JP4107054B2

JP4107054B2 - Thin battery

Info

Publication number: JP4107054B2
Application number: JP2002325551A
Authority: JP
Inventors: 宇貴上島; 健一酒井
Original assignee: Nissan Motor Co Ltd
Current assignee: Nissan Motor Co Ltd
Priority date: 2002-11-08
Filing date: 2002-11-08
Publication date: 2008-06-25
Anticipated expiration: 2022-11-08
Also published as: JP2004158395A

Description

【０００１】
【技術分野】
本発明は、電池外装内に発電要素が収容され、電極端子及び電圧検出線を有する薄型二次電池に関する。
【０００２】
【背景技術】
薄型電池は、小型軽量であるため、これを複数接続して組電池にすることで高電圧化および高容量化することができる（たとえば特許文献１参照）。そして、こうした組電池には、それぞれの薄型電池の電圧を検出するための電圧検出線が設けられ、さらに組電池を監視および制御するための電池制御基板(セルコントローラ)も設けられている。
【０００３】
ところで、従来の電圧検出線は電極端子またはこれに接続される外部端子にネジなどを用いて電気的に接続されていた。このため、この電圧検出線を電極端子などに接続する工程が別途必要となり製造工程がそのぶんだけ長くなるといった問題があった。
【０００４】
【特許文献１】
特開平９−２５９８５９号公報
【０００５】
【発明の開示】
本発明は、電圧検出線の製造工程を簡素化できる薄型電池を提供することを目的とする。
【０００６】
上記目的を達成するために、本発明によれば、導電性フィルムの両主面に絶縁性フィルムが積層された一対の電池外装と、前記一対の電池外装の外周縁を封止して内部に収容された発電要素と、前記発電要素の電極に接続され前記電池外装の外周縁から導出された電極端子とを有する薄型電池において、前記電池外装の導電性フィルムと前記電極とを部分的に導通させる導通部と、前記導通部及び前記導電性フィルムを介して前記電極に電気的に接続されて、前記電極の電圧を検出する電圧検出線とを有する薄型電池が提供される。
【０００７】
本発明では、電池外装の導電性フィルムを利用して、電圧の検出対象である電極に導電性フィルムを介して電圧検出線を接続する。電圧検出線の接続端部は、一対の電池外装の周縁部を封止する際に当該周縁部により狭持されるので、封止工程にて電圧検出線の接続を行うことができる。
【０００８】
【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。
図１は本発明の実施形態に係る電池外装の一方（下部電池外装１０７）を示す分解斜視図、図２は本発明の実施形態に係る電圧検出線の接続端部を示す分解斜視図、図３は本発明の実施形態に係る電圧検出線の接続端部と電池外装の切欠部との接続構造を示す断面図、図４は本発明の実施形態に係る薄型電池を示す分解斜視図、図５は本発明の実施形態に係る電池外装と電極との接続部分（導電部）を示す断面図、図６は本発明の実施形態に係る薄型電池の完成状態を示す斜視図、図７は本発明の実施形態に係る薄型電池を示す分解断面図、図８は本発明の実施形態に係る薄型電池を示す断面図である。
【０００９】
図４及び図６〜図８を参照しながら本実施形態の薄型電池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、１枚の正極板１０１と、電解質１０２と、１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１０６と、下部電池外装１０７とから構成されている。このうちの正極板１０１，電解質１０２，負極板１０３およびを特に発電要素１０９と称する。
【００１０】
なお、正極板１０１，電解質１０２，負極板１０３の枚数には何ら限定されず、必要に応じて複数枚の正極板１０１及び負極板１０４でも発電要素１０９を構成することができる。
【００１１】
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。
【００１２】
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。
【００１３】
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。
【００１４】
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。
【００１５】
正極板１０１は、正極側集電部を介して、金属箔製の正極端子１０４に接続される一方で、負極板１０３は、負極側集電部を介して、同じく金属箔製の負極端子１０５に接続されている。なお、本例の正極側集電部及び正極端子１０４並びに負極側集電部及び負極端子１０５のそれぞれは、同じ一枚の金属箔から構成されている。
【００１６】
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、銅またはステンレスなどを挙げることができる。また、本例の正極側集電部も負極側集電部の何れも、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を構成することもできる。
【００１７】
発電要素１０９は、上部電池外装１０６及び下部電池外装１０７により封止されている。これら上部電池外装１０６および下部電池外装１０７は、例えばポリエチレンやポリプロピレンなどの樹脂フィルムや、アルミニウムなどの金属箔の両面をポリエチレンやポリプロピレンなどの樹脂でラミネートした、樹脂−金属薄膜ラミネート材など、柔軟性を有する材料で形成されている。特に、電池外装１０６，１０７の内面を構成する樹脂フィルムを、電解質に対する耐薬品性に優れ、外周縁のヒートシール性にも優れた、たとえばポリエチレン、ポリプロピレン、アイオノマー樹脂等により構成するとともに、中間にたとえばアルミニウム箔やステンレス箔などの可撓性及び強度に優れた金属箔を介在させ、電池外装１０６，１０７の外面を構成する樹脂フィルムを、電気絶縁性に優れたたとえばポリアミド系樹脂、ポリエステル系樹脂等で構成することができる。
【００１８】
そして、これらの上部電池外装１０６及び下部電池外装１０７によって、上述した発電要素１０９、正極側集電部、正極端子１０４の一部、負極側集電部および負極端子１０５の一部を包み込み、当該電池外装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１０２を注入したのち、上部電池外装１０６及び下部電池外装１０７の外周縁を熱融着などの方法により封止する。
【００１９】
電解質を構成する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。
【００２０】
特に本例の上部電池外装１０６及び下部電池外装１０７には、図４に示すように切欠部１０６Ａ，１０７Ａと導通部１０６Ｂ，１０７Ｂとがそれぞれ形成されている。この構造について図１〜図３及び図５を参照しながら詳細に説明する。
【００２１】
図１は下部電池外装１０７を分解して示したもの、図２は下部電池外装１０７に設けられる電圧検出線２０の構造を示したもの、図３は下部電池外装１０７に形成された切欠部１０７Ａと電圧検出線２０の接続端部２０１との接続構造を示したもの、図５は下部電池外装１０７の導電部１０７Ｂと負極板１０２との位置関係を示したものである。
【００２２】
図１に示すように、下部電池外装１０７は、アルミニウムなどの金属箔１０７１を樹脂フィルム１０７２，１０７３により挟んで構成されているが、さらに本例では、電池外装１０７の内面を構成する樹脂フィルム１０７２の中央部がくり抜かれ、このくり抜かれた開口部には導電性接着剤などの導電性材料１０７４が充填されて穴埋めされている（穴埋めされた状態を導電部１０７Ｂと称する）。そして、薄型電池１０を組み立てると、図５に示すように導電性接着剤１０７４により穴埋めされた導電部１０７Ｂが負極板１０３に接触することになる。
【００２３】
また、図１に示すように、下部電池外装１０７の内側を構成する樹脂フィルム１０７２の一端縁が切り欠かれて切欠部１０７Ａが形成され、ここに電圧検出線２０の接続端部２０１が接続されている。
【００２４】
電圧検出線２０は、図２に示すように芯線２０２を絶縁性被覆材２０３にて被覆したもので、その先端部は絶縁性被覆材２０３が除去されて芯線２０２が露出している。本例では、露出した芯線２０２の部分を２枚の金属板２０４，２０４で挟み、この状態で切欠部１０７Ａに取り付けられている。なお、芯線２０２を挟む金属板２０４は、図２に示すように芯線２０２を挟む部分のみを芯線２０２の形状に応じて成形しておき、その他の部分を平坦形状としておく。
【００２５】
また、芯線２０２を挟んだ金属板２０４，２０４は、図３に示すように切欠部１０７Ａにおいて露出した金属箔１０７１に電気的に接触するように装着され、樹脂などの材料により被覆されている。
【００２６】
上述した導電部１０７Ｂにより負極板１０３と下部電池外装１０７の金属箔１０７２とは電気的に接続され、さらに切欠部１０７Ａにより下部電池外装１０７の金属箔１０７２と電圧検出線２０も電気的に接続されるので、負極板１０３は電圧検出線２０に電気的に接続されることになる。
【００２７】
図１〜図３に示す例は、下部電池外装１０７に電圧検出線２０を装着したものであるが、薄型電池１０全体としては、上部電池外装１０６についても下部電池外装１０７と同様に構成されている（図７参照）。
【００２８】
すなわち、上部電池外装１０６の内面を構成する樹脂フィルム１０６２の中央部がくり抜かれ、このくり抜かれた開口部には導電性接着剤などの導電性材料１０６４が充填されて穴埋めされている（穴埋めされた状態を導電部１０６Ｂと称し、図４に示す）。そして、薄型電池１０を組み立てると、導電性接着剤１０６４により穴埋めされた導電部１０６Ｂが正極板１０１に接触することになる。
【００２９】
また、上部電池外装１０６の内側を構成する樹脂フィルム１０６２の一端縁が切り欠かれて切欠部１０６Ａが形成され、ここに電圧検出線２１の接続端部２１１が接続されている。なお、電圧検出線２１の接続端部２１１は、下部電池外装１０７の場合と同じように図２に示す構造とされている。
【００３０】
上部電池外装１０６の導電部１０６Ｂにより正極板１０１と上部電池外装１０６の金属箔１０６１とが電気的に接続され、さらに切欠部１０６Ａにより上部電池外装１０６の金属箔１０６１と電圧検出線２１も電気的に接続されるので、正極板１０１は電圧検出線２１に電気的に接続されることになる。
【００３１】
本例では特に、上部電池外装１０６の電圧検出線２１と、下部電池外装１０７の電圧検出線２０とを、電池外装の同じ辺に設けている。こうすることで、上部電池外装１０６と下部電池外装１０７とが同じ形状となり、部品の共用化を図ることができるとともに、電圧検出線２０，２１の引き出し位置が近くなるので、電圧検出線２０，２１の他方の接続部品であるセルコントローラ（不図示）までの距離を最短にすることができる。
【００３２】
なお、２本の電圧検出線２０，２１はセルコントローラにて電圧計に接続され、これにより、発電要素１０９の正極板１０１及び負極板１０２の間の電圧を検出することができる。
【００３３】
次に本例の薄型電池１０の組立方法について図７及び図８を参照しながら説明する。図７は組立前の状態を示す分解断面図、図８は組立後の状態を示す断面図であり、同図（Ａ）は電極端子１０４，１０５の部分の断面図、同図（Ｂ）は電圧検出線２０，２１の部分断面図である。
【００３４】
まず、上部電池外装１０６及び下部電池外装１０７を所定の大きさに形成し、また切欠部１０６Ａ，１０６Ｂ及び導電部１０６Ｂ，１０７Ｂを形成したのち、切欠部１０６Ａ，１０７Ｂのそれぞれに電圧検出線２０，２１を取り付ける。
【００３５】
この上部電池外装１０６及び下部電池外装１０７の間に、図７に示すように正極端子１０４を有する正極板１０１と負極端子１０５を有する負極板１０３とを配置した状態で、重ね合わされた上部電池外装１０６と下部電池外装１０７の外周縁を熱融着などの方法により封止する。この熱シールの工程では、電池外装１０６，１０７の外周縁をシールすると同時に、２本の電圧検出線２０，２１の挟持シールも行うことができるので、別途電圧検出線を固定する工程が不要となる。
【００３６】
また、電圧検出線２０，２１の接続端部２０１，２１１は、上部電池外装１０６及び下部電池外装１０７のそれぞれに形成された切欠部１０６Ａ，１０７Ａに面一に設けられているので、図８（Ｂ）に示すように、この電圧検出線２０，２１を挟んだ状態で電池外装１０６，１０７の外周縁を熱シールした場合でも、外周縁に段差が殆ど発生せず、気密性・水密性が確保される。
【００３７】
最後に、熱シールした電池外装１０６，１０７の外周縁の一部を剥がし、ここから電解質を注入し、再度熱シールすることで薄型電池１０が完成する。
【００３８】
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。
【図面の簡単な説明】
【図１】本発明の実施形態に係る電池外装の一方を示す分解斜視図である。
【図２】本発明の実施形態に係る電圧検出線の接続端部を示す分解斜視図である。
【図３】本発明の実施形態に係る電圧検出線の接続端部と電池外装との接続構造を示す断面図である。
【図４】本発明の実施形態に係る薄型電池を示す分解斜視図である。
【図５】本発明の実施形態に係る電池外装と電極との接続部分（導電部）を示す断面図である。
【図６】本発明の実施形態に係る薄型電池を示す斜視図である。
【図７】本発明の実施形態に係る薄型電池を示す分解断面図である。
【図８】本発明の実施形態に係る薄型電池を示す断面図である。
【符号の説明】
１０…薄型電池
１０１…正極板
１０２…電解質
１０３…負極板
１０４…正極端子
１０５…負極端子
１０６…上部電池外装
１０６Ａ…切欠部
１０６Ｂ…導電部
１０７…下部電池外装
１０７Ａ…切欠部
１０７Ｂ…導電部
１０９…発電要素
２０，２１…電圧検出線
２０１，２１１…接続端部
２０４…金属板[0001]
【Technical field】
The present invention relates to a thin secondary battery in which a power generation element is accommodated in a battery exterior and has an electrode terminal and a voltage detection line.
[0002]
[Background]
Since the thin battery is small and light, it is possible to increase the voltage and capacity by connecting a plurality of the thin batteries into an assembled battery (see, for example, Patent Document 1). Such an assembled battery is provided with a voltage detection line for detecting the voltage of each thin battery, and further provided with a battery control board (cell controller) for monitoring and controlling the assembled battery.
[0003]
By the way, the conventional voltage detection line is electrically connected to the electrode terminal or the external terminal connected thereto using a screw or the like. For this reason, there is a problem in that a separate process for connecting the voltage detection line to the electrode terminal or the like is required, and the manufacturing process becomes much longer.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 9-259859
DISCLOSURE OF THE INVENTION
An object of this invention is to provide the thin battery which can simplify the manufacturing process of a voltage detection line.
[0006]
In order to achieve the above object, according to the present invention, a pair of battery exteriors in which an insulating film is laminated on both main surfaces of a conductive film, and an outer peripheral edge of the pair of battery exteriors are sealed inside. In a thin battery having a housed power generation element and an electrode terminal connected to an electrode of the power generation element and led out from an outer peripheral edge of the battery exterior, the conductive film on the battery exterior is partially connected to the electrode There is provided a thin battery having a conduction part to be connected and a voltage detection line that is electrically connected to the electrode through the conduction part and the conductive film and detects a voltage of the electrode.
[0007]
In the present invention, a voltage detection line is connected to an electrode, which is a voltage detection target, through a conductive film using a conductive film on the battery exterior. Since the connection edge part of a voltage detection line is pinched | interposed by the said peripheral part when sealing the peripheral part of a pair of battery exterior, a voltage detection line can be connected in a sealing process.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an exploded perspective view showing one of battery exteriors (lower battery exterior 107) according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view showing a connection end of a voltage detection line according to an embodiment of the present invention. 3 is a cross-sectional view showing a connection structure between a connection end portion of a voltage detection line and a cutout portion of a battery exterior according to an embodiment of the present invention, and FIG. 4 is an exploded perspective view showing a thin battery according to the embodiment of the present invention. 5 is a cross-sectional view showing a connection portion (conductive portion) between the battery exterior and the electrode according to the embodiment of the present invention, FIG. 6 is a perspective view showing a completed state of the thin battery according to the embodiment of the present invention, and FIG. FIG. 8 is a sectional view showing a thin battery according to an embodiment of the present invention. FIG.
[0009]
The overall configuration of the thin battery of this embodiment will be described with reference to FIGS. 4 and 6 to 8. The thin battery 10 of this example is a lithium-based thin secondary battery, and includes one positive electrode plate 101, An electrolyte 102, a single negative electrode plate 103, a positive electrode terminal 104, a negative electrode terminal 105, an upper battery exterior 106, and a lower battery exterior 107 are configured. Among these, the positive electrode plate 101, the electrolyte 102, the negative electrode plate 103, and the power generation element 109 are particularly referred to.
[0010]
Note that the number of the positive electrode plate 101, the electrolyte 102, and the negative electrode plate 103 is not limited at all, and the power generation element 109 can be configured by a plurality of positive electrode plates 101 and negative electrode plates 104 as necessary.
[0011]
The positive electrode plate 101 constituting the power generation element 109 has 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 is applied to both surfaces of a metal foil such as an aluminum foil as a positive electrode side current collector, dried, rolled, and then cut into a predetermined size. In addition, the mixing ratio of said aqueous dispersion of polytetrafluoroethylene is the solid content.
[0012]
Examples of the positive electrode active material include lithium composite oxides such as lithium nickelate (LiNiO ₂ ), lithium manganate (LiMnO ₂ ), lithium cobaltate (LiCoO ₂ ), and chalcogen (S, Se, Te) compounds. Can do.
[0013]
The negative electrode plate 103 constituting the power generation element 109 is made of a negative electrode active material that occludes and releases lithium ions of the positive electrode active material, such as amorphous carbon, non-graphitizable carbon, graphitizable carbon, or graphite. An aqueous dispersion of styrene butadiene rubber resin powder as a precursor material of an organic fired body is mixed at a solid content ratio of, for example, 100: 5, dried and then pulverized to support carbonized styrene butadiene rubber on the surface of carbon particles The resulting material is mixed with a binder such as an acrylic resin emulsion at a weight ratio of, for example, 100: 5, and this mixture is used as a metal foil such as nickel foil or copper foil as a negative electrode side current collector. These are coated on both sides, dried, rolled, and then cut into a predetermined size.
[0014]
In particular, when amorphous carbon or non-graphitizable carbon is used as the negative electrode active material, the flatness of the potential during charge / discharge is poor and the output voltage decreases with the amount of discharge. However, when used as a power source for an electric vehicle or the like, it is advantageous because there is no sudden drop in output.
[0015]
The positive electrode plate 101 is connected to the positive electrode terminal 104 made of metal foil via a positive electrode side current collector, while the negative electrode plate 103 is connected to the negative electrode terminal 105 also made of metal foil via a negative electrode side current collector. It is connected to the. Note that each of the positive electrode side current collector and positive electrode terminal 104 and the negative electrode side current collector and negative electrode terminal 105 of the present example is composed of the same single metal foil.
[0016]
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 and an aluminum alloy, and examples of the negative electrode terminal 105 include nickel, copper, and stainless steel. And so on. In addition, both the positive electrode side current collector and the negative electrode side current collector of this example are configured by extending the aluminum foil, nickel foil, and copper foil constituting the current collector of the positive electrode plate 104 and the negative electrode plate 105. However, the said current collection part can also be comprised with a separate material and components.
[0017]
The power generation element 109 is sealed by the upper battery casing 106 and the lower battery casing 107. The upper battery casing 106 and the lower battery casing 107 are flexible, such as a resin film of polyethylene or polypropylene, a resin-metal thin film laminate material in which both surfaces of a metal foil such as aluminum are laminated with a resin such as polyethylene or polypropylene, and the like. It is formed with the material which has. In particular, the resin film constituting the inner surfaces of the battery outer casings 106 and 107 is made of, for example, polyethylene, polypropylene, ionomer resin, etc. having excellent chemical resistance to the electrolyte and excellent heat sealability of the outer periphery, and in the middle. For example, a resin film constituting the outer surface of the battery exterior 106, 107 is interposed between a metal foil excellent in flexibility and strength, such as aluminum foil and stainless steel foil, for example, a polyamide resin or a polyester resin excellent in electrical insulation. Or the like.
[0018]
The upper battery casing 106 and the lower battery casing 107 enclose the power generation element 109, the positive electrode current collector, a part of the positive electrode terminal 104, the negative electrode current collector and a part of the negative electrode terminal 105, and After injecting a liquid electrolyte 102 having a lithium salt such as lithium perchlorate or lithium borofluoride into an organic liquid solvent into the space formed by the battery casings 106 and 107, the upper battery casing 106 and the lower battery casing 107 The outer peripheral edge is sealed by a method such as heat sealing.
[0019]
Examples of the organic liquid solvent constituting the electrolyte 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 limited to this. In addition, an organic liquid solvent prepared by mixing and preparing an ether solvent such as γ-butylactone (γ-BL) or dietoshietane (DEE) in an ester solvent can be used.
[0020]
In particular, as shown in FIG. 4, notches 106A and 107A and conduction portions 106B and 107B are formed in the upper battery casing 106 and the lower battery casing 107 of this example, respectively. This structure will be described in detail with reference to FIGS. 1 to 3 and FIG.
[0021]
1 shows an exploded view of the lower battery casing 107, FIG. 2 shows the structure of the voltage detection line 20 provided in the lower battery casing 107, and FIG. 3 shows a notch 107A formed in the lower battery casing 107. FIG. 5 shows the positional relationship between the conductive portion 107B of the lower battery exterior 107 and the negative electrode plate 102. FIG.
[0022]
As shown in FIG. 1, the lower battery casing 107 is configured by sandwiching a metal foil 1071 such as aluminum between resin films 1072 and 1073. In this example, however, the resin film 1072 constituting the inner surface of the battery casing 107 is used. The hollowed portion is filled with a conductive material 1074 such as a conductive adhesive and is filled with a hole (the filled state is referred to as a conductive portion 107B). When the thin battery 10 is assembled, as shown in FIG. 5, the conductive portion 107 </ b> B filled with the conductive adhesive 1074 comes into contact with the negative electrode plate 103.
[0023]
Further, as shown in FIG. 1, one end edge of the resin film 1072 constituting the inside of the lower battery exterior 107 is notched to form a notch 107A, and the connection end 201 of the voltage detection line 20 is connected thereto. ing.
[0024]
As shown in FIG. 2, the voltage detection line 20 is obtained by coating the core wire 202 with an insulating coating material 203, and the insulating coating material 203 is removed at the tip of the core wire 202 to expose it. In this example, the exposed portion of the core wire 202 is sandwiched between two metal plates 204 and 204 and attached to the notch 107A in this state. In addition, as shown in FIG. 2, only the part which pinches the core wire 202 shape | molds the metal plate 204 which pinches | interposes the core wire 202 according to the shape of the core wire 202, and makes other parts flat shape.
[0025]
Further, as shown in FIG. 3, the metal plates 204 and 204 sandwiching the core wire 202 are mounted so as to be in electrical contact with the metal foil 1071 exposed at the notch 107A, and are covered with a material such as a resin.
[0026]
The negative electrode plate 103 and the metal foil 1072 of the lower battery casing 107 are electrically connected by the conductive portion 107B described above, and the metal foil 1072 of the lower battery casing 107 and the voltage detection line 20 are also electrically connected by the notch 107A. Therefore, the negative electrode plate 103 is electrically connected to the voltage detection line 20.
[0027]
In the example shown in FIGS. 1 to 3, the voltage detection line 20 is attached to the lower battery casing 107, but the thin battery 10 as a whole is configured similarly to the lower battery casing 107 for the upper battery casing 106. (See FIG. 7).
[0028]
That is, the central portion of the resin film 1062 constituting the inner surface of the upper battery exterior 106 is hollowed out, and the hollowed opening is filled with a conductive material 1064 such as a conductive adhesive (filled). This state is referred to as a conductive portion 106B and is shown in FIG. When the thin battery 10 is assembled, the conductive portion 106B filled with the conductive adhesive 1064 comes into contact with the positive electrode plate 101.
[0029]
Further, one end edge of the resin film 1062 constituting the inside of the upper battery exterior 106 is notched to form a notch portion 106A, to which the connection end portion 211 of the voltage detection line 21 is connected. Note that the connection end 211 of the voltage detection line 21 has the structure shown in FIG.
[0030]
The positive electrode plate 101 and the metal foil 1061 of the upper battery casing 106 are electrically connected by the conductive portion 106B of the upper battery casing 106, and the metal foil 1061 and the voltage detection line 21 of the upper battery casing 106 are also electrically connected by the notch 106A. Therefore, the positive electrode plate 101 is electrically connected to the voltage detection line 21.
[0031]
Particularly in this example, the voltage detection line 21 of the upper battery exterior 106 and the voltage detection line 20 of the lower battery exterior 107 are provided on the same side of the battery exterior. By doing so, the upper battery outer casing 106 and the lower battery outer casing 107 have the same shape, so that parts can be shared and the lead-out positions of the voltage detection lines 20 and 21 are close. The distance to the cell controller (not shown) which is the other connecting component of 21 can be minimized.
[0032]
Note that the two voltage detection lines 20 and 21 are connected to a voltmeter by a cell controller, whereby the voltage between the positive electrode plate 101 and the negative electrode plate 102 of the power generation element 109 can be detected.
[0033]
Next, a method for assembling the thin battery 10 of this example will be described with reference to FIGS. 7 is an exploded sectional view showing a state before assembly, FIG. 8 is a sectional view showing a state after assembly, FIG. 7A is a sectional view of the electrode terminals 104 and 105, and FIG. 3 is a partial cross-sectional view of voltage detection lines 20 and 21. FIG.
[0034]
First, after the upper battery casing 106 and the lower battery casing 107 are formed in a predetermined size, and the notches 106A and 106B and the conductive parts 106B and 107B are formed, the voltage detection lines 20, 21 is attached.
[0035]
Between the upper battery casing 106 and the lower battery casing 107, as shown in FIG. 7, the upper battery casing overlapped with the positive electrode plate 101 having the positive electrode terminal 104 and the negative electrode plate 103 having the negative electrode terminal 105 arranged. 106 and the outer peripheral edge of the lower battery exterior 107 are sealed by a method such as heat sealing. In this heat sealing step, the outer peripheral edges of the battery sheaths 106 and 107 can be sealed and at the same time the two voltage detection lines 20 and 21 can be sandwiched and sealed, so that there is no need to separately fix the voltage detection lines. Become.
[0036]
Further, since the connection ends 201 and 211 of the voltage detection lines 20 and 21 are provided flush with the notches 106A and 107A formed in the upper battery exterior 106 and the lower battery exterior 107, respectively. As shown in B), even when the outer peripheral edges of the battery sheaths 106 and 107 are heat-sealed with the voltage detection lines 20 and 21 sandwiched therebetween, almost no step is generated on the outer peripheral edges, and airtightness and watertightness are achieved. Secured.
[0037]
Finally, a part of the outer peripheral edge of the heat-sealed battery sheaths 106 and 107 is peeled off, an electrolyte is injected from this, and the thin battery 10 is completed by heat-sealing again.
[0038]
The embodiment described above is described for facilitating the understanding of the present invention, and is 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.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing one side of a battery exterior according to an embodiment of the present invention.
FIG. 2 is an exploded perspective view showing a connection end portion of a voltage detection line according to an embodiment of the present invention.
FIG. 3 is a cross-sectional view showing a connection structure between a connection end portion of a voltage detection line and a battery exterior according to an embodiment of the present invention.
FIG. 4 is an exploded perspective view showing a thin battery according to an embodiment of the present invention.
FIG. 5 is a cross-sectional view showing a connection portion (conductive portion) between a battery exterior and an electrode according to an embodiment of the present invention.
FIG. 6 is a perspective view showing a thin battery according to an embodiment of the present invention.
FIG. 7 is an exploded cross-sectional view showing a thin battery according to an embodiment of the present invention.
FIG. 8 is a cross-sectional view showing a thin battery according to an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Thin battery 101 ... Positive electrode plate 102 ... Electrolyte 103 ... Negative electrode plate 104 ... Positive electrode terminal 105 ... Negative electrode terminal 106 ... Upper battery exterior 106A ... Notch part 106B ... Conductive part 107 ... Lower battery exterior 107A ... Notch part 107B ... Conductive part 109 ... Power generation elements 20, 21 ... Voltage detection lines 201, 211 ... Connection end 204 ... Metal plate

Claims

A pair of battery exteriors in which insulating films are laminated on both main surfaces of the conductive film, a power generation element housed inside by sealing the outer periphery of the pair of battery exteriors, and connected to electrodes of the power generation element In the thin battery having an electrode terminal derived from the outer periphery of the battery exterior,
A conductive part for conducting the conductive film on the battery exterior and the electrode; and a voltage detection line that is electrically connected to the electrode via the conductive part and the conductive film to detect the voltage of the electrode; A thin battery having:

The connection end of the voltage detection line is electrically connected to the conductive film of one battery exterior of the pair of battery exteriors, and the connection end of the voltage detection line and one of the one battery exterior notch in the end of the insulating film so that an insulating film becomes substantially flush is formed,
The thin battery according to claim 1, wherein a conductive portion conducting to the conductive film and the one electrode of the one battery exterior is formed in a part of the one insulating film of the one battery exterior.

The connection end of another voltage detection line different from the voltage detection line is electrically connected to the conductive film of the other battery exterior, and the connection end of the other voltage detection line and the other battery exterior notch in the end of the insulating film so that one and the insulating film is substantially flush is formed,
The thin battery according to claim 2, wherein a conductive portion conducting to the conductive film and the other electrode of the other battery exterior is formed in a part of the one insulating film of the other battery exterior.

The thin battery according to claim 3, wherein the two notches are provided at the same end of the battery exterior.

5. The thin battery according to claim 1, wherein the connection end portion of the voltage detection line is configured by sandwiching a core wire of the voltage detection line between two metal plates.

The said conduction | electrical_connection part is comprised by the opening part formed in the insulating film which faces the said electrode of the said battery exterior, and the filling member which consists of an electroconductive material with which the said opening part was filled. A thin battery according to any one of the above.