JP2004039577A

JP2004039577A - Thin battery, battery pack, compound battery pack, and vehicle

Info

Publication number: JP2004039577A
Application number: JP2002198109A
Authority: JP
Inventors: Kyoichi Watanabe; 渡邉　恭一
Original assignee: Nissan Motor Co Ltd
Current assignee: Nissan Motor Co Ltd
Priority date: 2002-07-08
Filing date: 2002-07-08
Publication date: 2004-02-05
Anticipated expiration: 2022-07-08
Also published as: JP3719235B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flat battery having a structure strong against an imposed external force. <P>SOLUTION: The flat battery having a terminal led out from an end edge of an outer periphery is constituted of two sheets of positive electrode plates 101 coated with a positive electrode active material, five separators 102 of micro-porous films, two sheets of negative electrode plates 103 coated with a negative electrode active material, positive electrode terminals 104 connected to each positive electrode plate 101, negative electrode terminals 105 connected to each negative electrode plate, an electrolyte not illustrated, and an upper part cell outer packaging member 106 and a lower part cell outer packaging member 107 to seal these above. The cell outer packaging members 106, 107 are constituted of a first resin layer located in the innermost layer, a second resin layer located in the outermost layer, and a metal layer pinched by those two layers and laminated, the first resin layer having a smaller Young's modulus than the second resin layer. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【技術分野】
本発明は、封止手段の外周部の端縁から導出する端子を有する薄型電池に関し、特に印加される振動に対して強い構造を有する薄型電池に関する。
【０００２】
【背景技術】
封止手段の外周部の端縁から導出する端子を有する薄型電池の使用態様や使用条件の多様化に伴って、当該薄型電池に対して外部から印加される振動が増加する。この振動により、正極端子又は負極端子が電池外装部材から導出する部分（以下、単に端子導出部ともいう。）の剥離等により薄型電池内部に注入された電解液が漏洩し、当該薄型電池の性能低下を招く場合がある。
【０００３】
【発明の開示】
本発明は、印加される外力に対して強い構造を有する薄型電池を提供することを目的とする。
【０００４】
上記目的を達成するために、本発明によれば、２層の合成樹脂層に挟まれた１層の金属層を少なくとも有する封止手段を備え、正極端子及び負極端子が前記封止手段の外周部の端縁から導出する薄型電池であって、前記封止手段の最内層に位置する第１の合成樹脂層が、前記封止手段の最外層に位置する第２の合成樹脂層のヤング率より小さいヤング率を有する薄型電池が提供される（請求項１参照）。
【０００５】
本発明では、電池外装部材が有する最内層の第１の合成樹脂層のヤング率を最外層の第２の合成樹脂層のヤング率より小さくなるように操作することにより、当該端子導出部の共振周波数を加振振動数から離遠させるように移行させ、共振を防止する。これにより、外部から印加される振動による端子導出部の剥離等の発生を著しく減少することが出来、印加される振動に対して強い構造を有する薄型電池とすることが可能となる。
【０００６】
【発明の実施の形態】
以下、本発明の実施形態を図面に基づいて説明する。
第１実施形態
図１（Ａ）は本発明の第１実施形態に係る薄型電池の全体を示す平面図、図１（Ｂ）は（Ａ）のＩＩ−ＩＩ線に沿う断面図である。図２は図１（Ａ）のＩＩＩ部の拡大断面図である。図３は図２のマス−バネ系モデルである。図４は本発明の第１実施形態に係る端子導出部での振動伝達率スペクトルを示すグラフである。図１は一つの薄型電池（単位電池）を示し、この薄型電池１０を複数積層することにより所望の電圧、容量の組電池が構成される。
【０００７】
まず図１を参照しながら、本発明の第１実施形態に係る薄型電池１０の全体構成について説明すると、本例の薄型電池１０はリチウム系の薄型二次電池であり、２枚の正極板１０１と、５枚のセパレータ１０２と、２枚の負極板１０３と、正極端子１０４と、負極端子１０５と、上部電池外装部材１０６と、下部電池外装部材１０７と、特に図示しない電解質とから構成されている。このうちの正極板１０１，セパレータ１０２，負極板１０３および電解質を特に発電要素１０９と称する。
【０００８】
なお、正極板１０１，セパレータ１０２，負極板１０３の枚数には何ら限定されず、１枚の正極板１０１，３枚のセパレータ１０２，１枚の負極板１０４でも発電要素１０９を構成することができる。必要に応じて正極板、負極板およびセパレータの枚数を選択して構成することができる。
【０００９】
発電要素１０９を構成する正極板１０１は、金属酸化物などの正極活物質に、カーボンブラックなどの導電材と、ポリ四フッ化エンチレンの水性ディスパージョンなどの接着剤とを、重量比でたとえば１００：３：１０の割合で混合したものを、正極側集電体としてのアルミニウム箔などの金属箔の両面に塗着、乾燥させ、圧延したのち所定の大きさに切断したものである。なお、上記のポリ四フッ化エチレンの水性ディスパージョンの混合比率は、その固形分である。
【００１０】
正極活物質としては、例えばニッケル酸リチウム（ＬｉＮｉＯ_２）、マンガン酸リチウム（ＬｉＭｎＯ_２）、コバルト酸リチウム（ＬｉＣｏＯ_２）などのリチウム複合酸化物や、カルコゲン（Ｓ、Ｓｅ、Ｔｅ）化物を挙げることができる。これらの材質は薄型電池内部の発熱を比較的拡散し易く、端子への伝熱による端子の膨張による伸びを少なく出来、端子から後述する電池外装部材へ伝達する引張り応力を極力抑制することが可能となる。
【００１１】
発電要素１０９を構成する負極板１０３は、例えば非晶質炭素、難黒鉛化炭素、易黒鉛化炭素、または黒鉛などのように、正極活物質のリチウムイオンを吸蔵および放出する負極活物質に、有機物焼成体の前駆体材料としてのスチレンブタジエンゴム樹脂粉末の水性ディスパージョンをたとえば固形分比１００：５で混合し、乾燥させたのち粉砕することで、炭素粒子表面に炭化したスチレンブタジエンゴムを担持させたものを主材料とし、これに、アクリル樹脂エマルジョンなどの結着剤をたとえば重量比１００：５で混合し、この混合物を、負極側集電体としてのニッケル箔或いは銅箔などの金属箔の両面に塗着、乾燥させ、圧延したのち所定の大きさに切断したものである。
【００１２】
特に負極活物質として非晶質炭素や難黒鉛化炭素を用いると、充放電時における電位の平坦特性に乏しく放電量にともなって出力電圧も低下するので、通信機器や事務機器の電源には不向きであるが、電気自動車等の電源として用いると急激な出力低下がないので有利である。
【００１３】
また、発電要素１０９のセパレータ１０２は、上述した正極板１０１と負極板１０３との短絡を防止するもので、電解質を保持する機能を備えてもよい。セパレータ１０２は、例えばポリエチレン（ＰＥ）やポリプロピレン（ＰＰ）などのポリオレフィン等から構成される微多孔性膜であり、過電流が流れると、その発熱によって層の空孔が閉塞され電流を遮断する機能をも有する。
【００１４】
なお、本発明のセパレータ１０２は、ポリオレフィンなどの単層膜にのみ限られず、ポリプロピレン膜をポリエチレン膜でサンドイッチした三層構造や、ポリオレフィン微多孔膜と有機不織布などを積層したものも用いることができる。セパレータ１０２を複層化することで、過電流の防止機能、電解質保持機能およびセパレータの形状維持（剛性向上）機能などの諸機能を付与することができる。また、セパレータ１０２の代わりにゲル電解質又は真性ポリマー電解質等を用いることもできる。
【００１５】
以上の発電要素１０９は、上から正極板１０１と負極板１０３とが交互に、且つ当該正極板１０１と負極板１０３との間にセパレータ１０２が位置するような順序で積層され、さらに、その最上部及び最下部にセパレータ１０２が一枚ずつ積層されている。そして、２枚の正極板１０１のそれぞれは、正極側集電部１０４ａを介して、金属箔製の正極端子１０４に接続される一方で、２枚の負極板１０３は、負極側集電部１０５ａを介して、同じく金属箔製の負極端子１０５に接続されている。なお、正極端子１０４も負極端子１０５も電気化学的に安定した金属材料であれば特に限定されないが、正極端子１０４としてはアルミニウムやアルミニウム合金、銅又はニッケルなどを挙げることができ、負極端子１０５としてはニッケル、銅、ステンレス又は鉄などを挙げることができる。これらの金属は、金属の抵抗値、線膨張係数、抵抗率において薄型電池の構成要素として特に適当であり、使用温度を変えた場合にも、端子から後述する電池外装部材へ伝達する引張り応力を極力抑制することが可能となる。また、本例の正極側集電部１０４ａも負極側集電部１０５ａの何れも、正極板１０４および負極板１０５の集電体を構成するアルミニウム箔やニッケル箔、銅箔、鉄箔を延長して構成されているが、別途の材料や部品により当該集電部１０４ａ，１０５ａを構成することもできる。
【００１６】
発電要素１０９は、上部電池外装部材１０６及び下部電池外装部材１０７（封止手段）により封止されている。本発明の第１実施形態における上部電池外装部材１０６は、図２に示すように、薄型電池１０の内側から外側に向かって、第１の樹脂層１０６ａ、金属層１０６ｂ、第２の樹脂層１０６ｃの順で３つの層１０６ａ〜１０６ｃが積層される。この３つの層１０６ａ〜１０６ｃは、上部電池外装部材１０６の全面に渡って積層されており、第１の樹脂層１０６ａは、例えばポリエチレン、変性ポリエチレン、ポリプロピレン、変性ポリプロピレン、アイオノマーなどの耐電解液性及び熱融着性に優れた樹脂フィルムである。第２の樹脂層１０６ｃは、例えば、ポリアミド系樹脂、ポリエステル系樹脂等の電気絶縁性に優れた樹脂フィルムである。このように、電池外装部材の第１の樹脂層を、ポリプロピレン、変性ポリプロピレン、ポリエチレン、変性ポリエチレン、アイオノマーなどの樹脂で構成することにより、金属からなる正極端子又は負極端子と電池外装部材の第１の樹脂層との良好な融着性を確保することが可能となる。金属層１０６ｂは、例えば、アルミニウムなどの金属箔である。従って、上部電池外装部材１０６は、例えば、アルミニウムなどの金属箔の一方の面（薄型電池の内側面）をポリエチレン、変性ポリエチレン、ポリプロピレン、変性ポリプロピレン、アイオノマーなどの樹脂でラミネートし、他方の面（薄型電池の外側面）をポリアミド系樹脂、ポリエステル系樹脂等でラミネートした、樹脂−金属薄膜ラミネート材などの可撓性を有する材料で形成される。このように、電池外装部材が樹脂層に加えて金属層を具備することにより、電池外装部材の強度を向上させることが可能となる。なお、第２の樹脂層１０６ｃは、金属層１０６ｂの膜厚及び第１の樹脂層１０６ａの膜厚より相対的に薄い膜厚を有しており、第１の樹脂層１０６ａと金属層１０６ｂとによる後述する動吸振器的特性を効果的に作用させることが可能となる。
【００１７】
下部電池外装部材１０７は、上部電池外装部材１０６と同様の構造のものが用いられ、図２に示すように、薄型電池１０の内側から外側に向かって、第１の樹脂層１０７ａ、金属層１０７ｂ、第２の樹脂層１０７ｃの順で、３つの層１０７ａ〜１０７ｃが積層される。下部電池外装部材１０７の第１の樹脂層１０７ａは、上部電池外装部材１０６の第１の樹脂層１０６ａと同様に、例えばポリエチレン、変性ポリエチレン、ポリプロピレン、変性ポリプロピレン、アイオノマーなどの耐電解液性及び熱融着性に優れた樹脂フィルムである。下部電池外装部材１０７の金属層１０７ｂは、上部電池外装部材１０６の金属層１０６ｂと同様に、例えば、アルミニウムなどの金属箔である。下部電池外装部材１０７の第２の樹脂層１０７ｃは、上部電池外装部材１０６の第２の樹脂層１０６ｃと同様に、例えばポリアミド系樹脂、ポリエステル系樹脂等の電気絶縁性に優れた樹脂フィルムである。第２の樹脂層１０７ｃは、金属層１０７ｂの膜厚及び第１の樹脂層１０７ａの膜厚より相対的に薄い膜厚を有しており、第１の樹脂層１０７ａと金属層１０７ｂとによる後述する動吸振器的特性を効果的に作用させることが出来る。
【００１８】
さらに、これら正極端子１０４又は負極端子１０５と、電池外装部材１０６、１０７とから構成される端子導出部１１１は、当該端子導出部１１１の共振周波数を加振振動数から離遠させるように移行させ、当該端子導出部１１１における共振を防止するために、図３に示すような２自由度のマス−バネ系を構成している。図３のマス−バネ系モデルにおいて、薄型電池１０の正極端子１０４又は負極端子１０５が質量ｍ_１の第１のマス部Ｍに相当し、電池外装部材１０６、１０７の金属層１０６ｂ、１０７ｂが質量ｍ_２の第２のマス部Ｍａ、Ｍｂに相当する。また、上部電池外装部材１０６の第１の樹脂層１０６ａ及び下部電池外装部材１０７の第１の樹脂層１０７ａがヤング率ｋ_１の第１のバネ部Ｋ及び減衰要素Ｃに相当し、電池外装部材１０６、１０７の第２の樹脂層１０６ｃ、１０７ｃがヤング率ｋ_２の第２のバネ部Ｋａ、Ｋｂに相当し、第１のバネ部Ｋのヤング率ｋ_１は、第２のバネ部Ｋａ、Ｋｂのヤング率ｋ_２に対して５〜５５％の関係にある。このように、第２のバネ部Ｋａ、Ｋｂを第１のバネ部Ｋのヤング率ｋ_２より小さなヤング率ｋ_１とすることにより、第１のバネ部Ｋである第１の樹脂層１０６ａ、１０７ａと第２のマス部Ｍａ、Ｍｂである金属層１０６ｂ、１０７ｂとが動吸振器的に効果的に作用して、端子導出部１１１のマス−バネ系の共振周波数を加振振動数から離縁させるように移行させることが可能となる。なお、第１のバネ部Ｋのヤング率ｋ_１を第２のバネ部Ｋａ、Ｋｂのヤング率ｋ_２に対して５％未満にすると、第１のバネ部Ｋと第２のバネ部Ｋａ、Ｋｂとの動的バネ定数の差が過剰となり、端子導出部１１１の構造が弱くなる可能性がある。また、第１のバネ部Ｋのヤング率ｋ_１を第２のバネ部Ｋａ、Ｋｂのヤング率ｋ_２に対して５５％より大きくすると、ヤング率に依存する動的バネ定数の差が小さく、第２のマス部Ｍａ、Ｍｂ及び第１のバネ部Ｋによる動吸振器的な作用が弱まり、端子導出部１１１の共振周波数の移行が困難となる。
【００１９】
また、上述の正極端子１０４及び負極端子１０５は、電池外装部材１０６、１０７の金属層１０６ｂ、１０７ｂの膜厚の２〜５倍の厚さを有する。ここで、正極端子１０４及び負極端子１０５の厚さを金属層１０６ｂ、１０７ｂの膜厚の２倍未満とすると、当該金属層１０６ｂ、１０７ｂが端子導出部１１１の共振周波数に与える影響が大きくなり、当該端子導出部１１１の共振周波数の移行が困難となる可能性がある。また、正極端子１０４及び負極端子１０５の厚さを金属層１０６ｂ、１０７ｂの膜厚の５倍より大きくすると、金属層１０６ｂ、１０７ｂが端子導出部１１１の共振周波数に与える影響が小さくなり、必要とする振動数への移行が困難になる。
【００２０】
上述の２自由度のマス−バネ系における共振周波数（固有振動数）ω_１、ω_２は式１から実質的に算出することが可能である。
【００２１】
【式１】

本発明の第１実施形態に係る薄型電池の端子導出部は、完全な２自由度型マス−バネ系ではないため、上式により完全に説明することは出来ないが、上式を参考にして端子導出部における共振周波数のチューニングが可能である。なお、各層及び端子の材質の変更により、上式の質量、ヤング率を変化させて、端子導出部の共振周波数をチューニングしても良い。
【００２２】
電池外装部材を構成する各層の材質、膜厚、ヤング率と、正極端子及び負極端子の材質、厚さとを操作することにより、端子導出部のマス−バネ系における一次固有振動数、二次固有振動数を任意に設定することが可能となり、当該端子導出部の共振周波数を加振振動数から離遠させるように移行させ、共振を抑制することが可能となる。
【００２３】
図４は、第１実施形態に係る薄型電池の端子導出部における縦軸に加振振幅と応答振幅との比である振動伝達率、横軸に周波数の振動伝達率スペクトルを示す。同図に示すように、例えば、主たる加振振動数が約１００Ｈｚ以下に特に集中する車両等での薄型電池の使用する場合において、本発明の第１実施形態に係るチューニングにより、端子導出部の共振周波数を約１００Ｈｚ以上に移行させて加振振動数から離遠させることにより、加振に対する共振を防止して薄型電池を有効に活用することが可能となる。なお、加振振動数は約１００Ｈｚ以下に特に限定されず、それ以上の加振振動数に対しても、上記のチューニングを行うことが可能である。
【００２４】
さらに、図１に示すように、封止された電池外装１０６、１０７の一方の端部から、正極端子１０４が導出するが、正極端子１０４の厚さ分だけ上部電池外装１０６と下部電池外装１０７との接合部に隙間が生じるので、薄型電池１０内の封止性を維持するために、当該正極端子１０４と電池外装１０６、１０７とが接触する部分に、ポリエチレンやポリプロピレン等から構成されたシールフィルムを熱融着などの方法により介在させることもできる。
【００２５】
同様に、封止された電池外装１０６、１０７の他方の端部からは、負極端子１０５が導出するが、ここにも正極端子１０４側と同様に、当該負極端子１０５と電池外装１０６、１０７とが接触する部分にシールフィルムを介在させることもできる。なお、正極端子１０４および負極端子１０５の何れにおいても、シールフィルムは電池外装１０６，１０７を構成する樹脂と同系統の樹脂から構成することが熱融着性の点から望ましい。
【００２６】
これらの電池外装部材１０６、１０７によって、上述した発電要素１０９、正極側集電部１０４ａ、正極端子１０４の一部、負極側集電部１０５ａおよび負極端子１０５の一部を包み込み、当該電池外装部材１０６、１０７により形成される空間に、有機液体溶媒に過塩素酸リチウム、ホウフッ化リチウム等のリチウム塩を溶質とした液体電解質を注入したのち、上部電池外装部材１０６及び下部電池外装部材１０７の外周縁の熱融着領域１１０を熱プレスにより熱融着し、封止する。
【００２７】
このように封止された薄型電池１０は、総厚１〜１０［ｍｍ］を有することが好ましい。薄型電池の厚さを１０［ｍｍ］以下とすることにより、当該薄型電池内部に熱がこもりにくくなり、電池外装部材の界面に応力を伝達する可能性が低くなると共に、電池の熱劣化の影響も減少する。また、薄型電池の厚さを１［ｍｍ］以上とすることにより、十分な容量を確保することが出来、経済的な効率を高くすることが可能となる。
【００２８】
有機液体溶媒として、プロピレンカーボネート（ＰＣ）、エチレンカーボネート（ＥＣ）、ジメチルカーボネート（ＤＭＣ）などのエステル系溶媒を挙げることができるが、本発明の有機液体溶媒はこれにのみ限定されることなく、エステル系溶媒に、γ−ブチラクトン（γ−ＢＬ）、ジエトシキエタン（ＤＥＥ）等のエーテル系溶媒その他を混合、調合した有機液体溶媒も用いることができる。
【００２９】
以下に、上述の薄型電池を複数組み合わせることにより構成される組電池、及び当該組電池を複数組み合わせることにより構成される複合組電池について説明する。
【００３０】
図５は本発明の第１実施形態に係る複数の薄型電池の接続方法を示す図であり、図５（Ａ）は並列接続を示し、図５（Ｂ）は比較のための直列接続を示す。図６は本発明の第１実施形態に係る複数の薄型電池の他の接続方法を示す図であり、図６（Ａ）は並列接続を示し、図６（Ｂ）は比較のための直列接続を示す。図７は本発明の第１実施形態に係る複数の薄型電池により構成される組電池の斜視図、図８（Ａ）は図７の組電池の平面図、図８（Ｂ）は図７の組電池の正面図、図８（Ｃ）は図７の組電池の側面図、図９は図７の組電池より構成される複合組電池の斜視図、図１０（Ａ）は図９の複合組電池の平面図、図１０（Ｂ）は図９の複合組電池の正面図、図１０（Ｃ）は図９の複合組電池の側面図、図１１は本発明の第１実施形態に係る複合組電池を車両に搭載した模式図を示す。
【００３１】
上述の薄型電池１０を電気的に接続して複数の薄型電池１０を有する組電池２０を構成する場合、特に図５（Ａ）及び図６（Ａ）に示す配置による２つの接続構造が、印可される外力に対してさらに強い構造を付加する。
【００３２】
一つ目の接続構造は、図５（Ａ）に示すように、第１の薄型電池１０ａの正極端子１０４と、第２の薄型電池１０ｂの正極端子１０４とが同一方向に導出するような方向で、第１の薄型電池１０ａと第２の薄型電池１０ｂを実質的に同一平面上に並置させる。そして、第１の薄型電池１０ａの正極端子１０４と、第２の薄型電池１０ｂの正極端子１０４とを、第１のバスバー２１ａにより電気的に接続する。また、第１の薄型電池１０ａの負極端子１０５と第２の薄型電池１０ｂの負極端子１０５とを、第２のバスバー２１ｂにより電気的に接続する。
【００３３】
二つ目の接続構造は、図６（Ａ）に示すように、第１の薄型電池１０ａの正極端子１０４と、第２の薄型電池１０ｂの正極端子１０４とが同一方向に導出するような方向で、第１の薄型電池１０ａの鉛直上向きの面と第２の薄型電池１０ｂの鉛直下向きの面とを接触させて、第１の薄型電池１０ａと第２の薄型電池１０ｂとを積層する。そして、第１の薄型電池１０ａの正極端子１０４と第２の薄型電池１０ｂの正極端子１０４とを溶着して電気的に接続し、同様に、第１の薄型電池１０ａの負極端子１０５と第２の薄型電池１０ｂの負極端子１０５とを溶着して電気的に接続する。
【００３４】
図５（Ｂ）及び図６（Ｂ）に示すような直列に接続された場合、印加される外力によって、各薄型電池１０ａ、１０ｂの正極端子１０４には逆位相の捻れ（図５（Ｂ）及び図６（Ｂ）において捻れの方向を矢印により示す。）が生じるが、これに対し上記に説明した接続構造は、薄型電池１０ａ、１０ｂの正極端子１０４同士及び負極端子１０５同士が接続されているため、各薄型電池１０ａ、１０ｂに生じる応力が同位相となり、当該端子１０４、１０５に生じる捻れを極力抑えることが出来、端子と電池外装部材との間の界面に剥離が生じる可能性が低くなる。また、正極端子の金属と負極端子の金属とが異なる場合には、それに伴って、端子導出部に生ずる引張り応力も異なり界面剥離の原因になりうるが、上述の並列接続により薄型電池の端子導出部に生じる引張り応力を実質的に同等のものとすることが可能となる。
【００３５】
図７及び図８（Ａ）〜（Ｃ）は、例えば上述の２通りの接続構造を用いて並列接続された２４個の薄型電池１０から構成させる組電池２０を示す。組電池２０は、２４個の薄型電池１０と、組電池用端子２２、２３と、組電池用カバー２５とから構成されている。特に図示しないが、各薄型電池１０の各同極端子間は上述の接続構造でバスバー２１ａ、２１ｂにより並列接続されており、各正極端子１０４を接続する第１のバスバー２１ａは、組電池用カバー２５から導出する略円柱形状の組電池用正極端子２２に接続されている。同様に、各負極端子１０５を接続する第２のバスバー２１ｂは、組電池用カバー２５から導出する略円柱形状の組電池用負極端子２３に接続されている。これらの接続が完了し、２４個の薄型電池１０が組電池用カバー２５に挿入されると、当該組電池用カバー２５と当該組電池２０の他の構成要素との間に形成される空間に充填剤２４が充填され、封止される。さらに、後述する複合組電池として薄型電池が積層された際に、薄型電池同士の振動を極力低減するために、組電池用カバー２５の下面四隅に外部弾性体２６が取り付けられる。
【００３６】
図９及び図１０（Ａ）〜（Ｃ）は、図７に示す組電池２０を電気的に接続した６個の組電池２０から構成される複合組電池３０を示す。図９及び図１０（Ａ）〜（Ｃ）に示すように、複合組電池３０は、組電池２０の端子２２、２３がそれぞれ同一方向に向くように積層されている。すなわち、ｍ段目に位置する組電池２０の端子２２、２３と、ｍ＋１段目に位置する組電池２０の端子２２、２３とが同一方向に向くように、ｍ段目の組電池２０の上にｍ＋１段目の組電池２０が積層される（ｍ：自然数）。そして、同一方向を向いた全ての組電池２０の組電池用正極端子２２を、当該複合組電池３０と外部とを接続する外部接続用正極端子３１で電気的に接続する。同様に、同一方向を向いた全ての組電池２０の組電池用負極端子２３を、外部接続用負極端子３２で電気的に接続する。同図に示すように、外部接続用正極端子３１は、略矩形の平板形状であり、組電池用正極端子２２を挿入或いは圧入可能な直径を有する複数の端子接続用孔が加工されている。当該端子接続用孔は、積層された組電池２０の組電池用正極端子２２間のピッチに等しいピッチで加工されており、外部接続用負極端子３２にも同様に端子接続用孔が加工されている。
【００３７】
さらに、組電池用端子２２、２３が複合組電池３０の外部に露出しないように、接続された全ての組電池用端子２２、２３を覆うように、絶縁性の材料の絶縁カバー３３が具備されている。なお、図９において当該絶縁カバー３３は、説明の便宜上、透視図により描かれており、図１０には図示しない。そして、上述のように積層された６個の組電池２０は、その両側面部に平板状の連結部材３４で連結され、さらに固定ネジ３５により締結、固定される。
【００３８】
以上のように、薄型電池により所定の数を単位とした組電池を構成し、さらに当該組電池を単位として、所定の数の組電池を組み合わせて複合組電池を構成することにより、要求される容量、電圧等に適当な複合組電池を容易に得ることが可能となる。また、複雑な接続を伴うことなく複合組電池を構成するので、接続不良による、複合組電池の故障率を低減することが可能となる。さらに、複合組電池を構成する一つの薄型電池が故障或いは劣化し、当該薄型電池の交換を必要とする場合、当該薄型電池を有する組電池を容易に交換することも可能となる。
【００３９】
図１１は、車両１のフロア下に上述の複合組電池３０を車載した例を示す模式図である。車両１の移動に伴って、車内には多くの振動が発生する。同図に示すように、上述の複合組電池３０を車載することにより、当該振動により薄型電池の端子と電池外装部材との間に界面剥離が発生する可能性が著しく減少し、車両で電池を有効に活用することが可能となる。
【００４０】
なお、組電池を構成する薄型電池の数、複合組電池を構成する組電池の数、組電池を構成する薄型電池の接続方式、及び複合組電池を構成する組電池の接続方式は、上述の数及び接続方式に限定されるものではなく、要求される電気容量、電圧等から適宜その数及び接続方式（直列接続、並列接続、直列並列複合接続）を設定することが出来る。
【００４１】
第２実施形態
図１２は本発明の第２実施形態に係る薄型電池の端子導出部の拡大断面図である。なお、図１２は図１のＩＩＩ部の拡大断面図に相当する。本発明の第２実施形態に係る薄型電池１０は、第１実施形態の電池外装部材１０６、１０７に接着層１０６ｄ、１０７ｄを新たに付与したものであり、当該薄型電池１０のその他の構成要素は、第１実施形態と同様である。
【００４２】
図１２に示すように、上部電池外装部材１０６の第１の樹脂層１０６ａと金属層１０６ｂとの間に接着層１０６ｄが新たに設けられている。同様に、下部電池外装部材１０７の第１の樹脂層１０７ａと金属層１０７ｂとの間に接着層１０７ｄが新たに設けられている。当該接着層１０６ｄが非常に弱い樹脂層を形成することにより、第１の樹脂層１０６ａと金属層１０６ｂとの動吸振器としての動的バネ特性を効率的に低減する。同様に、接着層１０７ｄが、第１の樹脂層１０７ａと金属層１０７ｂとの動吸振器としての動的バネ特性を効率的に低減する。
【００４３】
この第２実施形態に係る薄型電池を単位電池として用いて、第１実施形態と同様に当該薄型電池を複数接続した組電池、当該組電池を複数接続した複合組電池、及び当該複合組電池を車両に車載することが可能である。
【００４４】
第３実施形態
図１３は本発明の第３実施形態に係る端子導出部の拡大断面図であり、図１４は図１３の端子導出部のマス−バネ系モデルであり、図１５は本発明の第３実施形態に係る端子導出部での振動伝達率スペクトルを示すグラフである。なお、図１３は図１のＩＩＩ部の拡大断面図に相当する。
【００４５】
本発明の第３実施形態に係る薄型電池１０は、第１実施形態の電池外装部材１０６の金属層１０６ｂと第１の樹脂層１０６ａとの間にさらに第３の樹脂層１０６ｅを新たに付与し、同様に下部電池外装部材１０７の金属層１０７ｂと第１の樹脂層１０７ａとの間にさらに第３の樹脂層１０７ｅを付与したものであり、当該薄型電池１０のその他の構成要素は、第１実施形態と同様である。なお、電池外装部材１０６、１０７の第１の樹脂層１０６ａ、１０７ａを、正極端子及び負極端子の近傍のみに配置されるシールフィルムとしても良い。
【００４６】
上部電池外装部材１０６の３つの樹脂層１０６ｃ、１０６ａ、１０６ｅのヤング率の関係は、第１の樹脂層１０６ａのヤング率が第２の樹脂層のヤング率に対して５〜５５％であり、第３の樹脂層１０６ｅのヤング率が第１の樹脂層１０６ｂのヤング率に対して９０〜１００％となるような関係を有している。同様に、下部電池外装部材１０７の３つの樹脂層１０７ｃ、１０７ａ、１０７ｅのヤング率の関係は、第１の樹脂層１０７ａのヤング率が第２の樹脂層１０７ｃのヤング率に対して５〜５５％であり、第３の樹脂層１０７ｅのヤング率が第１の樹脂層１０７ａのヤング率に対して９０〜１００％となるような関係を有している。
【００４７】
そして、上部電池外装部材１０６の第３の樹脂層１０６ｅは、第１の樹脂層１０６ａと直列接続され、図１４に示すように新たな第１のバネ部Ｋ’及び減衰要素Ｃ’を形成する。同様に、下部電池外装部材１０７の第３の樹脂層１０７ｅは、第１の樹脂層１０７ａと直列接続され、同図に示すように新たな第１のバネ部Ｋ’及び減衰要素Ｃ’を形成する。端子導出部１１１のマス−バネ系モデルにおいて、直列接続された新たな第１のバネ部Ｋ’及び減衰要素Ｃ’を形成することにより、第１の樹脂層１０６ａ、１０７ａと金属層１０６ｂ、１０７ｂとによる動吸振器としての動的バネ特性を効率的に低減する。
【００４８】
特に第３の樹脂層１０６ｅ、１０７ｅのヤング率が、第１の樹脂層１０６ａ、１０７ａのヤング率に対して９０〜１００％となるように設定することにより、端子導出部１１１のマスバネ系における動的バネ特性がヤング率の低い樹脂層に一方的に依存するのを防止し、端子導出部における共振周波数の移行が容易となる。
【００４９】
図１５は、第３実施形態に係る薄型電池の端子導出部における縦軸に加振振幅と応答振幅との比である振動伝達率、横軸に周波数の振動伝達率スペクトルを示す。同図に示すように、例えば、主たる加振振動数が約１００Ｈｚ以下に特に集中する車両等での薄型電池の使用する場合において、本発明の第３実施形態に係るチューニングにより、端子導出部の共振周波数を約１００Ｈｚ以上に移行させて加振振動数から離遠させることにより、加振に対する共振を防止して薄型電池を有効に活用することが可能となる。なお、加振振動数は約１００Ｈｚ以下に特に限定されず、それ以上の加振振動数に対しても、上記のチューニングを行うことが可能である。
【００５０】
この第３実施形態に係る薄型電池を単位電池として用いて、第１実施形態と同様に当該薄型電池を複数接続した組電池、当該組電池を複数接続した複合組電池、及び当該複合組電池を車両に車載することが可能である。
【００５１】
なお、以上説明した実施形態は、本発明の理解を容易にするために記載されたものであって、本発明を限定するために記載されたものではない。したがって、上記の実施形態に開示された各要素は、本発明の技術的範囲に属する全ての設計変更や均等物をも含む趣旨である。
【００５２】
【実施例】
以下、本発明をさらに具体化した実施例及び比較例により本発明の効果を確認した。以下の実施例は、上述した実施形態で用いた薄型電池の効果を確認するためのものである。
【００５３】
実施例１
実施例１の薄型電池は、正極端子に厚さ１００μｍのアルミニウム（Ａｌ）箔、負極端子に厚さ１００μｍの銅（Ｃｕ）箔、正極活性物質にマンガン酸リチウム（ＬｉＭｎＯ_２）、負極活性物質に非結晶性炭素材、電解液にプロピレンカーボネート（ＰＣ）及びエチルメチルカーボネート（ＥＭＣ）の混合液を用いた。また、第１の樹脂層に膜厚８０μｍのポリエチレン（ＰＥ）樹脂フィルム、金属層に膜厚４０μｍのアルミニウム（Ａｌ）箔、第２の樹脂層に膜厚２０μｍのナイロン樹脂フィルムを図２のように積層した高分子金属複合フィルムを上部電池外装部材及び下部電池外装部材として用いて縦１４０ｍｍ×横８０ｍｍ×厚さ４ｍｍの薄型電池を作製した。なお、第１の樹脂層のポリエチレン樹脂フィルムのヤング率は、０．０８×１０^−１０Ｎ／ｍ^２であり、第２の樹脂層のナイロン樹脂フィルムのヤング率は、０．２５×１０^−１０Ｎ／ｍ^２である。従って、第２の樹脂層のヤング率に対する第１の樹脂層のヤング率の比率は３２％であり、正極端子及び負極端子の厚さは、金属層の膜厚に対して２．５倍となった。実施例１において作製した薄型電池の条件を表１に示す。
【００５４】
【表１】

【００５５】
この薄型電池について、加速度比の測定及び平均減衰率の測定を行った。加速度比の測定は、当該薄型電池の端子の略中央部に加速度ピックアップを設定し、１０Ｈｚ、５０Ｈｚ、１００Ｈｚでそれぞれ強制加振したときに得られる応答振動の加速度値を測定した。この際、比較例に対する加速度値を基準にして比率を算出することにより加速度比を算出した。なお、実施例１に対する基準は後述する比較例１である。この加速度比は、その値が１．０のときは、実施例と比較例の加速度の絶対値が同一であることを示し、加速度比の値が０．０〜１．０のときは、強制加振に対して応答振動が低減したことを示し、加速度比の値が１．０以上のときは強制振動に共振して応答振動が増幅されたことを意味する。
【００５６】
また、平均低減率の測定は、上述の加速度比を１０〜３００Ｈｚで測定し、その低減率を平均化したものであり、数値が大きいほど、全体的に振動が低減されたことを示す。
【００５７】
この結果、表２に示すように実施例１における加速度比測定では、１０Ｈｚ：０．２７、５０Ｈｚ：０．３２、１００Ｈｚ：０．３０となり、各加振振動数において振動の低減が確認された。また、実施例１における平均低減率の測定は約５０％となり、全体として振動の低減が確認された。なお、本実施例の振動伝達スペクトルは図４に示すように、共振周波数が移行して約１００Ｈｚ以上になっていることが確認され、本実施例の第１固有振動数は比較例１の第１固有振動数に対して高周波数側への移行量は約５０Ｈｚ分移行した。
【００５８】
【表２】

【００５９】
実施例２
実施例２の薄型電池には、実施例１と同様の正極活性物質、負極活性物質、電解液を用い、正極端子に厚さ２００μｍのアルミニウム（Ａｌ）箔、負極端子に厚さ２００μｍのニッケル（Ｎｉ）箔を用いた。また、第１の樹脂層に膜厚８０μｍのポリエチレン（ＰＥ）樹脂フィルム、金属層に膜厚４０μｍのアルミニウム（Ａｌ）箔、第２の樹脂層に膜厚２０μｍのナイロン樹脂フィルム、そして第１の樹脂層と金属層との界面にウレタン系接着剤の接着層を設けた図１２に示すような高分子金属複合フィルムを上部電池外装部材及び下部電池外装部材として用いて縦１４０ｍｍ×横８０ｍｍ×厚さ４ｍｍの薄型電池を作製した。なお、第１の樹脂層のポリエチレン樹脂フィルムのヤング率は、０．０８×１０^−１０Ｎ／ｍ^２であり、第２の樹脂層のナイロン樹脂フィルムのヤング率は、０．２５×１０^−１０Ｎ／ｍ^２である。従って、第２の樹脂層のヤング率に対する第１の樹脂層のヤング率の比率は３２％であり、正極端子及び負極端子の厚さは、金属層の膜厚に対して５．０倍となった。実施例２において作製した薄型電池の条件を表１に示す。
【００６０】
この薄型電池について、第１実施例と同様の条件で、加速度比測定及び平均低減率測定を行った。その結果、表２に示すように、加速度比測定においては、基準に対して、１０Ｈｚ：０．２５、５０Ｈｚ：０．３、１００Ｈｚ：０．２９となり、各加振振動数において振動の低減が確認された。また、実施例２における平均低減率測定は約４０％となり、全体として振動の低減が確認された。なお、本実施例の第１固有振動数は比較例１の第１固有振動数に対して高周波数側に約６０Ｈｚ分移行し、約１００Ｈｚ以上に位置した。
【００６１】
実施例３
実施例３の薄型電池には、実施例１と同様の正極活性物質、負極活性物質、電解液を用い、正極端子に厚さ１００μｍのアルミニウム（Ａｌ）箔、負極端子に厚さ１００μｍの鉄（Ｆｅ）箔を用いた。また、第１の樹脂層に膜厚４０μｍの変性ポリプロピレン（ＰＰ）、金属層に膜厚５０μｍのアルミニウム（Ａｌ）箔、第２の樹脂層に膜厚２５μｍのナイロン樹脂フィルム、そして第１の樹脂層と金属層との間に膜厚４０μｍのポリプロピレン（ＰＰ）樹脂フィルムの第３の樹脂層を図１３に示すように積層した高分子金属複合フィルムを上部電池外装部材及び下部電池外装部材として用いて、縦１４０ｍｍ×横８０ｍｍ×厚さ４ｍｍの薄型電池を作製した。実施例３で作製した薄型電池の条件を表１に示す。なお、第１の樹脂層の変性ポリプロピレンのヤング率は、０．１２×１０^−１０Ｎ／ｍ^２であり、第２の樹脂層のナイロン樹脂フィルムのヤング率は、０．２５×１０^−１０Ｎ／ｍ^２であり、第３の樹脂層のポリプロピレンのヤング率は、０．１３×１０^−１０Ｎ／ｍ^２である。従って、第２の樹脂層のヤング率に対する第１の樹脂層のヤング率の比率は４８％であり、第１の樹脂層のヤング率に対する第３の樹脂層のヤング率の比率は約９２％であり、正極端子及び負極端子の厚さは、金属層の膜厚に対して２．０倍となった。実施例３において作製した薄型電池の条件を表１に示す。
【００６２】
この薄型電池について、第１実施例と同様の条件で、加速度比測定及び平均低減率測定を行った。その結果、表２に示すように、加速度比測定においては、基準に対して、１０Ｈｚ：０．３０、５０Ｈｚ：０．３５、１００Ｈｚ：０．３４となり、各加振振動数において振動の低減が確認された。また、実施例３における平均低減率測定は約４５％となり、全体として振動の低減が確認された。なお、本実施例の振動伝達スペクトルは図１５に示すように、共振周波数が移行して１００Ｈｚ以上になっていることが確認され、本実施例の第１固有振動数は比較例２の第１共振周波数に対して高周波側に約４０Ｈｚ分移行した。
【００６３】
実施例４
実施例４の薄型電池には、正極端子に厚さ２５０μｍのアルミニウム（Ａｌ）箔、負極端子に厚さ２５０μｍのニッケル（Ｎｉ）箔を用い、その他の構成要素については実施例３と同様のものを用いて、縦１４０ｍｍ×横８０ｍｍ×厚さ４ｍｍの薄型電池を作製した。実施例４で作製した薄型電池の条件を表１に示す。
【００６４】
この薄型電池について、第１実施例と同様の条件で、加速度比測定及び平均低減率測定を行った。その結果、表２に示すように、加速度比測定においては、基準に対して１０Ｈｚ：０．２７、５０Ｈｚ：０．３２、１００Ｈｚ：０．３３となり、各加振振動数において振動の低減が確認された。また、実施例４における平均低減率測定は約５０％となり、全体として振動の低減が確認された。なお、本実施例の第１共振周波数は比較例２の第１共振周波数に対して高周波数側に約８０Ｈｚ分移行し、１００Ｈｚ以上に位置した。
【００６５】
比較例１
比較例１の薄型電池は、電池外装部材の第２の樹脂層に膜厚２０μｍ、ヤング率０．１２×１０^−１０Ｎ／ｍ^２のナイロン樹脂フィルムを用い、薄型電池の他の構成要素は実施例１と同様である。なお、第２の樹脂層のヤング率に対する第１の樹脂層のヤング率の比率は約６７％である。
【００６６】
比較例２
比較例２の薄型電池は、電池外装部材の第２の樹脂層に膜厚２５μｍ、ヤング率０．１２×１０^−１０Ｎ／ｍ^２のナイロン樹脂フィルムを用い、薄型電池の他の構成要素は実施例３と同様である。なお、第２の樹脂層のヤング率に対する第１の樹脂層のヤング率の比率は約９２％である。
【００６７】
考察
実施例１〜４と比較例１、２とを比較して、共振周波数を移行させて加振周波数から離し、全体周波数において振動が低減されていることが確認され、実施例１〜４の薄型電池は印加される振動に対して強い構造を有することが明らかとなった。
【図面の簡単な説明】
【図１】図１（Ａ）は本発明の第１実施形態に係る薄型電池の全体を示す平面図、図１（Ｂ）は（Ａ）のＩＩ−ＩＩ線に沿う断面図である。
【図２】図１（Ａ）のＩＩＩ部の拡大断面図である。
【図３】図２の端子導出部のマスバネ系モデルである。
【図４】本発明の第１実施形態に係る端子導出部での振動伝達率スペクトルを示すグラフである。
【図５】本発明の第１実施形態に係る複数の薄型電池の接続構造を示す図であり、図５（Ａ）は並列接続を示し、図５（Ｂ）は比較のための直列接続を示す。
【図６】本発明の第１実施形態に係る複数の薄型電池の他の接続構造を示す図であり、図６（Ａ）は並列接続を示し、図６（Ｂ）は比較のための直列接続を示す。
【図７】本発明の第１実施形態に係る複数の薄型電池により構成される組電池の斜視図である。
【図８】図８（Ａ）は図７の組電池の平面図、図８（Ｂ）は図７の組電池の正面図、図８（Ｃ）は図７の組電池の側面図である。
【図９】図７の組電池により構成される複合組電池の斜視図である。
【図１０】図１０（Ａ）は図９の複合組電池の平面図、図１０（Ｂ）は図９の複合組電池の正面図、図１０（Ｃ）は図９の複合組電池の側面図である。
【図１１】本発明の第１実施形態に係る複合組電池を車両に搭載した模式図である。
【図１２】本発明の第２実施形態に係る端子導出部の拡大断面図である。
【図１３】本発明の第３実施形態に係る端子導出部の拡大断面図である。
【図１４】図１３のマスバネ系モデルである。
【図１５】本発明の第３実施形態に係る端子導出部での振動伝達率スペクトルを示すグラフである。
【符号の説明】
１…車両
１０…薄型電池
１０ａ…第１の薄型電池
１０ｂ…第２の薄型電池
１０１…正極板
１０２…セパレータ
１０３…負極板
１０４…正極端子
１０５…負極端子
１０６…上部電池外装部材
１０６ｃ…第２の樹脂層
１０６ｂ…金属層
１０６ａ…第１の樹脂層
１０６ｄ…接着層
１０６ｅ…第３の樹脂層
１０７…下部電池外装部材
１０７ｃ…第２の樹脂層
１０７ｂ…金属層
１０７ａ…第１の樹脂層
１０７ｄ…接着層
１０７ｅ…第３の樹脂層
１０９…発電要素
１１０…熱融着領域
１１１…端子導出部
２０…組電池
２１ａ…第１のバスバー
２１ｂ…第２のバスバー
２２…組電池用正極端子
２３…組電池用負極端子
２４…充填剤
２５…組電池用カバー
２６…外部弾性体
３０…複合組電池
３１…外部接続用正極端子
３２…外部接続用負極端子
３３…絶縁カバー
３４…連結部材
３５…固定ネジ[0001]
【Technical field】
The present invention relates to a thin battery having a terminal extending from an edge of an outer peripheral portion of a sealing means, and more particularly to a thin battery having a structure resistant to applied vibration.
[0002]
[Background Art]
With the diversification of usage modes and usage conditions of a thin battery having a terminal extending from the edge of the outer peripheral portion of the sealing means, vibration applied to the thin battery from the outside increases. Due to this vibration, the electrolyte injected into the thin battery leaks due to the peeling of a portion where the positive electrode terminal or the negative electrode terminal is led out of the battery exterior member (hereinafter, also simply referred to as a terminal lead portion), and the performance of the thin battery It may lead to a decrease.
[0003]
DISCLOSURE OF THE INVENTION
An object of the present invention is to provide a thin battery having a structure that is strong against an applied external force.
[0004]
In order to achieve the above object, according to the present invention, there is provided a sealing means having at least one metal layer sandwiched between two synthetic resin layers, and a positive electrode terminal and a negative electrode terminal are provided on the outer periphery of the sealing means. A thin battery derived from an edge of a portion, wherein the first synthetic resin layer located at the innermost layer of the sealing means has a Young's modulus of the second synthetic resin layer located at the outermost layer of the sealing means. A thin battery having a smaller Young's modulus is provided (see claim 1).
[0005]
According to the present invention, by controlling the Young's modulus of the innermost first synthetic resin layer of the battery exterior member to be smaller than the Young's modulus of the outermost second synthetic resin layer, the resonance of the terminal lead-out portion can be achieved. The frequency is shifted away from the excitation frequency to prevent resonance. Accordingly, occurrence of peeling of the terminal lead-out portion due to vibration applied from the outside can be significantly reduced, and a thin battery having a structure that is strong against applied vibration can be obtained.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1st Embodiment FIG. 1A is a plan view showing an entire thin battery according to a first embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along line II-II in FIG. It is. FIG. 2 is an enlarged sectional view of a part III in FIG. FIG. 3 shows the mass-spring system model of FIG. FIG. 4 is a graph showing a vibration transmissibility spectrum at the terminal lead-out section according to the first embodiment of the present invention. FIG. 1 shows one thin battery (unit battery), and an assembled battery having a desired voltage and capacity is formed by stacking a plurality of the thin batteries 10.
[0007]
First, the overall configuration of the thin battery 10 according to the first embodiment of the present invention will be described with reference to FIG. 1. The thin battery 10 of this example is a lithium-based thin secondary battery, and includes two positive plates 101. , Five separators 102, two negative plates 103, a positive terminal 104, a negative terminal 105, an upper battery outer member 106, a lower battery outer member 107, and an electrolyte (not shown). I have. Among these, the positive electrode plate 101, the separator 102, the negative electrode plate 103, and the electrolyte are particularly referred to as a power generation element 109.
[0008]
The number of the positive electrode plate 101, the separator 102, and the negative electrode plate 103 is not limited at all, and the power generating element 109 can be constituted by one positive electrode plate 101, three separators 102, and one negative electrode plate 104. . If necessary, the number of the positive electrode plate, the negative electrode plate, and the number of separators can be selected and configured.
[0009]
The positive electrode plate 101 constituting the power generating element 109 is composed of a positive electrode active material such as a metal oxide, a conductive material such as carbon black, and an adhesive such as an aqueous dispersion of polytetrafluoroethylene in a weight ratio of, for example, 100%. : A mixture of 3:10 was applied to both sides of a metal foil such as an aluminum foil as a positive electrode current collector, dried, rolled, and then cut into a predetermined size. The mixing ratio of the aqueous dispersion of polytetrafluoroethylene is the solid content.
[0010]
Examples of the positive electrode active material include lithium composite oxides such as lithium nickelate (LiNiO ₂ ), lithium manganate (LiMnO ₂ ), and lithium cobaltate (LiCoO ₂ ), and chalcogenide (S, Se, Te) compounds. Can be. These materials relatively easily diffuse the heat generated inside the thin battery, reduce the expansion due to the expansion of the terminal due to heat transfer to the terminal, and minimize the tensile stress transmitted from the terminal to the battery exterior member described later. It becomes.
[0011]
The negative electrode plate 103 constituting the power generation element 109 is formed of, for example, an amorphous carbon, a non-graphitizable carbon, a graphitizable carbon, or a negative electrode active material that occludes and releases lithium ions of a positive electrode active material, such as graphite. An aqueous dispersion of styrene-butadiene rubber resin powder as a precursor material for the organic fired body is mixed at, for example, a solid content ratio of 100: 5, dried, and then pulverized to carry carbonized styrene-butadiene rubber on the carbon particle surfaces. The main material is mixed with a binder such as an acrylic resin emulsion at a weight ratio of 100: 5, for example, and this mixture is used as a metal foil such as a nickel foil or a copper foil as a negative electrode current collector. Is dried, rolled, and then cut into a predetermined size.
[0012]
In particular, when amorphous carbon or non-graphitizable carbon is used as the negative electrode active material, the flatness of the potential during charge and discharge is poor, and the output voltage decreases with the amount of discharge, so it is not suitable for the power supply of communication equipment and office equipment. However, when used as a power source for an electric vehicle or the like, there is no sharp drop in output, which is advantageous.
[0013]
Further, the separator 102 of the power generation element 109 prevents short-circuit between the positive electrode plate 101 and the negative electrode plate 103 described above, and may have a function of retaining an electrolyte. The separator 102 is a microporous film made of, for example, a polyolefin such as polyethylene (PE) or polypropylene (PP). When an overcurrent flows, the heat generated by the separator 102 causes pores in the layer to be closed and cuts off the current. It also has
[0014]
Note that the separator 102 of the present invention is not limited to a single-layer film of polyolefin or the like, and a three-layer structure in which a polypropylene film is sandwiched by a polyethylene film, or a laminate of a polyolefin microporous film and an organic nonwoven fabric can also be used. . By forming the separator 102 into multiple layers, various functions such as a function of preventing an overcurrent, a function of retaining an electrolyte, and a function of maintaining the shape of the separator (improving rigidity) can be provided. Further, a gel electrolyte, an intrinsic polymer electrolyte, or the like can be used instead of the separator 102.
[0015]
The above-described power generation elements 109 are stacked in such a manner that the positive electrode plate 101 and the negative electrode plate 103 are alternately arranged from the top and the separator 102 is positioned between the positive electrode plate 101 and the negative electrode plate 103. One separator 102 is stacked on each of the upper and lower parts. Each of the two positive plates 101 is connected to a metal foil positive terminal 104 via a positive current collector 104a, while the two negative plates 103 are connected to a negative current collector 105a. Is connected to the negative electrode terminal 105 also made of metal foil. Note that the positive electrode terminal 104 and the negative electrode terminal 105 are not particularly limited as long as they are electrochemically stable metal materials. Examples of the positive electrode terminal 104 include aluminum, an aluminum alloy, copper, and nickel. May be nickel, copper, stainless steel, iron or the like. These metals are particularly suitable as components of a thin battery in terms of metal resistance, coefficient of linear expansion, and resistivity.Even when the operating temperature is changed, the tensile stress transmitted from the terminal to the battery exterior member described later is also reduced. It is possible to suppress as much as possible. Further, in each of the positive-side current collector 104a and the negative-side current collector 105a of the present example, an aluminum foil, a nickel foil, a copper foil, and an iron foil constituting the current collector of the positive electrode plate 104 and the negative electrode plate 105 are extended. However, the

current collectors

104a and 105a may be formed of separate materials and components.
[0016]
The power generation element 109 is sealed by the upper battery outer member 106 and the lower battery outer member 107 (sealing means). As shown in FIG. 2, the upper battery exterior member 106 according to the first embodiment of the present invention includes a first resin layer 106a, a metal layer 106b, and a second resin layer 106c from the inside to the outside of the thin battery 10. The three layers 106a to 106c are stacked in this order. The three layers 106a to 106c are laminated over the entire surface of the upper battery exterior member 106, and the first resin layer 106a is formed of, for example, an electrolytic solution resistant material such as polyethylene, modified polyethylene, polypropylene, modified polypropylene, and ionomer. And a resin film having excellent heat fusion properties. The second resin layer 106c is a resin film having excellent electrical insulation properties, such as a polyamide resin and a polyester resin. As described above, by forming the first resin layer of the battery exterior member from a resin such as polypropylene, modified polypropylene, polyethylene, modified polyethylene, or ionomer, the positive or negative electrode terminal made of metal and the first resin exterior member of the battery exterior member are formed. It is possible to ensure good fusion bonding with the resin layer. The metal layer 106b is, for example, a metal foil such as aluminum. Therefore, for example, the upper battery exterior member 106 is formed by laminating one surface of a metal foil such as aluminum (the inner surface of a thin battery) with a resin such as polyethylene, modified polyethylene, polypropylene, modified polypropylene, and ionomer, and then laminating the other surface ( It is formed of a flexible material such as a resin-metal thin film laminate obtained by laminating an outer surface of a thin battery) with a polyamide resin, a polyester resin, or the like. As described above, when the battery exterior member includes the metal layer in addition to the resin layer, the strength of the battery exterior member can be improved. Note that the second resin layer 106c has a thickness relatively smaller than the thickness of the metal layer 106b and the thickness of the first resin layer 106a. This makes it possible to make the characteristics of a dynamic vibration absorber described later work effectively.
[0017]
The lower battery exterior member 107 has a structure similar to that of the upper battery exterior member 106. As shown in FIG. 2, a first resin layer 107 a and a metal layer 107 b extend from the inside to the outside of the thin battery 10. The three layers 107a to 107c are stacked in this order on the second resin layer 107c. Like the first resin layer 106a of the upper battery exterior member 106, the first resin layer 107a of the lower battery exterior member 107 is made of, for example, an electrolytic solution such as polyethylene, modified polyethylene, polypropylene, modified polypropylene, and ionomer, and a heat-resistant material. It is a resin film with excellent fusion property. Like the metal layer 106b of the upper battery exterior member 106, the metal layer 107b of the lower battery exterior member 107 is, for example, a metal foil such as aluminum. Like the second resin layer 106c of the upper battery exterior member 106, the second resin layer 107c of the lower battery exterior member 107 is a resin film having excellent electrical insulation properties, such as a polyamide-based resin and a polyester-based resin. . The second resin layer 107c has a thickness relatively smaller than the thickness of the metal layer 107b and the thickness of the first resin layer 107a, and will be described later by the first resin layer 107a and the metal layer 107b. The dynamic vibration absorber characteristics can be effectively applied.
[0018]
Further, the terminal lead-out portion 111 composed of the positive terminal 104 or the negative terminal 105 and the

battery exterior members

106 and 107 shifts the resonance frequency of the terminal lead-out portion 111 away from the excitation frequency. In order to prevent resonance in the terminal lead-out section 111, a two-degree-of-freedom mass-spring system as shown in FIG. 3 is formed. Mass of Figure 3 - in spring system model, the positive electrode terminal 104 or the negative electrode terminal 105 corresponds to a first mass portion M of the mass _{m 1} of the thin battery 10, a metal layer 106b of the battery

outer members

106 and 107, 107 b is the mass m ₂ corresponds to the second mass portions Ma and Mb. Further, the first resin layer 107a of the first resin layer 106a and a lower battery case member 107 of the upper battery case member 106 corresponds to the first spring portion K and the damping element C Young's modulus k _1, battery outer member the second resin layer 106c of the 106 and 107, 107c correspond second spring portion Ka of Young's modulus _{k 2,} to Kb, the Young's modulus _{k 1} of the first spring portion K, the second spring portion Ka, Kb has a relationship of ₅ to 55% with respect to Young's modulus k2. Thus, the second spring portion Ka, by a small Young's modulus k ₁ than the Young's modulus k ₂ of the Kb first spring portion K, the first resin layer 106a is a first spring portion K, 107a and the metal layers 106b and 107b, which are the second mass portions Ma and Mb, effectively act as a dynamic vibration absorber to separate the resonance frequency of the mass-spring system of the terminal lead-out portion 111 from the excitation frequency. It is possible to shift so that If the Young's modulus k1 of the _first spring portion K is less than 5% of the Young's modulus k2 of the _second spring portions Ka and Kb, the first spring portion K and the second spring portion Ka, There is a possibility that the difference between the dynamic spring constant and Kb becomes excessive, and the structure of the terminal lead-out portion 111 becomes weak. When the Young's modulus k1 of the _first spring portion K is larger than 55% of the Young's modulus k2 of the _second spring portions Ka and Kb, the difference in the dynamic spring constant depending on the Young's modulus is small, The action of the second mass parts Ma, Mb and the first spring part K as a dynamic vibration absorber is weakened, and it is difficult to shift the resonance frequency of the terminal lead-out part 111.
[0019]
In addition, the above-described positive electrode terminal 104 and negative electrode terminal 105 have a thickness that is 2 to 5 times the thickness of the metal layers 106 b and 107 b of the

battery exterior members

106 and 107. Here, when the thickness of the positive electrode terminal 104 and the negative electrode terminal 105 is less than twice the thickness of the metal layers 106b and 107b, the influence of the metal layers 106b and 107b on the resonance frequency of the terminal lead-out portion 111 increases, There is a possibility that shifting of the resonance frequency of the terminal deriving unit 111 becomes difficult. Further, when the thickness of the positive electrode terminal 104 and the negative electrode terminal 105 is larger than five times the thickness of the metal layers 106b and 107b, the influence of the metal layers 106b and 107b on the resonance frequency of the terminal lead-out portion 111 decreases, and It becomes difficult to shift to a changing frequency.
[0020]
The resonance frequencies (natural frequencies) ω ₁ and ω ₂ in the above-described two-degree-of-freedom mass-spring system can be substantially calculated from Expression 1.
[0021]
(Equation 1)

Since the terminal lead-out part of the thin battery according to the first embodiment of the present invention is not a complete two-degree-of-freedom mass-spring system, it cannot be completely described by the above equation. Tuning of the resonance frequency in the terminal lead-out section is possible. The resonance frequency of the terminal lead-out section may be tuned by changing the mass and Young's modulus of the above equation by changing the material of each layer and the terminal.
[0022]
By manipulating the material, thickness and Young's modulus of each layer constituting the battery exterior member, and the material and thickness of the positive terminal and the negative terminal, the primary natural frequency and secondary natural frequency in the mass-spring system of the terminal lead-out part The frequency can be set arbitrarily, and the resonance frequency of the terminal lead-out portion is shifted so as to be far from the excitation frequency, so that resonance can be suppressed.
[0023]
FIG. 4 shows the vibration transmissivity, which is the ratio between the excitation amplitude and the response amplitude, on the vertical axis and the vibration transmissivity spectrum of the frequency on the horizontal axis in the terminal lead-out portion of the thin battery according to the first embodiment. As shown in the figure, for example, in the case of using a thin battery in a vehicle or the like where the main excitation frequency is particularly concentrated to about 100 Hz or less, the tuning of the terminal lead-out section is performed by tuning according to the first embodiment of the present invention. By shifting the resonance frequency to about 100 Hz or more and moving away from the vibration frequency, resonance to the vibration can be prevented and the thin battery can be used effectively. Note that the excitation frequency is not particularly limited to about 100 Hz or less, and the above-mentioned tuning can be performed for the excitation frequency higher than about 100 Hz.
[0024]
Further, as shown in FIG. 1, the positive terminal 104 is led out from one end of the sealed battery

outer casings

106 and 107. In order to maintain a sealing property in the thin battery 10, a seal made of polyethylene, polypropylene, or the like is provided at a portion where the positive electrode terminal 104 and the

battery exteriors

106 and 107 are in contact with each other. A film can be interposed by a method such as heat fusion.
[0025]
Similarly, a negative electrode terminal 105 is led out from the other end of the sealed battery

outer casings

106 and 107. Here, similarly to the positive terminal 104 side, the negative electrode terminal 105 and the battery

outer casings

106 and 107 are connected. A seal film may be interposed in a portion where the contact is made. In any of the positive electrode terminal 104 and the negative electrode terminal 105, it is preferable that the seal film is formed of the same resin as the resin forming the

battery casings

106 and 107 from the viewpoint of heat fusion.
[0026]
These

battery exterior members

106 and 107 wrap the above-described power generation element 109, the positive-side current collector 104 a, a part of the positive terminal 104, and the negative-side current collector 105 a and a part of the negative terminal 105. After injecting a liquid electrolyte in which a lithium salt such as lithium perchlorate or lithium borofluoride is dissolved in an organic liquid solvent into a space formed by 106 and 107, the outside of the upper battery exterior member 106 and the lower battery exterior member 107 is injected. The peripheral heat-sealed region 110 is heat-sealed by a hot press and sealed.
[0027]
It is preferable that the thin battery 10 sealed in this way has a total thickness of 1 to 10 [mm]. By setting the thickness of the thin battery to 10 mm or less, heat is hardly trapped inside the thin battery, the possibility of transmitting stress to the interface of the battery exterior member is reduced, and the effect of thermal degradation of the battery is reduced. Is also reduced. Further, by setting the thickness of the thin battery to 1 mm or more, a sufficient capacity can be secured, and economic efficiency can be increased.
[0028]
Examples of the organic liquid solvent include ester solvents such as propylene carbonate (PC), ethylene carbonate (EC), and dimethyl carbonate (DMC). However, the organic liquid solvent of the present invention is not limited thereto. An organic liquid solvent obtained by mixing and preparing an ether-based solvent such as γ-butylactone (γ-BL), diethoxyethane (DEE) or the like with an ester-based solvent can also be used.
[0029]
Hereinafter, an assembled battery formed by combining a plurality of the above-described thin batteries and a composite assembled battery formed by combining a plurality of the assembled batteries will be described.
[0030]
5A and 5B are diagrams showing a method for connecting a plurality of thin batteries according to the first embodiment of the present invention. FIG. 5A shows a parallel connection, and FIG. 5B shows a series connection for comparison. . 6A and 6B are diagrams showing another connection method of the plurality of thin batteries according to the first embodiment of the present invention. FIG. 6A shows a parallel connection, and FIG. 6B shows a series connection for comparison. Is shown. FIG. 7 is a perspective view of an assembled battery including a plurality of thin batteries according to the first embodiment of the present invention, FIG. 8A is a plan view of the assembled battery of FIG. 7, and FIG. 8 (C) is a side view of the assembled battery of FIG. 7, FIG. 9 is a perspective view of a combined assembled battery including the assembled battery of FIG. 7, and FIG. 10 (A) is a composite of FIG. 10 (B) is a front view of the composite battery pack of FIG. 9, FIG. 10 (C) is a side view of the composite battery pack of FIG. 9, and FIG. 11 relates to the first embodiment of the present invention. The schematic diagram which mounted the composite battery pack in the vehicle is shown.
[0031]
When the above-described thin batteries 10 are electrically connected to form a battery pack 20 having a plurality of thin batteries 10, two connection structures with the arrangements shown in FIGS. 5A and 6A are particularly applicable. A stronger structure is added to the applied external force.
[0032]
The first connection structure is, as shown in FIG. 5A, a direction in which the positive electrode terminal 104 of the first thin battery 10a and the positive terminal 104 of the second thin battery 10b are led out in the same direction. Thus, the first thin battery 10a and the second thin battery 10b are juxtaposed substantially on the same plane. Then, the positive terminal 104 of the first thin battery 10a and the positive terminal 104 of the second thin battery 10b are electrically connected by the first bus bar 21a. The negative terminal 105 of the first thin battery 10a and the negative terminal 105 of the second thin battery 10b are electrically connected by the second bus bar 21b.
[0033]
The second connection structure is, as shown in FIG. 6A, a direction in which the positive terminal 104 of the first thin battery 10a and the positive terminal 104 of the second thin battery 10b are led out in the same direction. Then, the first thin battery 10a and the second thin battery 10b are stacked by bringing the vertically upward surface of the first thin battery 10a into contact with the vertically downward surface of the second thin battery 10b. Then, the positive terminal 104 of the first thin battery 10a and the positive terminal 104 of the second thin battery 10b are welded and electrically connected, and similarly, the negative terminal 105 of the first thin battery 10a is connected to the second terminal. The negative electrode terminal 105 of the thin battery 10b is welded and electrically connected.
[0034]
When connected in series as shown in FIG. 5 (B) and FIG. 6 (B), opposite phases of torsion are applied to the positive terminals 104 of the

thin batteries

10 a and 10 b by the applied external force (FIG. 5 (B) 6B, the direction of the twist is indicated by an arrow.) On the other hand, in the connection structure described above, the positive terminals 104 and the negative terminals 105 of the

thin batteries

10a and 10b are connected. Therefore, the stress generated in each of the

thin batteries

10a and 10b has the same phase, the torsion generated in the

terminals

104 and 105 can be suppressed as much as possible, and the possibility that the interface between the terminal and the battery exterior member is peeled is low. Become. Further, when the metal of the positive electrode terminal is different from the metal of the negative electrode terminal, the tensile stress generated in the terminal lead-out part is also different, which may cause interface delamination. It is possible to make the tensile stress generated in the portion substantially equal.
[0035]
FIGS. 7 and 8A to 8C show an assembled battery 20 including, for example, 24 thin batteries 10 connected in parallel using the above-described two connection structures. The assembled battery 20 includes 24 thin batteries 10, assembled

battery terminals

22 and 23, and an assembled battery cover 25. Although not particularly shown, the same-polarity terminals of each thin battery 10 are connected in parallel by the bus bars 21a and 21b in the above-described connection structure, and the first bus bar 21a for connecting each positive electrode terminal 104 is provided with a battery pack cover. 25 is connected to a positive electrode terminal 22 for a battery assembly having a substantially cylindrical shape derived from the positive electrode terminal 25. Similarly, the second bus bar 21 b connecting each of the negative electrode terminals 105 is connected to a substantially cylindrical negative electrode terminal 23 for a battery assembly that is derived from the battery cell cover 25. When these connections are completed and the 24 thin batteries 10 are inserted into the assembled battery cover 25, the space formed between the assembled battery cover 25 and the other components of the assembled battery 20 is removed. Filler 24 is filled and sealed. Further, when thin batteries are stacked as a composite battery to be described later, external elastic bodies 26 are attached to the lower four corners of the battery pack cover 25 in order to minimize vibration between the thin batteries.
[0036]
FIGS. 9 and 10A to 10C show a composite battery pack 30 including six battery packs 20 electrically connected to the battery pack 20 shown in FIG. As shown in FIGS. 9 and 10A to 10C, the composite battery pack 30 is stacked such that the

terminals

22 and 23 of the battery pack 20 face the same direction. That is, the

terminals

22 and 23 of the assembled battery 20 located at the m-th stage and the

terminals

22 and 23 of the assembled battery 20 located at the (m + 1) -th stage face in the same direction. Then, the assembled battery 20 of the (m + 1) th stage is stacked (m: natural number). Then, the battery pack positive terminals 22 of all the battery packs 20 facing in the same direction are electrically connected by the external connection positive terminal 31 connecting the composite battery pack 30 to the outside. Similarly, the assembled battery negative terminals 23 of all the assembled batteries 20 facing in the same direction are electrically connected by the external connection negative terminal 32. As shown in the figure, the external connection positive terminal 31 has a substantially rectangular flat plate shape, and has a plurality of terminal connection holes having a diameter capable of inserting or press-fitting the assembled battery positive terminal 22. The terminal connection holes are formed at a pitch equal to the pitch between the assembled battery positive terminals 22 of the stacked battery assembly 20, and the terminal connection holes are similarly formed in the external connection negative terminal 32. I have.
[0037]
Further, an insulating cover 33 made of an insulating material is provided to cover all the

connected battery terminals

22 and 23 so that the

battery terminals

22 and 23 are not exposed to the outside of the composite battery 30. ing. Note that, in FIG. 9, the insulating cover 33 is illustrated in a perspective view for convenience of description, and is not illustrated in FIG. Then, the six assembled batteries 20 stacked as described above are connected to both side surfaces thereof by flat connecting members 34, and further fastened and fixed by fixing screws 35.
[0038]
As described above, this is required by configuring a battery pack in units of a predetermined number of thin batteries and further combining the battery packs of a predetermined number in units of the battery pack to form a composite battery pack. A composite battery pack suitable for capacity, voltage, and the like can be easily obtained. In addition, since the composite battery pack is configured without complicated connection, the failure rate of the composite battery pack due to poor connection can be reduced. Furthermore, when one of the thin batteries constituting the composite battery is broken or deteriorated and the thin battery needs to be replaced, the battery having the thin battery can be easily replaced.
[0039]
FIG. 11 is a schematic diagram showing an example in which the above-described composite battery pack 30 is mounted below the floor of the vehicle 1. As the vehicle 1 moves, many vibrations are generated inside the vehicle. As shown in the figure, by mounting the above-mentioned composite battery pack 30 on the vehicle, the possibility that interfacial separation occurs between the terminal of the thin battery and the battery exterior member due to the vibration is significantly reduced. It can be used effectively.
[0040]
The number of thin batteries constituting the assembled battery, the number of assembled batteries constituting the composite battery, the connection method of the thin batteries constituting the assembled battery, and the connection method of the assembled batteries constituting the composite battery are as described above. The number and connection method are not limited, and the number and connection method (series connection, parallel connection, series / parallel composite connection) can be appropriately set based on required electric capacity, voltage, and the like.
[0041]
Second Embodiment FIG. 12 is an enlarged sectional view of a terminal lead-out portion of a thin battery according to a second embodiment of the present invention. FIG. 12 corresponds to an enlarged sectional view of a portion III in FIG. The thin battery 10 according to the second embodiment of the present invention is obtained by newly providing

adhesive layers

106d and 107d to the

battery exterior members

106 and 107 of the first embodiment, and other components of the thin battery 10 are as follows. , And the same as in the first embodiment.
[0042]
As shown in FIG. 12, an adhesive layer 106d is newly provided between the first resin layer 106a and the metal layer 106b of the upper battery exterior member 106. Similarly, an adhesive layer 107d is newly provided between the first resin layer 107a and the metal layer 107b of the lower battery exterior member 107. Since the adhesive layer 106d forms a very weak resin layer, the dynamic spring characteristics of the first resin layer 106a and the metal layer 106b as a dynamic vibration absorber are efficiently reduced. Similarly, the adhesive layer 107d efficiently reduces the dynamic spring characteristics of the first resin layer 107a and the metal layer 107b as a dynamic vibration absorber.
[0043]
Using the thin battery according to the second embodiment as a unit battery, as in the first embodiment, an assembled battery in which a plurality of thin batteries are connected, a composite assembled battery in which a plurality of assembled batteries are connected, and a composite assembled battery It can be mounted on a vehicle.
[0044]
Third Embodiment FIG. 13 is an enlarged sectional view of a terminal lead-out part according to a third embodiment of the present invention, and FIG. 14 is a mass-spring system model of the terminal lead-out part of FIG. 9 is a graph showing a vibration transmissibility spectrum at a terminal lead-out unit according to a third embodiment of the present invention. FIG. 13 corresponds to an enlarged sectional view of a part III in FIG.
[0045]
In the thin battery 10 according to the third embodiment of the present invention, a third resin layer 106e is additionally provided between the metal layer 106b and the first resin layer 106a of the battery exterior member 106 of the first embodiment. Similarly, a third resin layer 107e is further provided between the metal layer 107b of the lower battery exterior member 107 and the first resin layer 107a, and the other components of the thin battery 10 are the first This is the same as the embodiment. Note that the

first resin layers

106a and 107a of the

battery exterior members

106 and 107 may be a seal film disposed only near the positive terminal and the negative terminal.
[0046]
The relationship between the Young's modulus of the three

resin layers

106c, 106a, and 106e of the upper battery exterior member 106 is such that the Young's modulus of the first resin layer 106a is 5 to 55% with respect to the Young's modulus of the second resin layer. The relationship is such that the Young's modulus of the third resin layer 106e is 90 to 100% with respect to the Young's modulus of the first resin layer 106b. Similarly, the relationship between the Young's modulus of the three

resin layers

107c, 107a, and 107e of the lower battery exterior member 107 is such that the Young's modulus of the first resin layer 107a is 5 to 55 with respect to the Young's modulus of the second resin layer 107c. % So that the Young's modulus of the third resin layer 107e is 90 to 100% with respect to the Young's modulus of the first resin layer 107a.
[0047]
Then, the third resin layer 106e of the upper battery exterior member 106 is connected in series with the first resin layer 106a to form a new first spring portion K 'and a damping element C' as shown in FIG. . Similarly, the third resin layer 107e of the lower battery exterior member 107 is connected in series with the first resin layer 107a to form a new first spring portion K ′ and a damping element C ′ as shown in FIG. I do. In the mass-spring system model of the terminal lead-out section 111, by forming a new first spring section K 'and damping element C' connected in series, the

first resin layers

106a and 107a and the metal layers 106b and 107b are formed. This effectively reduces the dynamic spring characteristics as a dynamic vibration absorber.
[0048]
In particular, by setting the Young's modulus of the

third resin layers

106e and 107e to be 90 to 100% with respect to the Young's modulus of the

first resin layers

106a and 107a, the dynamics of the terminal lead-out portion 111 in the mass spring system can be improved. The characteristic spring characteristic is prevented from being unilaterally dependent on the resin layer having a low Young's modulus, and the transition of the resonance frequency in the terminal lead-out portion is facilitated.
[0049]
FIG. 15 shows the vibration transmissibility, which is the ratio between the vibration amplitude and the response amplitude, on the vertical axis and the vibration transmissivity spectrum of the frequency on the horizontal axis in the terminal lead-out portion of the thin battery according to the third embodiment. As shown in the figure, for example, in the case of using a thin battery in a vehicle or the like whose main vibration frequency is particularly concentrated to about 100 Hz or less, the tuning of the terminal lead-out section is performed by tuning according to the third embodiment of the present invention. By shifting the resonance frequency to about 100 Hz or more and moving away from the vibration frequency, resonance to the vibration can be prevented and the thin battery can be used effectively. Note that the excitation frequency is not particularly limited to about 100 Hz or less, and the above-mentioned tuning can be performed for the excitation frequency higher than about 100 Hz.
[0050]
Using the thin battery according to the third embodiment as a unit battery, as in the first embodiment, an assembled battery in which a plurality of thin batteries are connected, a composite assembled battery in which a plurality of assembled batteries are connected, and a composite assembled battery It can be mounted on a vehicle.
[0051]
The embodiments described above are described for facilitating the understanding of the present invention, and are not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.
[0052]
【Example】
Hereinafter, the effects of the present invention were confirmed by Examples and Comparative Examples that further embody the present invention. The following example is for confirming the effect of the thin battery used in the above-described embodiment.
[0053]
Example 1
The thin battery of Example 1 has an aluminum (Al) foil having a thickness of 100 μm for the positive electrode terminal, a copper (Cu) foil having a thickness of 100 μm for the negative electrode terminal, lithium manganate (LiMnO ₂ ) for the positive electrode active material, and a negative electrode active material. A mixed solution of propylene carbonate (PC) and ethyl methyl carbonate (EMC) was used as an amorphous carbon material and an electrolytic solution. As shown in FIG. 2, a polyethylene (PE) resin film having a thickness of 80 μm is formed on the first resin layer, an aluminum (Al) foil having a thickness of 40 μm is formed on the metal layer, and a nylon resin film having a thickness of 20 μm is formed on the second resin layer. Using the polymer / metal composite film laminated as above as an upper battery exterior member and a lower battery exterior member, a thin battery having a length of 140 mm, a width of 80 mm, and a thickness of 4 mm was produced. The Young's modulus of the polyethylene resin film of the first resin layer was 0.08 × 10 ⁻¹⁰ N / m ² , and the Young's modulus of the nylon resin film of the second resin layer was 0.25 × 10 ^{− 10} N / m ² . Therefore, the ratio of the Young's modulus of the first resin layer to the Young's modulus of the second resin layer is 32%, and the thickness of the positive electrode terminal and the negative electrode terminal is 2.5 times the thickness of the metal layer. became. Table 1 shows the conditions of the thin battery manufactured in Example 1.
[0054]
[Table 1]

[0055]
For this thin battery, the measurement of the acceleration ratio and the measurement of the average decay rate were performed. In the measurement of the acceleration ratio, an acceleration pickup was set at approximately the center of the terminal of the thin battery, and the acceleration value of the response vibration obtained when each of the terminals was forcibly excited at 10 Hz, 50 Hz, and 100 Hz was measured. At this time, the acceleration ratio was calculated by calculating the ratio based on the acceleration value for the comparative example. The reference for Example 1 is Comparative Example 1 described later. When the acceleration ratio is 1.0, it indicates that the absolute values of the acceleration of the embodiment and the comparative example are the same, and when the value of the acceleration ratio is 0.0 to 1.0, It indicates that the response vibration has been reduced in response to the excitation. When the value of the acceleration ratio is 1.0 or more, it means that the response vibration has been amplified by resonating with the forced vibration.
[0056]
In the measurement of the average reduction rate, the above-described acceleration ratio was measured at 10 to 300 Hz, and the reduction rates were averaged. The larger the numerical value, the lower the vibration as a whole.
[0057]
As a result, as shown in Table 2, in the acceleration ratio measurement in Example 1, it was 10 Hz: 0.27, 50 Hz: 0.32, 100 Hz: 0.30, and it was confirmed that the vibration was reduced at each excitation frequency. . The measurement of the average reduction rate in Example 1 was about 50%, and it was confirmed that the vibration was reduced as a whole. As shown in FIG. 4, it was confirmed that the resonance frequency of the vibration transmission spectrum of the present example shifted to about 100 Hz or higher, and the first natural frequency of the present example was the same as that of Comparative Example 1. The shift to the higher frequency side for one natural frequency shifted by about 50 Hz.
[0058]
[Table 2]

[0059]
Example 2
For the thin battery of Example 2, the same positive electrode active material, negative electrode active material, and electrolytic solution as in Example 1 were used, and a 200 μm thick aluminum (Al) foil was used for the positive electrode terminal, and a 200 μm thick nickel ( Ni) foil was used. In addition, a polyethylene (PE) resin film having a thickness of 80 μm for the first resin layer, an aluminum (Al) foil having a thickness of 40 μm for the metal layer, a nylon resin film having a thickness of 20 μm for the second resin layer, and a first resin layer. Using a polymer-metal composite film having an adhesive layer of a urethane-based adhesive at the interface between a resin layer and a metal layer as shown in FIG. 12 as an upper battery outer member and a lower battery outer member, 140 mm long × 80 mm wide × thick A thin battery having a thickness of 4 mm was manufactured. The Young's modulus of the polyethylene resin film of the first resin layer was 0.08 × 10 ⁻¹⁰ N / m ² , and the Young's modulus of the nylon resin film of the second resin layer was 0.25 × 10 ^{− 10} N / m ² . Therefore, the ratio of the Young's modulus of the first resin layer to the Young's modulus of the second resin layer is 32%, and the thickness of the positive electrode terminal and the negative electrode terminal is 5.0 times the thickness of the metal layer. became. Table 1 shows the conditions of the thin battery manufactured in Example 2.
[0060]
The acceleration ratio measurement and the average reduction rate measurement were performed on the thin battery under the same conditions as in the first example. As a result, as shown in Table 2, in the acceleration ratio measurement, 10 Hz: 0.25, 50 Hz: 0.3, and 100 Hz: 0.29 were obtained with respect to the reference, and the vibration was reduced at each excitation frequency. confirmed. In addition, the average reduction rate measurement in Example 2 was about 40%, and a reduction in vibration was confirmed as a whole. Note that the first natural frequency of the present example shifted by about 60 Hz to the higher frequency side with respect to the first natural frequency of Comparative Example 1, and was located at about 100 Hz or more.
[0061]
Example 3
For the thin battery of Example 3, the same positive electrode active material, negative electrode active material, and electrolytic solution as those of Example 1 were used, and a 100 μm thick aluminum (Al) foil was used for the positive electrode terminal, and a 100 μm thick iron ( Fe) foil was used. Also, a modified polypropylene (PP) having a thickness of 40 μm for the first resin layer, an aluminum (Al) foil having a thickness of 50 μm for the metal layer, a nylon resin film having a thickness of 25 μm for the second resin layer, and a first resin A polymer-metal composite film obtained by laminating a third resin layer of a polypropylene (PP) resin film having a thickness of 40 μm between the layer and the metal layer as shown in FIG. 13 is used as an upper battery outer member and a lower battery outer member. Thus, a thin battery having a length of 140 mm, a width of 80 mm, and a thickness of 4 mm was produced. Table 1 shows the conditions of the thin battery manufactured in Example 3. The modified resin of the first resin layer has a Young's modulus of 0.12 × 10 ⁻¹⁰ N / m ² , and the nylon resin film of the second resin layer has a Young's modulus of 0.25 × 10 ^−10. N / m ² , and the Young's modulus of the polypropylene in the third resin layer is 0.13 × 10 ⁻¹⁰ N / m ² . Accordingly, the ratio of the Young's modulus of the first resin layer to the Young's modulus of the second resin layer is 48%, and the ratio of the Young's modulus of the third resin layer to the Young's modulus of the first resin layer is about 92%. The thickness of the positive electrode terminal and the negative electrode terminal was 2.0 times the thickness of the metal layer. Table 1 shows the conditions of the thin battery manufactured in Example 3.
[0062]
The acceleration ratio measurement and the average reduction rate measurement were performed on the thin battery under the same conditions as in the first example. As a result, as shown in Table 2, in the acceleration ratio measurement, 10 Hz: 0.30, 50 Hz: 0.35, and 100 Hz: 0.34 with respect to the reference, and the vibration was reduced at each excitation frequency. confirmed. In addition, the average reduction rate measurement in Example 3 was about 45%, and it was confirmed that the vibration was reduced as a whole. As shown in FIG. 15, it was confirmed that the resonance frequency of the vibration transmission spectrum of the present example shifted to 100 Hz or higher, and the first natural frequency of the present example was the first natural frequency of Comparative Example 2. The frequency was shifted to the high frequency side by about 40 Hz with respect to the resonance frequency.
[0063]
Example 4
The thin battery of Example 4 uses an aluminum (Al) foil with a thickness of 250 μm for the positive electrode terminal and a nickel (Ni) foil with a thickness of 250 μm for the negative electrode terminal, and the other components are the same as those in Example 3. Was used to produce a thin battery having a length of 140 mm, a width of 80 mm and a thickness of 4 mm. Table 1 shows the conditions of the thin battery manufactured in Example 4.
[0064]
The acceleration ratio measurement and the average reduction rate measurement were performed on the thin battery under the same conditions as in the first example. As a result, as shown in Table 2, in the acceleration ratio measurement, it was 10 Hz: 0.27, 50 Hz: 0.32, and 100 Hz: 0.33 with respect to the reference, and it was confirmed that the vibration was reduced at each excitation frequency. Was done. In addition, the average reduction rate measurement in Example 4 was about 50%, and a reduction in vibration was confirmed as a whole. Note that the first resonance frequency of the present example shifted to a higher frequency side by about 80 Hz from the first resonance frequency of Comparative Example 2, and was located at 100 Hz or more.
[0065]
Comparative Example 1
The thin battery of Comparative Example 1 uses a nylon resin film having a thickness of 20 μm and a Young's modulus of 0.12 × 10 ⁻¹⁰ N / m ² for the second resin layer of the battery exterior member. This is similar to the first embodiment. The ratio of the Young's modulus of the first resin layer to the Young's modulus of the second resin layer is about 67%.
[0066]
Comparative Example 2
The thin battery of Comparative Example 2 uses a nylon resin film having a thickness of 25 μm and a Young's modulus of 0.12 × 10 ⁻¹⁰ N / m ² for the second resin layer of the battery exterior member. This is the same as the third embodiment. The ratio of the Young's modulus of the first resin layer to the Young's modulus of the second resin layer is about 92%.
[0067]
Consideration By comparing Examples 1 to 4 with Comparative Examples 1 and 2, it was confirmed that the resonance frequency was shifted away from the excitation frequency and the vibration was reduced at the entire frequency. It became clear that the thin batteries of Nos. 1 to 4 have a structure that is strong against applied vibration.
[Brief description of the drawings]
FIG. 1A is a plan view showing an entire thin battery according to a first embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along line II-II of FIG.
FIG. 2 is an enlarged sectional view of a part III in FIG.
FIG. 3 is a mass spring system model of a terminal lead-out unit of FIG. 2;
FIG. 4 is a graph showing a vibration transmissibility spectrum at a terminal lead-out section according to the first embodiment of the present invention.
5A and 5B are diagrams showing a connection structure of a plurality of thin batteries according to the first embodiment of the present invention. FIG. 5A shows a parallel connection, and FIG. 5B shows a series connection for comparison. Show.
6A and 6B are diagrams showing another connection structure of the plurality of thin batteries according to the first embodiment of the present invention, wherein FIG. 6A shows a parallel connection, and FIG. 6B shows a series connection for comparison. Indicates a connection.
FIG. 7 is a perspective view of an assembled battery including a plurality of thin batteries according to the first embodiment of the present invention.
8A is a plan view of the battery pack of FIG. 7, FIG. 8B is a front view of the battery pack of FIG. 7, and FIG. 8C is a side view of the battery pack of FIG. .
FIG. 9 is a perspective view of a composite battery pack including the battery pack of FIG. 7;
10 (A) is a plan view of the composite battery pack of FIG. 9, FIG. 10 (B) is a front view of the composite battery pack of FIG. 9, and FIG. 10 (C) is a side view of the composite battery pack of FIG. FIG.
FIG. 11 is a schematic diagram illustrating a state where the composite battery pack according to the first embodiment of the present invention is mounted on a vehicle.
FIG. 12 is an enlarged sectional view of a terminal lead-out portion according to a second embodiment of the present invention.
FIG. 13 is an enlarged sectional view of a terminal lead-out portion according to a third embodiment of the present invention.
FIG. 14 is a mass spring system model of FIG. 13;
FIG. 15 is a graph showing a vibration transmissibility spectrum at a terminal lead-out part according to a third embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Vehicle 10 ... Thin battery 10a ... First thin battery 10b ... Second thin battery 101 ... Positive electrode plate 102 ... Separator 103 ... Negative electrode plate 104 ... Positive electrode terminal 105 ... Negative electrode terminal 106 ... Upper battery exterior member 106c ... Second Resin layer 106b metal layer 106a first resin layer 106d adhesive layer 106e third resin layer 107 lower battery exterior member 107c second resin layer 107b metal layer 107a first resin layer 107d ... adhesive layer 107e ... third resin layer 109 ... power generation element 110 ... heat fusion region 111 ... terminal lead-out part 20 ... assembled battery 21a ... first bus bar 21b ... second bus bar 22 ... assembled battery positive terminal 23 ... Negative electrode terminal 24 for battery assembly Filler 25 Cover for battery assembly 26 Elastic body 30 Composite battery 31 Positive terminal for external connection 32 Negative terminal 33 for external connection Insulation cover 34 ... connecting member 35 ... fixing screw

Claims

Sealing means having at least one metal layer sandwiched between two synthetic resin layers,
A thin battery in which a positive electrode terminal and a negative electrode terminal are derived from an edge of an outer peripheral portion of the sealing means,
A thin battery in which the first synthetic resin layer located at the innermost layer of the sealing means has a Young's modulus smaller than that of the second synthetic resin layer located at the outermost layer of the sealing means.

2. The thin battery according to claim 1, wherein the second synthetic resin layer has the smallest thickness among the synthetic resin layer and the metal layer included in the sealing unit. 3.

The thin battery according to claim 1, wherein the first synthetic resin layer has a Young's modulus of 5 to 55% with respect to the Young's modulus of the second synthetic resin layer.

The thin battery according to any one of claims 1 to 3, wherein the positive electrode terminal and the negative electrode terminal have a thickness 2 to 5 times the thickness of the metal layer.

The thin battery according to claim 1, further comprising an adhesive layer between the metal layer and the first synthetic resin layer.

The thin battery according to any one of claims 1 to 5, wherein the sealing means further includes a third resin layer between the metal layer and the first synthetic resin layer.

The thin battery according to claim 6, wherein the third synthetic resin layer has a Young's modulus of 90 to 100% with respect to the Young's modulus of the first synthetic resin layer.

The thin battery according to any one of claims 1 to 7, wherein the first synthetic resin layer has a material selected from the group consisting of polypropylene, modified polypropylene, polyethylene, modified polyethylene, and ionomer.

The thin battery according to any one of claims 1 to 8, wherein the positive electrode terminal includes one or more components selected from the group consisting of aluminum, iron, and nickel.

The thin battery according to any one of claims 1 to 9, wherein the negative electrode terminal includes one or more components selected from the group consisting of iron, nickel, and copper.

The thin battery according to claim 1, having a thickness of 1 to 10 mm.

Having a positive electrode active material that functions as a positive electrode,
The thin battery according to claim 1, wherein the positive electrode active material is a lithium composite oxide.

The thin battery according to claim 12, wherein the lithium composite oxide is a lithium-manganese composite oxide.

Having a negative electrode active material that functions as a negative electrode,
The thin battery according to any one of claims 1 to 13, wherein the negative electrode active material is a carbon-based material.

The thin battery according to claim 14, wherein the carbon-based material is an amorphous carbon material.

A plurality of thin batteries electrically connected to the thin batteries according to any one of claims 1 to 15,
A battery pack comprising: a plurality of connection means electrically connecting one of a positive electrode terminal or a negative electrode terminal of one of the thin batteries and one of the same or another electrode terminal of another of the thin batteries. ,
The other thin batteries are juxtaposed beside the one thin battery so that the positive terminal of the one thin battery and the same terminal of the other thin battery are in the same direction,
The one connecting means electrically connects the positive electrode terminal of the one thin battery and the same electrode terminal of the other thin battery,
An assembled battery including at least two or more thin batteries in which a negative electrode terminal of the one thin battery and a same-polarity terminal of the other thin battery are electrically connected by another connecting means.

An assembled battery comprising a plurality of thin batteries electrically connected to the thin batteries according to any one of claims 1 to 15,
The other thin battery is stacked on the upper part in the vertical direction of the one thin battery so that the positive electrode terminal of the one thin battery and the same electrode terminal of the other thin battery are in the same direction,
The positive electrode terminal of the one thin battery and the same electrode terminal of the other thin battery are electrically connected,
An assembled battery including at least two or more thin batteries in which a negative electrode terminal of the one thin battery and a same-polarity terminal of the other thin battery are electrically connected.

A composite battery pack comprising a plurality of battery packs electrically connected to the battery pack according to claim 16,
Each of the assembled batteries has an assembled battery positive terminal and an assembled battery negative terminal that are electrically connected to the outside,
A composite including at least two or more of the assembled batteries in which one of the assembled battery positive electrode terminal or the assembled battery negative terminal is electrically connected to the assembled battery other electrode terminal of the other assembled battery. Battery pack.

A decoding battery pack comprising a plurality of battery packs electrically connected to the battery pack according to claim 16 or 17,
Each of the assembled batteries has an assembled battery positive terminal and an assembled battery negative terminal that are electrically connected to the outside,
The battery pack positive electrode terminal of one of the battery packs is electrically connected to the battery pack negative electrode terminal of the other battery pack,
A composite battery pack including at least two or more of the battery packs, wherein the battery pack negative electrode terminal of the one battery pack and the battery pack negative electrode terminal of the other battery pack are electrically connected.

A vehicle on which the composite battery pack according to claim 18 or 19 is mounted.