、この部分が発電要素の内部に突入して他方の電極に接触し短絡を起こすようなおそれがなくなる。また、このため、正負の電極を巻回する際のずれの量を少なくすることができるので、活物質を塗工する面積を広げて電池容量を増大させることもできるようになる。
【図面の簡単な説明】
【図１】本発明の一実施形態を示すものであって、発電要素に接続固定した負極集電体を示す斜視図である。
【図２】本発明の一実施形態を示すものであって、発電要素に接続固定する負極集電体と正極集電体の構成を示す斜視図である。
【図３】本発明の一実施形態を示すものであって、発電要素の上端に突出する負極の端縁部を振り分けるための治具を示す斜視図である。
【図４】本発明の一実施形態を示すものであって、集電部の挟持部に負極の端縁部が挟み込まれた状態を示す部分拡大図である。
【図５】非水電解質二次電池の発電要素の構成を示す斜視図である。
【図６】従来例を示すものであって、発電要素に接続固定する負極集電体の構成を示す斜視図である。
【図７】従来例を示すものであって、発電要素に接続固定した負極集電体を示す斜視図である。
【図８】従来例を示すものであって、発電要素に接続固定する負極集電体と正極集電体の構成を示す斜視図である。
【図９】従来例を示すものであって、集電部の挟持部に負極の端縁部が挟み込まれた状態を示す部分拡大図である。
【符号の説明】
１発電要素
１ａ負極
１ｂ正極
１ｃセパレータ
２負極集電体
２ａ集電部
２ｃ挟持部
２ｄ平板部
３正極集電体
３ａ集電部
３ｃ挟持部
３ｄ平板部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a battery including a wound power generation element in which strip-shaped positive and negative electrodes are wound via a strip-shaped separator.
[0002]
[Prior art]
FIG. 5 shows a configuration example of a nonaqueous electrolyte secondary battery including a long cylindrical wound power generation element 1. This power generation element 1 is configured by winding a strip-shaped negative electrode 1a and a positive electrode 1b in a long cylindrical shape via a strip-shaped separator 1c, and winding the negative electrode 1a and the positive electrode 1b with a slight shift up and down. Thus, only the upper edge of the negative electrode 1a protrudes from the upper end side of the power generation element 1, and only the lower edge of the positive electrode 1b protrudes from the lower end side. At this time, the negative electrode 1a does not apply the active material to the upper edge portion, and the positive electrode 1b does not apply the active material to the lower edge portion. Be sure to expose the metal foil. Further, the separator 1c is wound with such a width that the portion where the negative electrode 1a and the positive electrode 1b overlap is surely covered, but the upper and lower edge portions are not covered.
[0003]
In the non-aqueous electrolyte secondary battery, the negative electrode current collector 2 as shown in FIG. 6 is conventionally arranged at the upper end of the power generation element 1 to collect the negative electrode 1a. The negative electrode current collector 2 is made of a copper plate, and a current collecting part 2a is formed above the central one side of the upper end of the power generating element 1, and a flat terminal connection part 2b is drawn from the current collecting part 2a to generate power. The element 1 is disposed above one semicircular portion of the upper end portion. The current collecting portion 2a is formed by repeatedly bending a copper plate in a bellows shape to form a sandwiching portion 2c protruding upward and a pushing portion 2e protruding downward. The sandwiching part 2c is such that two vertical copper plates folded back at the top are arranged facing each other with a slight gap therebetween, and the pushing part 2e is two inclined copper plates folded at the bottom Is a portion where the interval is gradually widened to form a V-shaped cross section.
[0004]
As shown in FIG. 7, the negative electrode current collector 2 is formed by sandwiching a plurality of edge portions of the negative electrode 1a protruding from the upper end of the power generation element 1 into gaps between the holding portions 2c of the current collecting portion 2a. At the same time, the connection is fixed by ultrasonic welding. At this time, the current collector 2a pushes down the upper end of the power generating element 1 from above, thereby pushing the tip protruding downward of the pusher 2e between the upper edges of the negative electrode 1a. The upper edge portions of the negative electrodes 1a are distributed on the inclined surface and introduced into the gaps of the sandwiching portions 2c.
[0005]
Further, a positive electrode current collector 3 as shown in FIG. 8 is arranged at the lower end portion of the power generation element 1 to collect the positive electrode 1b. The positive electrode current collector 3 has a current collector 3a having the same structure as that of the negative electrode current collector 2, but an aluminum plate is used instead of the copper plate. The positive electrode current collector 3 is connected and fixed by caulking and ultrasonic welding by sandwiching the edge portion of the positive electrode 1b protruding from the lower end of the power generation element 1 into the gap of the clamping portion 3c of the current collecting portion 3a. . At this time, it is the same that the pushing portion 3e of the current collecting portion 3a distributes the end edge portion of the positive electrode 1b and introduces it into the gap of the holding portion 3c. However, here, an example in which the terminal connection portion 3b is pulled out to above the upper end portion of the power generation element 1 is shown. But when making the positive electrode terminal 5 protrude from the downward direction of the electric power generation element 1, this terminal connection part 3b is also arrange | positioned under the lower end part of the electric power generation element 1. FIG.
[0006]
For the sake of simplicity, the negative electrode 1a and the positive electrode 1b of the power generation element 1 are roughly wound with a small number of turns for the sake of simplicity. However, the current collector 2a is actually wound very densely with a large number of turns. , 3a, a plurality of edge portions of the negative electrode 1a and the positive electrode 1b are inserted and fixed in the gaps between the holding portions 2c and 3c. Further, the current collectors 2a and 3a of the negative electrode current collector 2 and the positive electrode current collector 3 are arranged not only on the central one side of the power generating element 1, but also above and below the both sides of the center to improve the current collection efficiency. In some cases.
[0007]
[Problems to be solved by the invention]
However, in the negative electrode 1a and the positive electrode 1b of the power generation element 1, since extremely thin metal foils such as copper and aluminum are exposed at the upper and lower end edges, the tips of the pushing portions 2e and 3e of the current collecting portions 2a and 3a are actually used. Is pushed between the edge portions of the negative electrode 1a and the positive electrode 1b and is caught on the inclined surfaces on both sides of the V-shaped cross section, and wrinkles or breaks. Therefore, the gap between the sandwiching portions 2c and 3c is smooth. There was a problem that could not be introduced.
[0008]
Further, when the pushing portions 2e and 3e are provided in the current collecting portions 2a and 3a as described above, the ends of the pushing portions 2e and 3e are plunged into the power generating element 1, so that no current is collected. There is a problem that a short circuit occurs due to contact with the positive electrode 1b or the negative electrode 1a, or the coating area of the active material becomes narrow and the battery capacity decreases. For example, as shown in FIG. 9, when the negative electrode 1a is connected and fixed to the sandwiching portion 2c of the current collector 2a, the upper end of the positive electrode 1b that is shifted downward approaches the tip of the push-in portion 2e, so that they are in contact with each other. This may cause a short circuit. In order to prevent this, if the amount of deviation between the negative electrode 1a and the positive electrode 1b is increased, the uncoated portion of the active material must be widened, so that the coating area is reduced by that amount and the battery capacity is reduced. Will do.
[0009]
In addition, about the problem that the edge part of the negative electrode 1a and the positive electrode 1b cannot be smoothly inserted in the clearance gap between the clamping parts 2c and 3c, the tip of the pushing parts 2e and 3e using a material having a small coefficient of friction and good sliding property is used. A comb-like jig having V-shaped teeth with a small angle is pushed into the upper end and lower end of the power generation element 1 so that the upper and lower end edges of the negative electrode 1a and the positive electrode 1b are clamped in advance 2c, 3c. If the current collectors 2a and 3a of the negative electrode current collector 2 and the positive electrode current collector 3 are inserted into positions corresponding to the gaps, the problem can be solved. However, even in this case, the problems that the tips of the push-in portions 2e and 3e are short-circuited and the coating area of the active material is not solved.
[0010]
The present invention has been made in order to cope with such a situation, and by providing a clamping portion directly on a flat metal plate, there is no possibility of short-circuiting with the electrode, and the coating area of the active material is increased. It aims at providing the battery which can do.
[0011]
[Means for Solving the Problems]
The battery according to claim 1 is formed by bending a single metal plate to form sandwiching portions at a plurality of locations, and a current collecting portion provided with a flat plate portion between these sandwiching portions, lifted from one end of the conductive portion to the upper end portion above the height of the clamping portion, comprising a current collector and a horizontal plate-like terminal connecting portion, the current collecting portion, of the upper and lower strip-shaped positive and negative electrodes, respectively winding with shifted in time axis direction is placed on the end on the power generating element of a wound-type wound through the strip-shaped separator, the edge portion of the positive or negative electrodes protruding end on the power generating element Is characterized in that it is sandwiched and clamped by the nearest clamping part of the current collecting part.
[0012]
According to the first aspect of the present invention, since the plurality of sandwiching portions for connecting and fixing the edge portions of the electrodes are connected via the flat plate portion, this portion does not enter into the power generating element. For this reason, there is no possibility that the electrode on the side that is not connected and fixed to the clamping part contacts the current collecting part to cause a short circuit. For this reason, since the amount of deviation when winding the positive and negative electrodes can be reduced, the area on which the active material is applied can be expanded to increase the battery capacity.
[0013]
The battery according to claim 2 is characterized in that the edge portion of the electrode is clamped by being sandwiched by the sandwiching portion of the current collector, and is connected and fixed to the sandwiching portion by ultrasonic welding.
[0014]
According to the second aspect of the present invention, the edge portion of the electrode can be securely connected and fixed to the clamping portion of the current collecting portion by caulking and ultrasonic welding.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0016]
1 to 4 show an embodiment of the present invention. FIG. 1 is a perspective view showing a negative electrode current collector connected and fixed to a power generation element. FIG. 2 is a negative electrode current collector connected and fixed to the power generation element. 3 is a perspective view showing the configuration of the positive electrode current collector, FIG. 3 is a perspective view showing a jig for distributing the end edge of the negative electrode protruding from the upper end of the power generation element, and FIG. It is the elements on larger scale which show the state where the edge part was inserted | pinched. In addition, the same number is attached | subjected to the structural member which has the function similar to the prior art example shown in FIGS.
[0017]
This embodiment demonstrates the nonaqueous electrolyte secondary battery provided with the electric power generation element 1 wound by the long cylindrical shape used for an electric vehicle etc. As shown in FIG. 5, the power generating element 1 of the nonaqueous electrolyte secondary battery is wound by shifting the negative electrode 1a and the positive electrode 1b slightly in the vertical direction (winding axis direction). 1, only the upper edge of the negative electrode 1a protrudes from the upper end side, and only the lower edge of the positive electrode 1b protrudes from the lower end side. The negative electrode 1a is obtained by applying a negative electrode active material such as graphite on the surface of a strip-like copper foil, and the positive electrode 1b is obtained by applying a positive electrode active material such as lithium cobalt composite oxide on the surface of a strip-like aluminum foil. is there. However, the negative electrode 1a applies a negative electrode active material only to a portion except the upper edge portion, and the positive electrode 1b applies a positive electrode active material only to a portion other than the lower edge portion, thereby generating power. Copper foil and aluminum foil are exposed at the upper and lower ends of element 1 so as to protrude. The separator 1c uses a belt-like microporous resin film and is wound with such a width that the portions where the negative electrode 1a and the positive electrode 1b overlap with each other are reliably covered, but the upper and lower end edges are not covered.
[0018]
A negative electrode current collector 2 and a positive electrode current collector 3 as shown in FIG. 2 are connected to the power generation element 1. The negative electrode current collector 2 is obtained by pressing a copper plate, and the current collector 2 a is disposed above the central one side of the upper end of the power generation element 1. The current collector 2a is formed by bending the copper plate of the negative electrode current collector 2 to form sandwiching portions 2c at three locations and providing flat plate portions 2d between these sandwiching portions 2c. . The sandwiching portion 2c is a portion in which two copper plates are erected facing each other by bending a horizontal flat copper plate upward and folding back at the top. A gap opening downward is provided between the two copper plates erected so as to face each other. The flat plate portion 2d is a horizontal flat plate-like portion that connects adjacent ones of the sandwiching portions 2c at the lower end portions, and is provided so as to open a certain distance between the respective sandwiching portions 2c.
[0019]
One end of the current collector 2a in the negative electrode current collector 2 is lifted to a height equal to or higher than the upper end of the sandwiching part 2c, and is drawn out above one semicircular part of the upper end of the power generating element 1 to be a horizontal flat plate. Is connected to the terminal connection portion 2b. The lower end portion of the negative electrode terminal 4 is connected and fixed to the terminal connection portion 2b by caulking. Further, the positive electrode current collector 3 is obtained by press-working an aluminum plate, and has a configuration similar to that of the negative electrode current collector 2 and is formed with a current collector 3a that is upside down. And one end of this current collection part 3a is pulled out to the upper direction of the other semicircle part of an upper end part along the side surface of the electric power generation element 1, and is connected to the horizontal flat terminal connection part 3b. The lower end portion of the positive electrode terminal 5 is connected and fixed to the terminal connection portion 3b by caulking.
[0020]
As shown in FIG. 3, the power generating element 1 is inserted at the upper end of the power generating element 1 by inserting a comb-like jig 6 formed with downward V-shaped teeth into the central one side of the upper end. The protruding edge of the negative electrode 1a is distributed and collected in three places. The jig 6 is made of a material having high hardness such as high-density polyethylene, and by reducing the angle of the tip of the tooth and lengthening the V shape, the thin copper foil exposed at the edge of the negative electrode 1a is formed. These can be distributed smoothly without causing wrinkles or breaking.
[0021]
Next, as shown in FIG. 1, the negative electrode current collector 2 is placed on the upper end portion of the power generation element 1, and the edge portions of the plurality of negative electrodes 1 a distributed by the jig 6 are connected to the current collector portion 2 a. Are sandwiched in the gaps between the respective sandwiching portions 2c. When the edge portion of the negative electrode 1a is sandwiched between the sandwiching portions 2c, the jig 6 is removed. Then, by crimping the two copper plates of each sandwiching portion 2c and performing ultrasonic welding, a portion where the copper foil at the edge of the negative electrode 1a sandwiched between these sandwiching portions 2c is exposed is collected in the current collecting portion 2a. Secure the connection. The caulking work is performed by inserting caulking tool attachments on both sides of each clamping part 2c from above and applying a force to crush the two copper plates. Further, ultrasonic welding is performed by inserting ultrasonic welder attachments on both sides of each sandwiching portion 2c from above and applying ultrasonic vibration to the two copper plates. The flat plate portion 2d is provided so as to have a certain gap as described above in order to provide a space for inserting these attachments between the adjacent sandwiching portions 2c. For the sake of simplicity, the negative electrode 1a and the positive electrode 1b of the power generation element 1 are roughly wound with a small number of turns for the sake of simplicity. However, the current collector 2a is actually wound very densely with a large number of turns. A plurality of edge portions of the negative electrode 1a are sandwiched in the gaps of the respective sandwiching portions 2c, and are fixedly connected.
[0022]
Similarly to the negative electrode current collector 2, the positive electrode current collector 3 also has a portion where the aluminum foil at the edge of the positive electrode 1 b protruding from the lower end of the power generation element 1 is exposed as a gap between the holding portions 3 c of the current collector 3 a. A plurality of sheets are clamped together and connected and fixed by ultrasonic welding. Note that the terminal connection portion 3b of the positive electrode current collector 3 drawn out from the current collection portion 3a to the upper end portion is disposed above the current collection portion 2a of the negative electrode current collector 2, An insulating material is inserted between them to prevent a short circuit.
[0023]
The power generation element 1 in which the negative electrode current collector 2 and the positive electrode current collector 3 are connected and fixed is housed in a long cylindrical battery case (not shown), and a nonaqueous electrolyte solution is injected and sealed, so that the nonaqueous electrolyte secondary is obtained. It becomes a battery. Moreover, the negative electrode terminal 4 and the positive electrode terminal 5 are each insulatedly sealed and protruded from the upper part of the battery.
[0024]
According to the above configuration, the plurality of sandwiching portions 2c and 3c for connecting and fixing the edge portions of the negative electrode 1a and the positive electrode 1b are connected via the flat plate portions 2d and 3d, respectively, and the flat plate portions 2d and 3d are connected to the power generation element. Since it does not rush into the interior of the battery 1, there is no risk of a short circuit and the battery capacity can be increased. For example, as shown in FIG. 4, when the negative electrode 1a is connected and fixed to the sandwiching portion 2c of the current collector 2a, there is a gap between the upper end of the positive electrode 1b that is shifted downward and the back surface of the flat plate portion 2d. Since a sufficient distance is maintained, there is no possibility that they will contact and cause a short circuit. In addition, if the upper end of the positive electrode 1b and the back surface of the flat plate portion 2d are sufficiently separated in this way, there is no risk of a short circuit even if the amount of deviation between the negative electrode 1a and the positive electrode 1b is reduced. By narrowing the uncoated portion of the active material, the coating area can be increased by that amount, and the battery capacity can be increased. This also applies to the case where the positive electrode 1b is connected and fixed to the clamping portion 3c of the current collector 3a.
[0025]
In addition, in the said embodiment, although the electric power generation element 1 wound by the long cylindrical shape was demonstrated, this invention can be implemented similarly to another winding type electric power generation element. However, for example, in the case of a cylindrical power generation element, the sandwiching portions 2c and 3c of the current collecting portions 2a and 3a need to be curved along the winding of the negative electrode 1a and the positive electrode 1b.
[0026]
Moreover, although the said embodiment demonstrated the nonaqueous electrolyte secondary battery, this invention can be implemented in another battery generally. Furthermore, although the said embodiment demonstrated the case where a copper plate and an aluminum plate were used for the negative electrode collector 2 and the positive electrode collector 3, other metal plates can also be used according to the kind of battery.
[0027]
Furthermore, in the above-described embodiment, the case where the sandwiching portions 2c and 3c of the negative electrode current collector 2 and the positive electrode current collector 3 are crimped and ultrasonic welding is described, but the edge portions of the negative electrode 1a and the positive electrode 1b are sandwiched and connected. If fixed, it is not necessarily limited to such a method.
[0028]
【The invention's effect】
As is clear from the above description, according to the battery of the present invention, the flat plate portion is formed between the plurality of sandwiching portions in the current collector portion of the current collector, and this portion is the interior of the power generation element. There is no risk of rushing into contact with the other electrode and causing a short circuit. For this reason, since the amount of deviation when winding the positive and negative electrodes can be reduced, it is possible to increase the battery capacity by expanding the area where the active material is applied.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a negative electrode current collector connected to a power generation element according to an embodiment of the present invention.
FIG. 2 is a perspective view illustrating a configuration of a negative electrode current collector and a positive electrode current collector that are connected and fixed to a power generation element according to an embodiment of the present invention.
FIG. 3 is a perspective view showing a jig for distributing an end edge portion of a negative electrode protruding from an upper end of a power generation element according to an embodiment of the present invention.
FIG. 4 is a partially enlarged view showing an embodiment of the present invention and showing a state in which an end edge of a negative electrode is sandwiched between clamping parts of a current collector.
FIG. 5 is a perspective view showing a configuration of a power generation element of a nonaqueous electrolyte secondary battery.
FIG. 6 is a perspective view illustrating a configuration of a negative electrode current collector that is connected and fixed to a power generation element according to a conventional example.
FIG. 7 is a perspective view showing a negative electrode current collector connected and fixed to a power generation element, showing a conventional example.
FIG. 8 is a perspective view illustrating a configuration of a negative electrode current collector and a positive electrode current collector that are connected and fixed to a power generation element according to a conventional example.
FIG. 9 is a partial enlarged view showing a conventional example and showing a state in which an end edge portion of a negative electrode is sandwiched between clamping portions of a current collecting unit.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Power generation element 1a Negative electrode 1b Positive electrode 1c Separator 2 Negative electrode collector 2a Current collector 2c Holding part 2d Flat plate part 3 Positive electrode collector 3a Current collecting part 3c Holding part 3d Flat plate part

Claims

By bending a single metal plate, a clamping part is formed at a plurality of locations, and a current collecting part in which a flat plate part is provided between these clamping parts, and a clamping part from one end of the current collecting part A current collector having a horizontal plate-like terminal connection portion that is lifted to a height equal to or higher than the upper end of the current collector , and the current collector portion is formed in a belt shape by shifting the belt-like positive and negative electrodes in the upper and lower winding axis directions, respectively. along with being placed on the end on the power generating element of a wound type obtained by winding a separator, a positive or negative electrode protruding end on the power generating element edge portion of the collector portion nearest A battery characterized in that it is sandwiched and fixedly connected by a clamping part.

2. The battery according to claim 1, wherein an edge portion of the electrode is clamped by being sandwiched by a sandwiching portion of a current collector, and is connected and fixed to the sandwiching portion by ultrasonic welding.