JP3648152B2

JP3648152B2 - Storage element and method for manufacturing the same

Info

Publication number: JP3648152B2
Application number: JP2000367059A
Authority: JP
Inventors: 裕二中川; 利彦西山; 浩幸紙透; 学原田; 雅人黒崎; 真也吉田; 知希信田; 豊中澤; 勝哉三谷
Original assignee: NEC Tokin Corp
Current assignee: Tokin Corp
Priority date: 2000-12-01
Filing date: 2000-12-01
Publication date: 2005-05-18
Anticipated expiration: 2020-12-01
Also published as: JP2002170552A

Description

【０００１】
【発明の属する技術分野】
本発明は、蓄電素子及びその製造方法に関し、特に、二次電池や電気二重層コンデンサ等の電気的な短絡を防止すると共に、素子の小型化を可能とした蓄電素子及びその製造方法に関するものである。
【０００２】
【従来の技術】
近年、情報通信の分野では、携帯機器の小型化・軽量化が進んでおり、これに対応すべく二次電池や電気二重層コンデンサの開発が盛んに行われている。例えば、二次電池の場合、小型軽量化実現のために、形態自由度の高い柔軟な電池もしくは薄型大面積のシート電池、薄型小面積のカード型電池が望まれている。
そこで、これら二次電池や電気二重層コンデンサにおいては、外装材に、高分子膜や金属箔を貼り合わせてなる複数層から構成されるラミネートフィルムを用いたものが提案されている。
【０００３】
しかしながら、これらの二次電池や電気二重層コンデンサにおいては、基本セルを複数個積層し、ラミネート容器を用いて外装しているために、外装する時に電気的な短絡が発生するという問題がある。これは、積層したセルの側面部の集電体と端子板が接触することが原因として挙げられる。その理由は、集電体が基本セルを積層した積層セルの側面に露出し、また、端子板が外装パッケージを貫通して外方に露出しているために、外装時にこの集電体と端子板が接触し短絡が発生するからである。
【０００４】
この積層セル側面の集電体と端子板との短絡を防ぐ方法として、従来から幾つかの方法が提案されている。
例えば、特開平４−２３７１０９号公報には、基本セルを複数積層した電気二重層コンデンサ及びその製造方法が開示されている（以下、従来例１と称する）。
図３は、この電気二重層コンデンサを示す断面図であり、積層セル１１を陽極端子１２、陰極端子１３および絶縁ケース１４と共に外装ケース１５に組み込み、その後、外装ケース１５をかしめることにより製造される。
この電気二重層コンデンサでは、積層セル１１と陰極端子１３の間に絶縁ケース１４があるために、両者間の短絡を防止することができる。
【０００５】
また、特開平８−７８２９１号公報には、隣接する２つのセルの間に１枚の集電体を備え、この集電体の外周部が隣接するガスケット間に挟み込まれて固着されている構造の電気二重層コンデンサが開示されている（以下、従来例２と称する）。
図４は、この電気二重層コンデンサを示す断面図であり、図において、２１は円板状の集電体、２２は円板状のセパレータ、２３はセパレータ２２と略同径の円板状の集電体、２４は平リング状で非導電性のゴム材からなるガスケット、２５は活性炭電極である。
ここで、活性炭電極２５は粉末あるいは固体の活性炭に電解液を含浸させたものである。
【０００６】
この電気二重層コンデンサは次のようにして製造される。
まず、ガスケット２４と、直径がガスケット２４の外径に等しい円板状の集電体２１と、直径がガスケット２４の外径と内径の中間値をとる円板状のセパレータ２２と、同様に直径がガスケット２４の外径と内径の中間値をとる円板状の集電体２３を準備する。
次いで、ガスケット２４の片面に集電体２１を貼り合せ、活性炭電極２５を詰めた器Ａと、ガスケット２４の片面にセパレータ２２を同心円状に貼り合せ、活性炭電極２５を詰めた器Ｂと、ガスケット２４の片面に集電体２３を同心円状に貼り合せ、活性炭電極２５を詰めた器Ｃを、それぞれ複数個作製し、器Ａを下段にして器Ｂを積層して合体させる。なお、各器Ａ〜Ｃには同量の活性炭電極２５が詰め込まれており、各器Ａ〜Ｃはそれぞれがセル1個分に相当している。
【０００７】
次いで、器Ａ及び器Ｂの組を最下段にし、その上に器Ｃ、器Ｂを交互に重ねて貼り合せた後、最上段の器Ｂの上に集電体２１を貼り合せ、次いで、ガスケット２４のゴム材の加硫特性を利用して電解液を封止する。以上により、電気二重層コンデンサが完成する。
この電気二重層コンデンサでは、隣接する２つのセルの間に１枚の集電体２３を挟み込み、この集電体２３の外周部をガスケット２４の外側の外周部より小さくして該ガスケット２４の内側に収納することで、集電体２３と端子板間を絶縁しており、且つ厚み方向の小型化を実現している。
【０００８】
【発明が解決しようとする課題】
ところで、従来例１の電気二重層コンデンサにおいては、絶縁ケース１４及び外装ケース１５を使用しているため、製品の外径が大きくなってしまい、さらなる小型化が難しいという問題点があった。
また、従来例２の電気二重層コンデンサにおいては、製造する際に、ガスケット２４の径方向の厚みは、集電体２３及びセパレータ２２を貼り合せるのに十分な厚み、例えば、最低１ｍｍの厚みを確保しなければならず、ガスケット２４と集電体２３及びセパレータ２２の固着部分を小さくすることが難しく、電気二重層コンデンサの径方向の小型化が困難であるという問題点があった。
【０００９】
また、これらの電気二重層コンデンサを小型、省スペースの電子機器に用いる場合、その外形形状は体積効率を考えると四角形状がよいのであるが、四角形状の場合、ガスケット２４と集電体２３及びセパレータ２２との固着部分を小さくしようとすると、位置合わせがさらに困難になるという問題点があった。
【００１０】
本発明は、上記の事情に鑑みてなされたものであって、積層セル側面の集電体と端子板との電気的な短絡を防止することができ、かつ、小型化が実現可能な蓄電素子及びその製造方法を提供することを目的とする。
【００１１】
【課題を解決するための手段】
上記課題を解決するために、本発明は次のような蓄電素子及びその製造方法を採用した。
すなわち、請求項１記載の蓄電素子は、複数の基本セル及び集電体を交互に積層してなる積層セルと、該積層セルの両端にそれぞれ設けられ電気的に接続される端子とを備え、前記基本セルは、一対の電極が分離層を介して対向配置され、これら積層セル及び端子は外装パッケージにより覆われてなる蓄電素子であって、
前記積層セルの側面部の集電体と一方の前記端子との接触部に絶縁層を設け、この一方の端子の前記絶縁層側の端部は、前記積層セルの側面から外方に垂直に延び、前記外装パッケージを貫通して外方に露出していることを特徴とする。
【００１２】
請求項２記載の蓄電素子は、請求項１記載の蓄電素子において、前記基本セルは、正電極及び負電極が分離層を介して対向配置された二次電池用基本セルであることを特徴とする。
【００１３】
請求項３記載の蓄電素子は、請求項１記載の蓄電素子において、前記基本セルは、一対の分極性電極が分離層を介して対向配置された電気二重層コンデンサ用基本セルであることを特徴とする。
【００１４】
請求項４記載の蓄電素子は、請求項１、２または３記載の蓄電素子において、前記絶縁層は、絶縁性の有機樹脂であることを特徴とする。
【００１５】
請求項５記載の蓄電素子は、請求項４記載の蓄電素子において、前記有機樹脂は、熱硬化型樹脂、紫外線硬化型樹脂、有機樹脂フィルムのいずれかであることを特徴とする。
【００１６】
請求項６記載の蓄電素子の製造方法は、複数の基本セル及び集電体を交互に積層してなる積層セルと、該積層セルの両端にそれぞれ設けられ電気的に接続される端子とを備え、前記基本セルは、一対の電極が分離層を介して対向配置され、これら積層セル及び端子は、一方の端子の端部が外方に露出している状態で外装パッケージにより覆われてなる蓄電素子の製造方法であって、
一方の前記端子の端部が前記積層セルの側面部から外方に垂直に延びている状態で、前記積層セルの両端に、それぞれ前記端子を電気的に接続し、次いで、前記積層セルの側面部の集電体と一方の前記端子との接触部に絶縁性の有機樹脂を塗布し、該有機樹脂を硬化させることにより、前記積層セルの側面部の集電体と一方の前記端子との接触部に絶縁層を形成し、次いで、一方の前記端子の端部が外方に露出するように、これら全体を外装パッケージにより覆うことを特徴とする。
【００１７】
請求項７記載の蓄電素子の製造方法は、複数の基本セル及び集電体を交互に積層してなる積層セルと、該積層セルの両端にそれぞれ設けられ電気的に接続される端子とを備え、前記基本セルは、一対の電極が分離層を介して対向配置され、これら積層セル及び端子は、一方の端子の端部が外方に露出している状態で外装パッケージにより覆われてなる蓄電素子の製造方法であって、
一方の前記端子の端部が前記積層セルの側面部から外方に垂直に延びている状態で、前記積層セルの両端に、それぞれ前記端子を電気的に接続し、次いで、前記積層セルの側面部の集電体と一方の前記端子との接触部に絶縁性の有機樹脂を挟持し、該有機樹脂を熱融着させることにより、前記積層セルの側面部の集電体と一方の前記端子との接触部に絶縁層を形成し、次いで、一方の前記端子の端部が外方に露出するように、これら全体を外装パッケージにより覆うことを特徴とする。
【００１８】
【発明の実施の形態】
本発明の蓄電素子及びその製造方法の一実施の形態について図面に基づき説明する。
図１は、本発明の一実施の形態の二次電池の内部構造を示す断面図、図２は、この二次電池の基本セルの内部構造を示す断面図である。
この二次電池は、基本セル１を集電体２で挟んだ構造のセルを複数個積層してなる積層セル３の両端にはそれぞれ端子板４が電気的に接続され、この積層セル３の側面部の集電体２と端子板４との接触部には絶縁層５が設けられ、これら全体はラミネートからなる外装パッケージ６により覆われている。そして、一方の端子板４の端部は外装パッケージ６を貫通して外方に露出されている。
【００１９】
基本セル１の内部構造は、図２に示すように、負電極７と正電極８とが、微多孔性のセパレータ９を介して対向配置され、これらはガスケット１０内に挿入され、このガスケット１０の内部は、電解液が含浸された状態で、両端部それぞれに密着固定された集電体２により密封されている。
なお、負電極７及び正電極８を分極性電極に置き換えれば、電気二重層コンデンサとなる。
【００２０】
次に、本実施の形態の二次電池の製造方法について説明する。
まず、基本セル１を作製するために、ガスケット１０の一方の開口部に集電体２を密着固定し、このガスケット１０内に、負電極７と正電極８とを微多孔性のセパレータ９を介して対向配置したセルを正電極８が下側になった状態で挿入する。次いで、負電極７に集電体２を密着固定し、このセルに図示しない注入口から電解液を注入する。これにより、内部を電解液で含浸した基本セル１が得られる。
【００２１】
次いで、この基本セル１を２層以上積層した積層セル３の両端に、それぞれ端子板４を電気的に接続する。ここでは、正電極８側の端子板４の端部が積層セル３の側面から外方に垂直に延びている。次いで、側面部の集電体２と外方に垂直に延びる端子板４との接触部に絶縁層５を設け、この状態で、これら全体をラミネートを用いて外装し、外装パッケージ６により覆われた構造とする。
なお、負電極７及び正電極８を分極性電極に置き換えることにより、同様の製造工程により電気二重層コンデンサを作製することができる。
【００２２】
この二次電池では、積層セル３の側面部の集電体２と端子板４との接触部に絶縁層５を設けたことにより、集電体２と端子板４との間の接触による短絡が起こるおそれがない。また、従来のように絶縁ケースを使用する構造ではないから、積層セル３の面方向、すなわち径方向の大きさを小さくすることができ、素子の小型化が実現可能となる。
【００２３】
このように、本実施の形態の二次電池によれば、積層セル３の側面部の集電体２と端子板４との間の不注意な接触による短絡を防止することができる。したがって、この二次電池を長時間使用した場合においても短絡等の不具合が生じるおそれがなくなり、信頼性を向上させることができる。
【００２４】
また、積層セル３の側面部の集電体２と端子板４との接触部に絶縁層５を設けたので、全体をラミネートからなる外装パッケージ６により被覆することができ、従来のような絶縁ケースを使用する必要がない。したがって、構造を簡単化することができ、製造コストを低減することができる。また、積層セル３の面方向、すなわち径方向の大きさを小さくすることができるので、素子の小型化を図ることができる。
【００２５】
次に、本実施の形態の二次電池のより具体的な実施例及び比較例について説明する。
「実施例１」
電極材料として、負極活物質にＰＱｘ（ポリキノキサリン）、正極活物質にＰＣＩ（ポリシアノインドール）を用い、これらに導電材であるカーボン粉末を適量混合して加圧成型し、薄板状の負電極７及び正電極８を作製した。電解液としては４０ｗｔ％硫酸を用いた。次いで、成膜した電極７、８を微多孔性のセパレータ９を介して対向配置させ、集電体２、ガスケット１０を配置し、所定の圧力、時間、温度で加熱することにより、集電体２とガスケット１０との界面を加硫接着によって封止した。その後注入孔より上記電解液を注入した。
【００２６】
このようにして得られた基本セル１を２層以上積層して積層セル３とし、この積層セル３の両外端の集電体２、２にそれぞれ端子板４を所定位置に密着して配置し、積層セル３側面の集電体２と端子板４の接触部にエポキシ樹脂を塗布し、１２０℃で１時間、加硫接着し、その後ラミネートを用いて外装し、外装パッケージ６とした。
【００２７】
ここで、本実施例１の基本セル１を１０個積層した二次電池を１０００個作製し、短絡による不良発生率をしらべた。
その結果、本実施例１の二次電池では短絡による不良は０個であった。
【００２８】
「比較例」
積層セル３側面の集電体２と端子板４の間にエポキシを塗布しない他は、実施例１と同じ構成をもつ電池を作製した。
次いで、本比較例の基本セルを１０個積層した二次電池を１０００個作製し、短絡による不良発生率をしらべた。
その結果、本比較例の二次電池では短絡による不良は４１６個であった。
【００２９】
以上の結果より、本実施例１の二次電池は、比較例の二次電池と比べて短絡による不良が極めて少ない二次電池であることがわかる。その理由は、積層セル３側面の集電体２と端子板４の接触部にエポキシ樹脂を塗布・硬化させることにより絶縁体５を形成したので、短絡を防ぐことができたと考えられる。また、エポキシ樹脂を使用した場合、加硫接着時に硬化させることができ、硬化時間を短縮することができる。
【００３０】
「実施例２」
端子板４とガスケット１０との接触部にポリプロピレン（ＰＰ）を挟み、熱融着により双方を接着した他は、比較例と同じ構成を有する二次電池を作製した。次いで、本実施例２の基本セル１を１０個積層した二次電池を１０００個作製し、短絡による不良発生率をしらべた。
その結果、本実施例２の二次電池では短絡による不良は０個であった。
【００３１】
以上により、本実施例２の二次電池は、比較例の二次電池と比べて短絡による不良が極めて少ない二次電池であることがわかる。その理由は、端子板４とガスケット１０との接触部にポリプロピレン（ＰＰ）を挟み、熱融着により双方を接着させることにより絶縁体５を形成したので、短絡を防ぐことができたと考えられる。また、ポリプロピレン（ＰＰ）を使用した場合、その軟化温度は１８０℃であり、高温使用時による集電体２及び端子板４間の剥離が抑えられる。
【００３２】
「実施例３」
ガスケット１０と接触する端子板４の一部分に紫外線（ＵＶ）硬化型樹脂を塗布・硬化させた他は、比較例と同じ構成を有する二次電池を作製した。
次いで、本実施例３の基本セル１を１０個積層した二次電池を１０００個作製し、短絡による不良発生率をしらべた。
その結果、本実施例３の二次電池では短絡による不良は０個であった。
【００３３】
以上により、本実施例２の二次電池は、比較例の二次電池と比べて短絡による不良が極めて少ない二次電池であることがわかる。その理由は、ガスケット１０と接触する端子板４の一部分に紫外線（ＵＶ）硬化型樹脂を塗布・硬化させることにより絶縁体５を形成したので、集電体２−端子板４間の短絡を防ぐことができたと考えられる。
【００３４】
「実施例４」
電極材料に活性炭を用いた他は、実施例３と同じ構成を有する電気二重層コンデンサを作製した。
次いで、本実施例４の基本セル１を１０個積層した電気二重層コンデンサを１０００個作製し、短絡による不良発生率をしらべた。
その結果、本実施例４の電気二重層コンデンサでは短絡による不良は０個であった。
以上により、本実施例４の電気二重層コンデンサは、短絡による不良が極めて少ない電気二重層コンデンサであることが分かった。
【００３５】
以上の実施例１〜４及び比較例の短絡による不良発生率を表１にまとめた。
【表１】

【００３６】
以上、本発明の蓄電素子及びその製造方法の一実施の形態について図面に基づき説明してきたが、具体的な構成は本実施形態に限定されるものではなく、本発明の要旨を逸脱しない範囲で設計の変更等が可能である。
【００３７】
【発明の効果】
以上説明した様に、本発明の蓄電素子によれば、前記積層セルの側面部の集電体と一方の前記端子との接触部に絶縁層を設け、この一方の端子の前記絶縁層側の端部は、前記積層セルの側面から外方に垂直に延び、前記外装パッケージを貫通して外方に露出しているので、前記積層セルの側面部の集電体と前記端子との不注意な接触による短絡を防止することができる。したがって、この蓄電素子を長時間使用した場合においても短絡等の不具合が生じるおそれがなくなり、信頼性を向上させることができる。
【００３８】
また、従来のような絶縁ケースを使用する必要がないので、構造を簡単化することができ、製造コストを低減することができる。また、積層セルの面方向、すなわち径方向の大きさを小さくすることができるので、素子の小型化を図ることができる。
【００３９】
また、基本セルを、正電極及び負電極が分離層を介して対向配置された二次電池用基本セルとすれば、短絡等の不具合が生じるおそれがなく、信頼性が向上し、小型化及び製造コストの削減が可能な二次電池を提供することができる。
【００４０】
また、基本セルを、一対の分極性電極が分離層を介して対向配置された電気二重層コンデンサ用基本セルとすれば、短絡等の不具合が生じるおそれがなく、信頼性が向上し、小型化及び製造コストの削減が可能な電気二重層コンデンサを提供することができる。
【００４１】
本発明の蓄電素子の製造方法によれば、一方の前記端子の端部が前記積層セルの側面部から外方に垂直に延びている状態で、前記積層セルの両端に、それぞれ前記端子を電気的に接続し、次いで、前記積層セルの側面部の集電体と一方の前記端子との接触部に絶縁性の有機樹脂を塗布し、該有機樹脂を硬化させることにより、前記積層セルの側面部の集電体と一方の前記端子との接触部に絶縁層を形成し、次いで、一方の前記端子の端部が外方に露出するように、これら全体を外装パッケージにより覆うので、短絡等の不具合が生じるおそれがなく、信頼性が向上した蓄電素子を、高価な設備を用いることなく、簡単な工程で、しかも容易に作製することができる。
【００４２】
本発明の他の蓄電素子の製造方法によれば、一方の前記端子の端部が前記積層セルの側面部から外方に垂直に延びている状態で、前記積層セルの両端に、それぞれ前記端子を電気的に接続し、次いで、前記積層セルの側面部の集電体と一方の前記端子との接触部に絶縁性の有機樹脂を挟持し、該有機樹脂を熱融着させることにより、前記積層セルの側面部の集電体と一方の前記端子との接触部に絶縁層を形成し、次いで、一方の前記端子の端部が外方に露出するように、これら全体を外装パッケージにより覆うので、短絡等の不具合が生じるおそれがなく、信頼性が向上した蓄電素子を、高価な設備を用いることなく、簡単な工程で、しかも容易に作製することができる。
【図面の簡単な説明】
【図１】本発明の一実施の形態の二次電池の内部構造を示す断面図である。
【図２】本発明の一実施の形態の二次電池の基本セルの内部構造を示す断面図である。
【図３】従来の電気二重層コンデンサの一例を示す断面図である。
【図４】従来の電気二重層コンデンサの他の例を示す断面図である。
【符号の説明】
１基本セル
２集電体
３積層セル
４端子板
５絶縁層
６外装パッケージ
７負電極
８正電極
９微多孔性のセパレータ
１０ガスケット
１１積層セル
１２陽極端子
１３陰極端子
１４絶縁ケース
１５外装ケース
２１集電体
２２セパレータ
２３集電体
２４ガスケット
２５活性炭電極
Ａ〜Ｃ器[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a power storage device and a method for manufacturing the same, and more particularly to a power storage device capable of preventing electrical short-circuiting of a secondary battery, an electric double layer capacitor, and the like and miniaturizing the device, and a method for manufacturing the same. is there.
[0002]
[Prior art]
In recent years, in the field of information communication, portable devices have been reduced in size and weight, and secondary batteries and electric double layer capacitors have been actively developed to cope with this. For example, in the case of a secondary battery, a flexible battery with a high degree of freedom, a thin large-area sheet battery, and a thin small-area card type battery are desired in order to achieve a reduction in size and weight.
Thus, in these secondary batteries and electric double layer capacitors, those using a laminate film composed of a plurality of layers formed by bonding a polymer film or a metal foil to the exterior material have been proposed.
[0003]
However, these secondary batteries and electric double layer capacitors have a problem that an electrical short circuit occurs when they are packaged because a plurality of basic cells are stacked and packaged using a laminate container. This is because the current collector on the side surface portion of the stacked cells and the terminal plate are in contact with each other. The reason is that the current collector is exposed on the side surface of the stacked cell in which the basic cells are laminated, and the terminal plate is exposed to the outside through the exterior package. This is because the plates come into contact and a short circuit occurs.
[0004]
As a method for preventing a short circuit between the current collector on the side surface of the laminated cell and the terminal plate, several methods have been conventionally proposed.
For example, Japanese Patent Application Laid-Open No. 4-237109 discloses an electric double layer capacitor in which a plurality of basic cells are stacked and a manufacturing method thereof (hereinafter referred to as Conventional Example 1).
FIG. 3 is a cross-sectional view showing this electric double layer capacitor, which is manufactured by incorporating the laminated cell 11 into the outer case 15 together with the anode terminal 12, the cathode terminal 13 and the insulating case 14, and then caulking the outer case 15. The
In this electric double layer capacitor, since there is the insulating case 14 between the laminated cell 11 and the cathode terminal 13, it is possible to prevent a short circuit between them.
[0005]
Japanese Patent Laid-Open No. 8-78291 has a structure in which one current collector is provided between two adjacent cells, and the outer peripheral portion of the current collector is sandwiched and fixed between adjacent gaskets. An electric double layer capacitor is disclosed (hereinafter referred to as Conventional Example 2).
FIG. 4 is a cross-sectional view showing this electric double layer capacitor. In the figure, 21 is a disk-shaped current collector, 22 is a disk-shaped separator, and 23 is a disk-shaped disk having substantially the same diameter as the separator 22. A current collector, 24 is a flat ring-shaped gasket made of a non-conductive rubber material, and 25 is an activated carbon electrode.
Here, the activated carbon electrode 25 is obtained by impregnating powdered or solid activated carbon with an electrolytic solution.
[0006]
This electric double layer capacitor is manufactured as follows.
First, the gasket 24, the disk-shaped current collector 21 whose diameter is equal to the outer diameter of the gasket 24, the disk-shaped separator 22 whose diameter is an intermediate value between the outer diameter and the inner diameter of the gasket 24, and the diameter similarly. Prepares a disk-shaped current collector 23 having an intermediate value between the outer diameter and the inner diameter of the gasket 24.
Next, the collector A is bonded to one side of the gasket 24 and packed with the activated carbon electrode 25, and the separator B is bonded to one side of the gasket 24 concentrically and packed with the activated carbon electrode 25, and the gasket A current collector 23 is concentrically bonded to one side of 24, and a plurality of devices C each filled with activated carbon electrode 25 are produced, and device B is stacked on top of each other and united. Each of the devices A to C is packed with the same amount of the activated carbon electrode 25, and each of the devices A to C corresponds to one cell.
[0007]
Next, the set of the device A and the device B is placed at the bottom, and after the devices C and B are alternately stacked on top of each other, the current collector 21 is attached onto the device B at the top, The electrolyte solution is sealed using the vulcanization characteristics of the rubber material of the gasket 24. Thus, the electric double layer capacitor is completed.
In this electric double layer capacitor, one current collector 23 is sandwiched between two adjacent cells, and the outer peripheral portion of the current collector 23 is made smaller than the outer peripheral portion outside the gasket 24 so that the inner side of the gasket 24 is By being housed in, the current collector 23 and the terminal plate are insulated from each other, and downsizing in the thickness direction is realized.
[0008]
[Problems to be solved by the invention]
By the way, in the electric double layer capacitor of Conventional Example 1, since the insulating case 14 and the outer case 15 are used, the outer diameter of the product becomes large, and there is a problem that further miniaturization is difficult.
In addition, in the electric double layer capacitor of Conventional Example 2, when manufacturing, the thickness in the radial direction of the gasket 24 is sufficient to bond the current collector 23 and the separator 22, for example, a thickness of at least 1 mm. There is a problem that it is difficult to reduce the fixing portion of the gasket 24, the current collector 23, and the separator 22, and it is difficult to reduce the size of the electric double layer capacitor in the radial direction.
[0009]
In addition, when these electric double layer capacitors are used in a small-sized and space-saving electronic device, the outer shape is preferably a rectangular shape in view of volumetric efficiency, but in the case of a rectangular shape, the gasket 24 and the current collector 23 and If an attempt is made to reduce the fixing portion with the separator 22, there is a problem that alignment becomes more difficult.
[0010]
The present invention has been made in view of the above circumstances, and is an electric storage element that can prevent an electrical short circuit between a current collector on a side surface of a stacked cell and a terminal plate and can be miniaturized. And it aims at providing the manufacturing method.
[0011]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention employs the following electricity storage device and manufacturing method thereof.
That is, the electricity storage device according to claim 1 includes a stacked cell in which a plurality of basic cells and current collectors are alternately stacked, and terminals that are respectively provided and electrically connected to both ends of the stacked cell, The basic cell is a power storage element in which a pair of electrodes are arranged to face each other via a separation layer , and these stacked cells and terminals are covered with an exterior package,
An insulating layer is provided at a contact portion between the current collector on the side surface of the stacked cell and one of the terminals, and an end of the one terminal on the insulating layer side is perpendicular to the outside from the side of the stacked cell. It extends and is exposed to the outside through the exterior package .
[0012]
The electricity storage device according to claim 2 is the electricity storage device according to claim 1, wherein the basic cell is a basic cell for a secondary battery in which a positive electrode and a negative electrode are arranged to face each other via a separation layer. To do.
[0013]
The electricity storage device according to claim 3 is the electricity storage device according to claim 1, wherein the basic cell is a basic cell for an electric double layer capacitor in which a pair of polarizable electrodes are arranged to face each other via a separation layer. And
[0014]
A power storage device according to a fourth aspect is the power storage device according to the first, second, or third aspect, wherein the insulating layer is an insulating organic resin.
[0015]
The electricity storage device according to claim 5 is the electricity storage device according to claim 4, wherein the organic resin is any one of a thermosetting resin, an ultraviolet curable resin, and an organic resin film.
[0016]
The method for manufacturing a power storage device according to claim 6 includes a stacked cell in which a plurality of basic cells and current collectors are alternately stacked, and terminals that are provided at both ends of the stacked cell and are electrically connected to each other. In the basic cell, a pair of electrodes are arranged to face each other via a separation layer, and the stacked cell and the terminal are covered with an exterior package with the end of one terminal exposed to the outside. A method for manufacturing an element, comprising:
With the end of one of the terminals extending vertically outward from the side surface of the stacked cell, the terminals are electrically connected to both ends of the stacked cell, respectively, and then the side surface of the stacked cell An insulating organic resin is applied to a contact portion between the current collector of one part and one of the terminals, and the organic resin is cured, whereby the current collector on the side surface of the stacked cell and the one terminal An insulating layer is formed on the contact portion, and then the whole is covered with an exterior package so that an end portion of one of the terminals is exposed to the outside .
[0017]
The method for manufacturing a power storage device according to claim 7 includes a stacked cell in which a plurality of basic cells and current collectors are alternately stacked, and terminals that are respectively provided at both ends of the stacked cell and are electrically connected. In the basic cell, a pair of electrodes are arranged to face each other via a separation layer, and the stacked cell and the terminal are covered with an exterior package with the end of one terminal exposed to the outside. A method for manufacturing an element, comprising:
With the end of one of the terminals extending vertically outward from the side surface of the stacked cell, the terminals are electrically connected to both ends of the stacked cell, respectively, and then the side surface of the stacked cell An insulating organic resin is sandwiched between contact portions of the current collector and one of the terminals, and the organic resin is heat-sealed, whereby the current collector on the side surface of the stacked cell and the one terminal An insulating layer is formed at a contact portion with the outer package, and then, the whole is covered with an exterior package so that an end portion of one of the terminals is exposed to the outside .
[0018]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of a power storage device and a method for manufacturing the same according to the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view showing an internal structure of a secondary battery according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view showing an internal structure of a basic cell of the secondary battery.
In this secondary battery, terminal plates 4 are electrically connected to both ends of a laminated cell 3 in which a plurality of cells having a structure in which a basic cell 1 is sandwiched between current collectors 2 are laminated. An insulating layer 5 is provided at a contact portion between the current collector 2 and the terminal plate 4 on the side surface, and the whole is covered with an exterior package 6 made of a laminate. And the edge part of one terminal board 4 penetrates the exterior package 6, and is exposed outside.
[0019]
As shown in FIG. 2, the basic cell 1 has an internal structure in which a negative electrode 7 and a positive electrode 8 are arranged to face each other via a microporous separator 9, and these are inserted into a gasket 10. Is sealed with a current collector 2 which is in close contact with both ends in an impregnated state with an electrolytic solution.
If the negative electrode 7 and the positive electrode 8 are replaced with polarizable electrodes, an electric double layer capacitor is obtained.
[0020]
Next, a method for manufacturing the secondary battery of the present embodiment will be described.
First, in order to fabricate the basic cell 1, the current collector 2 is closely fixed to one opening of the gasket 10, and the negative electrode 7 and the positive electrode 8 are placed in the gasket 10 with a microporous separator 9. The cells arranged opposite to each other are inserted with the positive electrode 8 on the lower side. Next, the current collector 2 is tightly fixed to the negative electrode 7, and an electrolytic solution is injected into the cell from an injection port (not shown). Thereby, the basic cell 1 in which the inside is impregnated with the electrolytic solution is obtained.
[0021]
Next, terminal plates 4 are electrically connected to both ends of the laminated cell 3 in which two or more layers of the basic cell 1 are laminated. Here, the end of the terminal plate 4 on the positive electrode 8 side extends vertically outward from the side surface of the stacked cell 3. Next, an insulating layer 5 is provided at a contact portion between the current collector 2 on the side surface portion and the terminal plate 4 extending vertically outwardly. In this state, the whole is covered with a laminate and covered with the outer package 6. Structure.
In addition, by replacing the negative electrode 7 and the positive electrode 8 with polarizable electrodes, an electric double layer capacitor can be manufactured by the same manufacturing process.
[0022]
In this secondary battery, the insulating layer 5 is provided at the contact portion between the current collector 2 and the terminal plate 4 on the side surface portion of the stacked cell 3, thereby causing a short circuit due to contact between the current collector 2 and the terminal plate 4. There is no risk of occurrence. In addition, since the insulating case is not used as in the conventional case, the size of the stacked cell 3 in the surface direction, that is, the radial direction can be reduced, and the element can be downsized.
[0023]
Thus, according to the secondary battery of the present embodiment, it is possible to prevent a short circuit due to inadvertent contact between the current collector 2 and the terminal plate 4 on the side surface of the stacked cell 3. Therefore, even when this secondary battery is used for a long time, there is no possibility that a problem such as a short circuit occurs, and the reliability can be improved.
[0024]
Further, since the insulating layer 5 is provided at the contact portion between the current collector 2 and the terminal plate 4 on the side surface portion of the laminated cell 3, the entire surface can be covered with the exterior package 6 made of laminate, and the conventional insulation is provided. There is no need to use a case. Therefore, the structure can be simplified and the manufacturing cost can be reduced. Moreover, since the size of the stacked cell 3 in the surface direction, that is, the radial direction can be reduced, the element can be reduced in size.
[0025]
Next, more specific examples and comparative examples of the secondary battery of this embodiment will be described.
"Example 1"
As the electrode material, PQx (polyquinoxaline) is used as the negative electrode active material, PCI (polycyanoindole) is used as the positive electrode active material, and an appropriate amount of carbon powder as a conductive material is mixed and pressure-molded, and a thin plate-like negative electrode 7 and positive electrode 8 were produced. As the electrolytic solution, 40 wt% sulfuric acid was used. Next, the deposited electrodes 7 and 8 are arranged to face each other through a microporous separator 9, the current collector 2 and the gasket 10 are arranged, and heated at a predetermined pressure, time, and temperature, thereby collecting the current collector. 2 and the gasket 10 were sealed by vulcanization adhesion. Thereafter, the electrolytic solution was injected from the injection hole.
[0026]
Two or more basic cells 1 obtained in this way are stacked to form a stacked cell 3, and terminal plates 4 are arranged in close contact with

current collectors

2 and 2 on both outer ends of the stacked cell 3, respectively. Then, an epoxy resin was applied to the contact portion between the current collector 2 and the terminal plate 4 on the side surface of the laminated cell 3, and vulcanized and bonded at 120 ° C. for 1 hour.
[0027]
Here, 1000 secondary batteries in which 10 basic cells 1 of Example 1 were stacked were produced, and the failure occurrence rate due to a short circuit was investigated.
As a result, in the secondary battery of Example 1, there were 0 defects due to short circuit.
[0028]
"Comparative example"
A battery having the same configuration as in Example 1 was prepared except that no epoxy was applied between the current collector 2 and the terminal plate 4 on the side of the laminated cell 3.
Next, 1000 secondary batteries in which 10 basic cells of this comparative example were stacked were produced, and the failure rate due to short circuit was investigated.
As a result, the secondary battery of this comparative example had 416 defects due to short circuit.
[0029]
From the above results, it can be seen that the secondary battery of Example 1 is a secondary battery with extremely few defects due to a short circuit as compared with the secondary battery of the comparative example. The reason is considered that the short circuit was prevented because the insulator 5 was formed by applying and curing an epoxy resin on the contact portion between the current collector 2 and the terminal plate 4 on the side surface of the laminated cell 3. In addition, when an epoxy resin is used, it can be cured at the time of vulcanization adhesion, and the curing time can be shortened.
[0030]
"Example 2"
A secondary battery having the same configuration as that of the comparative example was manufactured except that polypropylene (PP) was sandwiched between contact portions of the terminal plate 4 and the gasket 10 and both were bonded by thermal fusion. Next, 1000 secondary batteries in which 10 basic cells 1 of Example 2 were stacked were produced, and the failure rate due to short circuit was investigated.
As a result, in the secondary battery of Example 2, there were 0 defects due to short circuit.
[0031]
From the above, it can be seen that the secondary battery of Example 2 is a secondary battery with extremely few defects due to a short circuit compared to the secondary battery of the comparative example. The reason is considered to be that the short circuit can be prevented because the insulator 5 is formed by sandwiching polypropylene (PP) at the contact portion between the terminal plate 4 and the gasket 10 and bonding them together by thermal fusion. Further, when polypropylene (PP) is used, the softening temperature is 180 ° C., and peeling between the current collector 2 and the terminal plate 4 due to high temperature use can be suppressed.
[0032]
"Example 3"
A secondary battery having the same configuration as that of the comparative example was manufactured except that an ultraviolet (UV) curable resin was applied and cured on a part of the terminal plate 4 in contact with the gasket 10.
Next, 1000 secondary batteries in which 10 basic cells 1 of Example 3 were stacked were manufactured, and the failure rate due to short circuit was examined.
As a result, in the secondary battery of Example 3, there were 0 defects due to short circuit.
[0033]
From the above, it can be seen that the secondary battery of Example 2 is a secondary battery with extremely few defects due to a short circuit compared to the secondary battery of the comparative example. The reason is that the insulator 5 is formed by applying and curing an ultraviolet (UV) curable resin to a part of the terminal plate 4 that is in contact with the gasket 10, thereby preventing a short circuit between the current collector 2 and the terminal plate 4. It is thought that it was possible.
[0034]
Example 4
An electric double layer capacitor having the same configuration as in Example 3 was produced except that activated carbon was used as the electrode material.
Next, 1000 electric double layer capacitors in which 10 basic cells 1 of Example 4 were stacked were produced, and the failure rate due to short circuit was investigated.
As a result, in the electric double layer capacitor of Example 4, there were zero defects due to a short circuit.
From the above, it was found that the electric double layer capacitor of Example 4 was an electric double layer capacitor with extremely few defects due to short circuit.
[0035]
Table 1 shows the incidence of defects due to short circuits in Examples 1 to 4 and the comparative example.
[Table 1]

[0036]
As mentioned above, although one Embodiment of the electrical storage element of this invention and its manufacturing method has been demonstrated based on drawing, a concrete structure is not limited to this Embodiment, In the range which does not deviate from the summary of this invention. The design can be changed.
[0037]
【The invention's effect】
As described above, according to the electricity storage device of the present invention , an insulating layer is provided in a contact portion between the current collector on the side surface of the stacked cell and one of the terminals, and the one terminal on the insulating layer side is provided. Since the end portion extends perpendicularly outward from the side surface of the stacked cell and is exposed to the outside through the exterior package , carelessness between the current collector and the terminal on the side surface portion of the stacked cell Can prevent short circuit due to contact . Therefore, even when this power storage element is used for a long time, there is no possibility that a short circuit or the like occurs, and the reliability can be improved.
[0038]
In addition, since it is not necessary to use a conventional insulating case, the structure can be simplified and the manufacturing cost can be reduced. In addition, since the size of the stacked cell in the surface direction, that is, the radial direction can be reduced, the element can be reduced in size.
[0039]
In addition, if the basic cell is a basic cell for a secondary battery in which the positive electrode and the negative electrode are arranged to face each other with the separation layer interposed therebetween, there is no possibility of causing a short circuit or the like, improving reliability, downsizing, and A secondary battery capable of reducing manufacturing costs can be provided.
[0040]
In addition, if the basic cell is a basic cell for an electric double layer capacitor in which a pair of polarizable electrodes are arranged to face each other via a separation layer, there is no risk of problems such as short circuits, improving reliability and downsizing. In addition, an electric double layer capacitor capable of reducing the manufacturing cost can be provided.
[0041]
According to the method for manufacturing a power storage device of the present invention, the terminals are electrically connected to both ends of the stacked cell in a state where the end of one of the terminals extends vertically outward from the side surface of the stacked cell. Next, by applying an insulating organic resin to the contact portion between the current collector on the side surface of the stacked cell and one of the terminals, and curing the organic resin, the side surface of the stacked cell An insulating layer is formed at the contact portion between the current collector of one part and one of the terminals, and then the whole is covered with an exterior package so that the end of one of the terminals is exposed to the outside. Thus, a power storage element with improved reliability and improved reliability can be easily manufactured in a simple process without using expensive equipment.
[0042]
According to another method of manufacturing the electricity storage device of the present invention, the terminals of one of the terminals are respectively connected to both ends of the stacked cell in a state in which the end of the terminal extends vertically outward from the side surface of the stacked cell. the electrically connected, then said insulating organic resin is sandwiched contact portion between the current collector and one of the terminals of the side surface portion of the stacked cell, by heat-sealing the organic resin, wherein An insulating layer is formed at the contact portion between the current collector on the side surface of the stacked cell and one of the terminals, and then the whole is covered with an exterior package so that the end of one of the terminals is exposed to the outside. Therefore, a storage element with improved reliability without the risk of a short circuit or the like can be easily manufactured in a simple process without using expensive equipment.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an internal structure of a secondary battery according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing an internal structure of a basic cell of a secondary battery according to an embodiment of the present invention.
FIG. 3 is a cross-sectional view showing an example of a conventional electric double layer capacitor.
FIG. 4 is a cross-sectional view showing another example of a conventional electric double layer capacitor.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Basic cell 2 Current collector 3 Laminated cell 4 Terminal board 5 Insulating layer 6 Outer package 7 Negative electrode 8 Positive electrode 9 Microporous separator 10 Gasket 11 Laminated cell 12 Anode terminal 13 Cathode terminal 14 Insulating case 15 Outer case 21 Current collector 22 Separator 23 Current collector 24 Gasket 25 Activated carbon electrode AC

Claims

A stacked cell formed by alternately stacking a plurality of basic cells and current collectors, and terminals that are respectively provided and electrically connected to both ends of the stacked cell;
In the basic cell, a pair of electrodes are arranged to face each other via a separation layer ,
These stacked cells and terminals are power storage elements that are covered with an exterior package,
An insulating layer is provided at a contact portion between the current collector on the side surface of the stacked cell and one of the terminals, and an end of the one terminal on the insulating layer side is perpendicular to the outside from the side of the stacked cell. A power storage element that extends and is exposed to the outside through the exterior package .

2. The storage element according to claim 1, wherein the basic cell is a secondary cell basic cell in which a positive electrode and a negative electrode are arranged to face each other with a separation layer interposed therebetween.

The electric storage element according to claim 1, wherein the basic cell is a basic cell for an electric double layer capacitor in which a pair of polarizable electrodes are arranged to face each other via a separation layer.

The electric storage element according to claim 1, wherein the insulating layer is an insulating organic resin.

The power storage element according to claim 4, wherein the organic resin is one of a thermosetting resin, an ultraviolet curable resin, and an organic resin film.

A stacked cell formed by alternately stacking a plurality of basic cells and current collectors, and terminals that are respectively provided and electrically connected to both ends of the stacked cell;
In the basic cell, a pair of electrodes are arranged to face each other via a separation layer ,
These stacked cells and terminals are a method of manufacturing a power storage element that is covered with an exterior package in a state where an end of one terminal is exposed to the outside,
With the end of one of the terminals extending vertically outward from the side surface of the stacked cell, the terminals are electrically connected to both ends of the stacked cell, respectively.
Next, an insulating organic resin is applied to a contact portion between the current collector on the side surface of the stacked cell and one of the terminals, and the organic resin is cured to thereby collect the current collector on the side surface of the stacked cell. And forming an insulating layer at the contact portion between the one terminal and
Then, the whole of the terminal is covered with an exterior package so that the end of one of the terminals is exposed to the outside, and the method for manufacturing a power storage element is provided.

A stacked cell formed by alternately stacking a plurality of basic cells and current collectors, and terminals that are respectively provided and electrically connected to both ends of the stacked cell;
In the basic cell, a pair of electrodes are arranged to face each other via a separation layer ,
These stacked cells and terminals are a method of manufacturing a power storage element that is covered with an exterior package in a state where an end of one terminal is exposed to the outside,
With the end of one of the terminals extending vertically outward from the side surface of the stacked cell, the terminals are electrically connected to both ends of the stacked cell, respectively.
Next, an insulating organic resin is sandwiched between the current collector on the side surface of the stacked cell and one of the terminals, and the organic resin is thermally fused, thereby collecting the side surface of the stacked cell. Forming an insulating layer at the contact portion between the electric body and one of the terminals;
Then, the whole of the terminal is covered with an exterior package so that the end of one of the terminals is exposed to the outside, and the method for manufacturing a power storage element is provided.