JP2004207118A - Lithium ion polymer secondary battery and its manufacturing method - Google Patents

Lithium ion polymer secondary battery and its manufacturing method Download PDF

Info

Publication number
JP2004207118A
JP2004207118A JP2002376633A JP2002376633A JP2004207118A JP 2004207118 A JP2004207118 A JP 2004207118A JP 2002376633 A JP2002376633 A JP 2002376633A JP 2002376633 A JP2002376633 A JP 2002376633A JP 2004207118 A JP2004207118 A JP 2004207118A
Authority
JP
Japan
Prior art keywords
negative electrode
positive electrode
side edge
current collector
collector foil
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP2002376633A
Other languages
Japanese (ja)
Other versions
JP4232458B2 (en
Inventor
Yusuke Watarai
祐介 渡会
Akio Mizuguchi
暁夫 水口
Akihiro Higami
晃裕 樋上
Shuhin Cho
守斌 張
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Materials Corp
Original Assignee
Mitsubishi Materials Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsubishi Materials Corp filed Critical Mitsubishi Materials Corp
Priority to JP2002376633A priority Critical patent/JP4232458B2/en
Publication of JP2004207118A publication Critical patent/JP2004207118A/en
Application granted granted Critical
Publication of JP4232458B2 publication Critical patent/JP4232458B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Classifications

    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Abstract

<P>PROBLEM TO BE SOLVED: To suppress peeling-off of a current collector foil and an active material layer, and prevent reduction of a battery capacity. <P>SOLUTION: A positive electrode sheet 11 constituted by forming a positive electrode active material layer 15 on the surface of a belt-shaped positive electrode collector foil 14 is folded in a zigzag state for twice or more, and a positive electrode terminal 16 is connected to one side edge 11a. A negative electrode sheet 13 constituted by forming a negative electrode active material layer 18 on the surface of a negative electrode collector foil 17 has an area corresponding to the folded area of the positive electrode sheet, is pinched between the folded positive electrode sheets via polymer electrolyte layers 12, and a negative electrode terminal 19 is connected to one side edge 13a. The polymer electrolyte layer has a first electrolyte layer 12a of a negative electrode side formed on the surface of the negative electrode sheet, a second electrolyte layer 12b of a negative electrode side successively installed at the first electrolyte layer of the negative electrode side and formed at the end face of the other side edge 13b of the negative electrode sheet, and a third one 12c of the negative electrode side successively installed at the second electrolyte layer of the negative electrode side and formed at the rear face of the negative electrode sheet. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、ポリマー電解質層を介装して正極シート及び負極シートを積層したリチウムイオンポリマー二次電池に関するものである。
【０００２】
【従来の技術】
従来、この種の二次電池として、帯状の負極集電体の片面に負極活物質層を形成することにより負極が構成され、帯状の正極集電体の片面に正極活物質層を形成することにより正極が構成され、上記負極及び正極をこれらの間に固体電解質層を介装して積層することにより積層電極体が構成され、更に上記負極及び正極にそれぞれリード線が取付けられた固体電解質電池が開示されている（例えば、特許文献１参照）。この固体電解質電池では、上記負極と正極とを互いに負極活物質層側と正極活物質層側とを対向させ、かつ負極及び正極間にゲル状電解質層を介装して積層した状態で折畳むことにより形成される。また負極又は正極の長手方向の端部が負極又は正極の幅方向の寸法よりも大きくなされた絶縁部材により被覆される。
【０００３】
このように構成された固体電解質電池では、負極又は正極の長手方向の端部を負極又は正極の幅方向の寸法よりも大きくなされた絶縁部材により被覆したので、積層された負極と正極との長手方向の端部付近における接触が防止され、絶縁性が保持される。この結果、電池作製時における電池内部の電気的短絡を防ぐことができるようになっている。
【０００４】
【特許文献１】
特開２０００−１７３６５７号公報
【０００５】
【発明が解決しようとする課題】
しかし、上記特許文献１に示された固体電解質電池では、負極及び正極の幅方向の端部で、負極集電体箔及び負極活物質層間で、或いは正極集電体箔及び正極活物質層間で剥離が生じるおそれがあり、これにより二次電池のサイクル特性が低下する不具合があった。
また、上記特許文献１に示された固体電解質電池では、負極集電体箔及び正極集電体箔の側面が露出しているため、積層電極体を折畳んだときに負極集電体箔及び正極集電体箔の上記露出する側面同士が接触して短絡するおそれがあった。
【０００６】
本発明の第１の目的は、集電体箔及び活物質層の側縁をポリマー電解質層にて被覆することにより、集電体箔及び活物質層の剥離を抑制でき、これにより電池容量の低下を防止できるとともに、サイクル特性、放電容量及び出力特性を向上できる、リチウムイオンポリマー二次電池を提供することにある。
本発明の第２の目的は、集電体箔の側縁をポリマー電解質層にて被覆することにより、正極シート及び負極シートの短絡を防止できる、リチウムイオンポリマー二次電池を提供することにある。
【０００７】
【課題を解決するための手段】
請求項１に係る発明は、図１及び図２に示すように、帯状の正極集電体箔１４の表面に正極活物質層１５が形成され１回折り又は２回以上の葛折りにより折畳まれかつ一方の側縁１１ａに正極端子１６が接続された正極シート１１と、正極シート１１の折畳み面積に相応した面積を有する負極集電体箔１７の表面に負極活物質層１８が形成され上記折畳まれる正極シート１１の間にポリマー電解質層１２を介して挟持されかつ一方の側縁１３ａに負極端子１９が接続された負極シート１３とを備えたリチウムイオンポリマー二次電池の改良である。
その特徴ある構成は、ポリマー電解質層１２が、負極シート１３の表面に形成された負極側第１電解質層１２ａと、負極側第１電解質層１２ａに連設され負極シート１３の他方の側縁１３ｂの端面に形成された負極側第２電解質層１２ｂとを有するところにある。
【０００８】
この請求項１に記載されたリチウムイオンポリマー二次電池では、負極シート１３の他方の側縁１３ｂをポリマー電解質層１２にて被覆することにより、負極集電体箔１７及び負極活物質層１８の剥離を抑制できるので、電池容量の低下を防止でき、電池１０のサイクル特性を向上できる。また負極活物質層１８の他方の側縁１８ｂもリチウムイオンの吸蔵及び放出に寄与するので、電池１０の放電容量及び出力特性を向上できる。更に負極シート１３の他方の側縁１３ｂをポリマー電解質層１２にて被覆することにより、負極シート１３の他方の側縁１３ｂが露出しなくなるので、正極シート１１の折畳みによる正極シート１１及び負極シート１３の接触を阻止できる。
【０００９】
請求項２に係る発明は、図９及び図１０に示すように、ポリマー電解質層４２が、正極シート１１の表面に形成された正極側第１電解質層４２ａと、正極側第１電解質層４２ａに連設され正極シート１１の他方の側縁１１ｂの端面に形成された正極側第２電解質層４２ｂとを有することを特徴とする。
この請求項２に記載されたリチウムイオンポリマー二次電池では、正極シート１１の他方の側縁１１ｂをポリマー電解質層４２にて被覆することにより、正極集電体箔１４及び正極活物質層１５の剥離を抑制できるので、電池容量の低下を防止でき、電池４０のサイクル特性を向上できる。また正極活物質層１５の他方の側縁１５ｂもリチウムイオンの吸蔵及び放出に寄与するので、電池４０の放電容量及び出力特性を向上できる。更に正極シート１１の他方の側縁１１ｂをポリマー電解質層４２にて被覆することにより、正極シート１１の他方の側縁１１ｂが露出しなくなるので、正極シート１１の折畳みによる正極シート１１及び負極シート１３の接触を阻止できる。
【００１０】
請求項３に係る発明は、図１４及び図１５に示すように、ポリマー電解質層５２が、負極シート１３の表面に形成された負極側第１電解質層１２ａと、負極側第１電解質層１２ａに連設され負極シート１３の他方の側縁１３ｂの端面に形成された負極側第２電解質層１２ｂと、正極シート１１の表面に形成された正極側第１電解質層４２ａと、正極側第１電解質層４２ａに連設され正極シート１１の他方の側縁１１ｂの端面に形成された正極側第２電解質層４２ｂとを有することを特徴とする。
この請求項３に記載されたリチウムイオンポリマー二次電池では、負極シート１３の他方の側縁１３ｂ及び正極シート１１の他方の側縁１１ｂをポリマー電解質層５２にて被覆することにより、負極集電体箔１７及び負極活物質層１８の剥離と、正極集電体箔１４及び正極活物質層１５の剥離とを抑制できるので、電池容量の低下を上記請求項１又は２より確実に防止でき、電池５０のサイクル特性を上記請求項１又は２より向上できる。また負極活物質層１８の他方の側縁１８ｂ及び正極活物質層１５の他方の側縁１５ｂもリチウムイオンの吸蔵及び放出に寄与するので、電池５０の放電容量及び出力特性を上記請求項１又は２より向上できる。更に負極シート１３の他方の側縁１３ｂ及び正極シート１１の他方の側縁１１ｂをポリマー電解質層５２にて被覆することにより、負極シート１３の他方の側縁１３ｂ及び正極シート１１の他方の側縁１１ｂが露出しなくなるので、正極シート１１の折畳みによる正極シート１１及び負極シート１３の接触を上記請求項１又は２より確実に阻止できる。
【００１１】
請求項４に係る発明は、請求項１又は３に係る発明であって、更に図１及び図２に示すように、負極側第２電解質層１２ｂに連設され負極シート１３の裏面に所定の幅及び厚さに形成された負極側第３電解質層１２ｃを更に備えたことを特徴とする。
この請求項４に記載されたリチウムイオンポリマー二次電池では、負極シート１３の他方の側縁１３ｂの上面を負極側第１電解質層１２ａにて被覆し、他方の側縁１３ｂの端面を負極側第２電解質層１２ｂにて被覆し、更に他方の側縁１３ｂの裏面を負極側第３電解質層１２ｃにて被覆するので、負極シート１３の他方の側縁１３ｂが全く露出しなくなり、正極シート１１の折畳みによる正極シート１１及び負極シート１３の接触を確実に阻止できる。
【００１２】
請求項５に係る発明は、請求項２又は３に係る発明であって、更に図９及び図１０に示すように、正極側第２電解質層４２ｂに連設され正極シート１１の裏面に所定の幅及び厚さに形成された正極側第３電解質層４２ｃを更に備えたことを特徴とする。
この請求項５に記載されたリチウムイオンポリマー二次電池では、正極シート１１の他方の側縁１１ｂの上面を正極側第１電解質層４２ａにて被覆し、他方の側縁１１ｂの端面を正極側第２電解質層４２ｂにて被覆し、更に他方の側縁１１ｂの裏面を正極側第３電解質層４２ｃにて被覆するので、正極シート１１の他方の側縁１１ｂが全く露出しなくなり、正極シート１１の折畳みによる正極シート１１及び負極シート１３の接触を確実に阻止できる。
【００１３】
請求項６に係る発明は、図４〜図６に示すように、帯状の負極集電体箔１７の表面に、一方の側縁を負極集電体箔１７の一方の側縁１７ａから所定の幅だけ内側に位置させかつ他方の側縁を負極集電体箔１７の他方の側縁１７ｂに一致させて帯状の負極活物質層１８を形成する工程と、扁平ノズル２２ａを有する塗布機用タンク２２に粘度が０．５〜４５Ｐである電解質スラリー２１を貯留する工程と、扁平ノズル２２ａの一端を負極活物質層１８の一方の側縁１８ａから所定の幅だけ幅方向外側の負極集電体箔１７上に位置させかつ扁平ノズル２２ａの他端を負極活物質層１８の他方の側縁１８ｂから所定の幅だけ幅方向外側に位置させた状態で負極集電体箔１７をその長手方向に移動させながら、扁平ノズル２２ａから電解質スラリー２１を吐出することにより、電解質スラリー２１を負極集電体箔１７の表面の一部と負極活物質層１８の全表面と負極集電体箔１７の他方の側縁１７ｂの端面と負極活物質層１８の他方の側縁１８ｂの端面と負極集電体箔１７の他方の側縁１７ｂの裏面に連続塗布する工程と、連続塗布された電解質スラリー２１を乾燥することにより、負極集電体箔１７の表面の一部及び負極活物質層１８の全表面を被覆する負極側第１電解質層１２ａと、負極集電体箔１７の他方の側縁１７ｂの端面及び負極活物質層１８の他方の側縁１８ｂの端面を被覆する負極側第２電解質層１２ｂと、負極集電体箔１７の他方の側縁１７ｂの裏面を被覆する負極側第３電解質層１２ｃとからなるポリマー電解質層１２を形成する工程と、帯状の負極集電体箔１７を負極活物質層１８及びポリマー電解質層１２とともに所定の長さに切断する工程とを含むリチウムイオンポリマー二次電池の製造方法である。
この請求項６に記載された方法でリチウムイオンポリマー二次電池を製造すると、上記請求項１に記載されたリチウムイオンポリマー二次電池を得ることができる。
【００１４】
請求項７に係る発明は、図１２に示すように、帯状の正極集電体箔１４の表面に、一方の側縁を正極集電体箔１４の一方の側縁１４ａから所定の幅だけ内側に位置させかつ他方の側縁を正極集電体箔１４の他方の側縁１４ｂに一致させて帯状の正極活物質層１５を形成する工程と、扁平ノズルを有する塗布機用タンクに粘度が０．５〜４５Ｐである電解質スラリーを貯留する工程と、扁平ノズルの一端を正極活物質層１５の一方の側縁１５ａから所定の幅だけ幅方向外側の正極集電体箔１４上に位置させかつ扁平ノズルの他端を正極活物質層１５の他方の側縁１５ｂから所定の幅だけ幅方向外側に位置させた状態で正極集電体箔１４をその長手方向に移動させながら、扁平ノズルから電解質スラリーを吐出することにより、電解質スラリーを正極集電体箔１４の表面の一部と正極活物質層１５の全表面と正極集電体箔１４の他方の側縁１４ｂの端面と正極活物質層１５の他方の側縁１５ｂの端面と正極集電体箔１４の他方の側縁１４ｂの裏面に連続塗布する工程と、連続塗布された電解質スラリーを乾燥することにより、正極集電体箔１４の表面の一部及び正極活物質層１５の全表面を被覆する正極側第１電解質層４２ａと、正極集電体箔１４の他方の側縁１４ｂの端面及び正極活物質層１５の他方の側縁１５ｂの端面を被覆する正極側第２電解質層４２ｂと、正極集電体箔１４の他方の側縁１４ｂの裏面を被覆する正極側第３電解質層４２ｃとからなるポリマー電解質層４２を形成する工程とを含むリチウムイオンポリマー二次電池の製造方法である。
この請求項７に記載された方法でリチウムイオンポリマー二次電池を製造すると、上記請求項２に記載されたリチウムイオンポリマー二次電池を得ることができる。
【００１５】
請求項８に係る発明は、図１９に示すように、帯状の負極集電体箔１７の表面に、一方の側縁を負極集電体箔１７の一方の側縁１７ａから所定の幅だけ内側に位置させかつ他方の側縁を負極集電体箔１７の他方の側縁１７ｂに一致させて帯状の負極活物質層１８を形成する工程と、扁平ノズルを有する塗布機用タンクに粘度が４５〜８０Ｐである電解質スラリーを貯留する工程と、扁平ノズルの一端を負極活物質層１８の一方の側縁１８ａから所定の幅だけ幅方向外側の負極集電体箔１７上に位置させかつ扁平ノズルの他端を負極活物質層１８の他方の側縁１８ｂから所定の幅だけ幅方向外側に位置させた状態で負極集電体箔１７をその長手方向に移動させながら、扁平ノズルから電解質スラリーを吐出することにより、電解質スラリーを負極集電体箔１７の表面の一部と負極活物質層１８の全表面と負極集電体箔１７の他方の側縁１７ｂの端面と負極活物質層１８の他方の側縁１８ｂの端面に連続塗布する工程と、連続塗布された電解質スラリーを乾燥することにより、負極集電体箔１７の表面の一部及び負極活物質層１８の全表面を被覆する負極側第１電解質層１２ａと、負極集電体箔１７の他方の側縁１７ｂの端面及び負極活物質層１８の他方の側縁１８ｂの端面を被覆する負極側第２電解質層１２ｂとからなるポリマー電解質層６２を形成する工程と、帯状の負極集電体箔１７を負極活物質層１８及びポリマー電解質層６２とともに所定の長さに切断する工程とを含むリチウムイオンポリマー二次電池の製造方法である。
この請求項８に記載されたリチウムイオンポリマー二次電池の製造方法では、比較的粘度の高い電解質スラリーを用いても、負極第１電解質層１２ａ及び負極第２電解質層１２ｂからなるポリマー電解質層６２を負極シート１３に形成できる。
【００１６】
請求項９に係る発明は、図２０に示すように、帯状の正極集電体箔１４の表面に、一方の側縁を正極集電体箔１４の一方の側縁１４ｂから所定の幅だけ内側に位置させかつ他方の側縁を正極集電体箔１４の他方の側縁１４ｂに一致させて帯状の正極活物質層１５を形成する工程と、扁平ノズルを有する塗布機用タンクに粘度が４５〜８０Ｐである電解質スラリーを貯留する工程と、扁平ノズルの一端を正極活物質層１５の一方の側縁１５ａから所定の幅だけ幅方向外側の正極集電体箔１４上に位置させかつ扁平ノズルの他端を正極活物質層１５の他方の側縁１５ｂから所定の幅だけ幅方向外側に位置させた状態で正極集電体箔１４をその長手方向に移動させながら、扁平ノズルから電解質スラリーを吐出することにより、電解質スラリーを正極集電体箔１４の表面の一部と正極活物質層１５の全表面と正極集電体箔１４の他方の側縁１４ｂの端面と正極活物質層１５の他方の側縁１５ｂの端面に連続塗布する工程と、連続塗布された電解質スラリーを乾燥することにより、正極集電体箔１４の表面の一部及び正極活物質層１５の全表面を被覆する正極側第１電解質層４２ａと、正極集電体箔１４の他方の側縁１４ｂの端面及び正極活物質層１５の他方の側縁１５ｂの端面を被覆する正極側第２電解質層４２ｂとからなるポリマー電解質層７２を形成する工程とを含むリチウムイオンポリマー二次電池の製造方法である。
この請求項９に記載されたリチウムイオンポリマー二次電池の製造方法では、比較的粘度の高い電解質スラリーを用いても、正極第１電解質層４２ａ及び正極第２電解質層４２ｂからなるポリマー電解質層７２を正極シート１１に形成できる。
【００１７】
【発明の実施の形態】
次に本発明の第１の実施の形態を図面に基づいて説明する。
図１〜図３に示すように、リチウムイオンポリマー二次電池１０は、１回折り又は２回以上の葛折りにより折畳まれる帯状の正極シート１１と、この折畳まれる正極シート１１の間にポリマー電解質層１２を介して挟持された１枚又は２枚以上の負極シート１３とを備える。正極シート１１は、帯状の正極集電体箔１４と、この正極集電体箔１４の表面に形成された帯状の正極活物質層１５とを有する。正極活物質層１５の幅は正極集電体箔１４の幅より小さく形成される（図１及び図３）。即ち、正極活物質層１５は、その一方の側縁１５ａが正極集電体箔１４の一方の側縁１４ａから所定の幅だけ幅方向内側に位置し、かつ他方の側縁１５ｂが正極集電体箔１４の他方の側縁１４ｂに一致するように形成される。また正極シート１１の一方の側縁１１ａ、即ち正極活物質層１５の形成されていない正極集電体箔１４の一方の側縁１４ａには、正極端子１６が接続される。
【００１８】
負極シート１３は、負極集電体箔１７と、この負極集電体箔１７の表面に形成された負極活物質層１８とを有し、正極集電体箔１４の折畳み面積に相応した面積を有する。また負極活物質層１８の幅は負極集電体箔１７の幅より小さく形成される（図１及び図３）。即ち、負極活物質層１８は、その一方の側縁１８ａが負極集電体箔１７の一方の側縁１７ａから所定の幅だけ幅方向内側に位置し、かつ他方の側縁１８ｂが負極集電体箔１７の他方の側縁１７ｂに一致するように形成される。更に負極シート１３の一方の側縁１３ａ、即ち負極活物質層１８の形成されていない負極集電体箔１７の一方の側縁１７ａには、負極端子１９が接続される。なお、正極活物質層１５の一方の側縁１５ａと負極シート１３の他方の側縁１３ｂとが一致し、かつ負極活物質層１８の一方の側縁１８ａと正極シート１１の他方の側縁１１ｂとが一致するように正極シート１１及び負極シート１３が積層される。換言すれば、正極集電体箔１４の一方の側縁１４ａが負極集電体箔１７の他方の側縁１７ｂから突出し、負極集電体箔１７の一方の側縁１７ａが正極集電体箔１４の他方の側縁１４ｂから突出するように正極シート１１及び負極シート１３が積層される。
【００１９】
一方、ポリマー電解質層１２は、負極シート１３の表面から他方の側縁１３ｂにわたって形成される。この実施の形態では、ポリマー電解質層１２は、負極シート１３の表面に形成された負極側第１電解質層１２ａと、負極側第１電解質層１２ａに連設され負極シート１３の他方の側縁１３ｂの端面に形成された負極側第２電解質層１２ｂと、負極側第２電解質層１２ｂに連設され負極シート１３の裏面に所定の幅及び厚さに形成された負極側第３電解質層１２ｃとを有する。負極側第１電解質層１２ａは、その一方の側縁が負極活物質層１８の一方の側縁１８ａから所定の幅だけ幅方向外側の負極集電体箔１７上に位置し、かつ他方の側縁が負極活物質層１８の他方の側縁１８ｂに一致するように、即ち負極活物質層１８の表面及び一方の側縁１８ａの端面を被覆するように形成される。また負極側第２電解質層１２ｂは負極集電体箔１７の他方の側縁１７ｂの端面及び負極活物質層１８の他方の側縁１８ｂの端面を被覆するように形成される。
【００２０】
更に負極側第３電解質層１２ｃは、負極集電体箔１７の他方の側縁１７ｂの裏面に、幅が０．５〜２０ｍｍ、好ましくは３〜１２ｍｍとなり、厚さが２〜１００μｍ、好ましくは１０〜６０μｍとなるように形成される。負極側第３電解質層１２ｃの幅を０．５〜２０ｍｍの範囲に限定したのは、０．５ｍｍ未満では負極シート１３を介装する正極シート１１の折畳み時の折りずれにより正極シート１１と負極シート１３とが短絡するおそれがあり、２０ｍｍを越えるとエネルギ密度の低下を招くとともに、負極シート１３を介装する正極シート１１の折畳み時の折りずれが２０ｍｍを越えることはあり得ないからである。また負極側第３電解質層１２ｃの厚さを２〜１００μｍの範囲に限定したのは、２μｍ未満では負極側第３電解質層１２ｃの材質が弱く、折りずれが発生したときにこの第３電解質層が切れてしまい、負極シート１３が正極シート１１に短絡するおそれがあり、１００μｍを越えると負極シート１３を介装する正極シート１１の折畳み時に第３負極側電解質層１２ｃが形成された負極シート１３の端部のみが厚くなってしまい、真空パックする際に最外部付近の正極シートが折れたり、隙間なく容器に収容できなくなるからである。
【００２１】
なお、正極集電体箔１４としてはＡｌ箔が挙げられ、正極活物質層１５の活物質としてはＬｉＣｏＯ2が挙げられる。また負極集電体箔１７としてはＣｕ箔が挙げられ、負極活物質層１８の活物質としては炭素系の活物質が挙げられる。更にポリマー電解質層１２のポリマーとしてはポリエチレンオキシド、ポリフッ化ビニリデン等が挙げられ、ポリマー電解質層１２の電解液としてはエチレンカーボネート、プロピレンカーボネート、γ-ブチロラクトン等を含む混合液が挙げられる。
【００２２】
このように構成されたリチウムイオンポリマー二次電池１０の製造方法を図１〜図８に基づいて説明する。
▲１▼ 正極シート１１の作製
先ず正極活物質層１５に含まれる活物質をＮ−メチルピロリドン溶液等に分散混合して正極活物質スラリーを調製する。次にこのスラリーを帯状の正極集電体箔１４の上面に、ドクタブレード法やスクリーン印刷法などにより連続塗布して乾燥する（図７（ｂ））。このとき正極活物質層１５の一方の側縁１５ａを正極集電体箔１４の一方の側縁１４ａから所定の幅だけ幅方向内側にずらし、かつ正極活物質層１５の他方の側縁１５ｂを正極集電体箔１４の他方の側縁１４ａに一致させた状態で、正極活物質層１５を正極集電体箔１４の上面に帯状に形成する。これにより正極シート１１が作製される。
【００２３】
▲２▼ 帯状の負極シート１３の作製
先ず負極活物質層１８に含まれる活物質をＮ−メチルピロリドン溶液等に分散混合して負極活物質スラリーを調製する。次にこのスラリーを帯状の負極集電体箔１７の上面に、ドクターブレード法やスクリーン印刷法などにより連続塗布して乾燥する（図６（ｂ））。このとき負極活物質層１８の一方の側縁１８ａを負極集電体箔１７の一方の側縁１７ａから所定の幅だけ幅方向内側にずらし、かつ負極活物質層１８の他方の側縁１８ｂを負極集電体箔１７の他方の側縁１７ｂに一致させた状態で、負極活物質層１８を負極集電体箔１７の上面に帯状に形成する。これにより帯状の負極シート１３が作製される。
【００２４】
▲３▼ 負極シート１３へのポリマー電解質層１２の形成
先ずポリマー、電解液及びリチウム金属塩を混合してなり、粘度が０．５〜４５Ｐ（ポアズ）である電解質スラリー２１（図４及び図５）を調製する。次いでこのスラリーを帯状の負極集電体箔１７及び負極活物質層１８の表面及び側縁にドクタブレード法により連続塗布する。このとき図４及び図５に示すように、電解質スラリー２１を扁平ノズル２２ａを有する塗布機用タンク２２に貯留し、扁平ノズル２２ａの一端を負極活物質層１８の一方の側縁１８ａから所定の幅だけ幅方向外側の負極集電体箔１７上に位置させ、かつ扁平ノズル２２ａの他端を負極活物質層１８の他方の側縁１８ｂから所定の幅だけ幅方向外側のローラ２３上に位置させた状態で、負極集電体箔１７をその長手方向に移動させながら、扁平ノズル２２ａから電解質スラリー２１を連続的に吐出する。これにより電解質スラリー２１が、負極集電体箔１７の表面の一部、負極活物質層１８の全表面、負極集電体箔１７の他方の側縁１７ｂの端面、負極活物質層１８の他方の側縁１８ｂの端面及び負極集電体箔１７の他方の側縁１７ｂの裏面に連続塗布される。ここで電解質スラリー２１が負極集電体箔１７の他方の側縁１７ｂの裏面にも塗布されるのは、上記スラリー２１の粘度が０．５〜４５Ｐと比較的低いため、このスラリー２１が負極集電体箔１７の他方の側縁１７ｂの裏面にも回り込むためである。なお、図５の符号２３ａはローラ２３外周面に付着したスラリー２１を掻き落とすためのスクレーパである。
【００２５】
次に上記連続塗布された電解質スラリー２１を乾燥することにより、負極集電体箔１７の表面の一部及び負極活物質層１８の全表面を被覆する負極側第１電解質層１２ａと、負極集電体箔１７の他方の側縁１７ｂの端面及び負極活物質層１８の他方の側縁１８ｂの端面を被覆する負極側第２電解質層１２ｂと、負極集電体箔１７の他方の側縁１７ｂの裏面を被覆する負極側第３電解質層１２ｃとからなるポリマー電解質層１２を形成する（図６（ｃ））。更に帯状の負極シート１３を帯状のポリマー電解質層１２とともに所定の長さに切断することにより、ポリマー電解質層１２を有する最終形状の負極シート１３が作製される（図６（ｄ））。
【００２６】
▲４▼ 正極シート１１及び負極シート１３の熱圧着
先ず帯状の正極活物質層１５を上に向けた正極シート１１上に、ポリマー電解質層２１を下に向けた複数枚の負極シート１３を所定の間隔をあけて配置し、積層体２４を作製する（図８）。次に所定の温度に加熱されかつ実線矢印の方向に回転する一対のローラ２５，２５間に、上記積層体２４を破線矢印で示す方向から挿入する。これによりポリマー電解質層１２を介装した状態で正極シート１１及び負極シート１３が熱圧着される。なお、帯状の正極集電体箔１４の一方の側縁１４ａが複数枚の負極シート１３の他方の側縁１３ｂから突出し、複数枚の負極集電体箔１７の一方の側縁１７ａが帯状の正極シート１１の他方の側縁１１ｂから突出するように、正極シート１１上に負極シート１３が配置される。
【００２７】
▲５▼ 積層体２４の折畳み
上記熱圧着された積層体２４を葛折りにより折畳む。即ち、図３に示すように、帯状の正極シート１１のうち負極シート１３の配置されていない部分を、交互にジグザグに折曲げて折畳む。このとき帯状の正極集電体箔１４の一方の側縁１４ａは複数枚の負極集電体箔１７の他方の側縁１７ｂから突出した状態で積層され、複数枚の負極集電体箔１７の一方の側縁１７ａは帯状の正極集電体箔１４の他方の側縁１４ｂから突出した状態で積層される。このように折畳まれた積層体２４では、折畳んで重ねられた正極シート１１の間に、この折畳み面積に相応した面積を有する複数枚の負極シート１３がポリマー電解質層１２を介して挟持される。なお、複数枚の負極シート１３の他方の側縁１３ｂからは正極集電体箔１４の一方の側縁１４ａがジグザグに折曲った状態で突出し、この突出部には止め金具２６が貫通されるとともに、この止め金具２６により正極端子１６の一端が突出部に固着される（図１及び図３）。また正極シート１１の他方の側縁１１ｂからは複数枚の負極集電体箔１７の一方の側縁１７ａがそれぞれ突出し、これらの突出部には止め金具２７が貫通されるとともに、この止め金具２７により負極端子１９の一端が突出部に固着される。
【００２８】
▲６▼ 折畳まれた積層体２４の密封
上記折畳まれかつ正極端子１６及び負極端子１９を有する積層体２４は、ポリプロピレンがラミネートされたアルミニウム箔からなる一対のパッケージシート２８，２８により密封される（図１〜図３）。具体的には、上記折畳まれかつ正極端子１６及び負極端子１９を有する積層体２４は、真空雰囲気中で、しかも正極端子１６の他端及び負極端子１９の他端はパッケージシート２８，２８外に突出させた状態で、一対のパッケージシート２８，２８の周囲を熱圧着することにより密封される。このようにして作製されたリチウムイオンポリマー二次電池１０は、パッケージシート２８，２８から突出する正極端子１６の他端及び負極端子１９の他端を電池１０の端子として使用することにより所望の電力を得ることができる。
【００２９】
このように製造されたリチウムイオンポリマー二次電池１０では、負極シート１３の他方の側縁１３ｂをポリマー電解質層１２にて被覆する、即ち負極側第１電解質層１２ａの他方の側縁にて負極活物質層１８の他方の側縁１８ｂの上面を被覆し、負極側第２電解質層１２ｂにて負極集電体箔１７の他方の側縁１７ｂの端面及び負極活物質層１８の他方の側縁１８ｂの端面を被覆し、更に負極側第３電解質層１２ｃにて負極集電体箔１７の他方の側縁１７ｂの裏面を被覆することにより、負極集電体箔１７及び負極活物質層１８の剥離を抑制できる。この結果、電池容量の低下を防止でき、負極活物質層１８の乾燥を抑制できるので、電池１０のサイクル特性を向上できる。また負極活物質層１８の他方の側縁１８ｂもリチウムイオンの吸蔵及び放出に寄与するので、電池１０の放電容量及び出力特性を向上できる。
【００３０】
更に負極シート１３の他方の側縁１３ｂをポリマー電解質層１２にて被覆することにより、負極集電体箔１７の他方の側縁１７ｂ及び負極活物質層１８の他方の側縁１８ｂが露出しなくなる。この結果、積層体２４を折畳んで組立てたときに、正極シート１１及び負極シート１３が接触しなくなるので、電池１０内での短絡を防止できる。
【００３１】
図９〜図１３は本発明の第２の実施の形態を示す。図９〜図１３において図１〜図８と同一符号は同一部品を示す。
この実施の形態では、ポリマー電解質層４２が、負極シート１３ではなく、正極シート１１の表面から他方の側縁１１ｂにわたって形成される（図９、図１２及び図１３）。このポリマー電解質層４２は、正極シート１１の表面に形成された正極側第１電解質層４２ａと、正極側第１電解質層４２ａに連設され正極シート１１の他方の側縁１１ｂの端面に形成された正極側第２電解質層４２ｂと、正極側第２電解質層４２ｂに連設され正極シート１１の裏面に所定の幅及び厚さに形成された正極側第３電解質層４２ｃとを有する。正極側第１電解質層４２ａは、その一方の側縁が正極活物質層１５の一方の側縁１５ａから所定の幅だけ幅方向外側の正極集電体箔１４上に位置し、かつ他方の側縁が正極活物質層１５の他方の側縁１５ｂに一致するように、即ち正極活物質層１５の表面及び一方の側縁１５ａの端面を被覆するように形成される。また正極側第２電解質層４２ｂは正極集電体箔１４の他方の側縁１４ｂの端面及び正極活物質層１５の他方の側縁１５ｂの端面を被覆するように形成される。
【００３２】
更に正極側第３電解質層４２ｃは、正極集電体箔１４の他方の側縁１４ｂの裏面に、幅が０．５〜２０ｍｍ、好ましくは３〜１２ｍｍとなり、厚さが２〜１００μｍ、好ましくは１０〜６０μｍとなるように形成される。正極側第３電解質層４２ｃの幅を０．５〜２０ｍｍの範囲に限定したのは、第１の実施の形態の負極側第３電解質層の幅を０．５〜２０ｍｍの範囲に限定した理由と同様である。また正極側第３電解質層４２ｃの厚さを２〜１００ｍｍの範囲に限定したのは、第１の実施の形態の負極側第３電解質層の厚さを２〜１００ｍｍの範囲に限定した理由と同様である。上記以外は第１の実施の形態と同一に構成される。
【００３３】
このように構成されたリチウムイオンポリマー二次電池４０の製造方法を説明する。
▲１▼ 正極シート１１の作製
正極シート１１は第１の実施の形態の正極シートと同様にして作製される（図１２（ｂ））。
▲２▼ 正極シート１１へのポリマー電解質層４２の形成
先ずポリマー、電解液及びリチウム金属塩を混合してなり、粘度が０．５〜４５Ｐである電解質スラリーを調製する。次いでこのスラリーを帯状の正極集電体箔１４及び正極活物質層１５の表面及び側縁にドクタブレード法により連続塗布する。このとき電解質スラリーを、第１の実施の形態と同一の扁平ノズルを有する塗布機用タンクに貯留し、扁平ノズルの一端を正極活物質層１５の一方の側縁１５ａから所定の幅だけ幅方向外側の正極集電体箔１４上に位置させ、かつ扁平ノズルの他端を正極活物質層１５の他方の側縁１５ｂから所定の幅だけ幅方向外側のローラ上に位置させた状態で、正極集電体箔１４をその長手方向に移動させながら、扁平ノズルから電解質スラリーを連続的に吐出する。これにより電解質スラリーが、正極集電体箔１４の表面の一部、正極活物質層１５の全表面、正極集電体箔１４の他方の側縁１４ｂの端面、正極活物質層１５の他方の側縁１５ｂの端面及び正極集電体箔１４の他方の側縁１４ｂの裏面に連続塗布される。ここで電解質スラリーが正極集電体箔１４の他方の側縁１４ｂの裏面にも塗布されるのは、上記スラリーの粘度が０．５〜４５Ｐと比較的低いため、このスラリーが正極集電体箔１４の他方の側縁１４ｂの裏面にも回り込むためである。
【００３４】
次に上記連続塗布された電解質スラリーを乾燥することにより、正極集電体箔１４の表面の一部及び正極活物質層１５の全表面を被覆する正極側第１電解質層４２ａと、正極集電体箔１４の他方の側縁１４ｂの端面及び正極活物質層１５の他方の側縁１５ｂの端面を被覆する正極側第２電解質層４２ｂと、正極集電体箔１４の他方の側縁１４ｂの裏面を被覆する正極側第３電解質層４２ｃとからなるポリマー電解質層４２を形成する（図１２（ｃ））。これによりポリマー電解質層４２を有する正極シート１１が作製される。
【００３５】
▲３▼ 負極シート１３の作製
帯状の負極シート１３は第１の実施の形態の帯状の負極シートと同様にして作製され（図１１（ｂ））、この帯状の負極シート１３を所定の長さに切断することにより、最終形状の複数枚の負極シート１３が作製される（図１１（ｃ））。
▲４▼ 正極シート１１及び負極シート１３の熱圧着
先ずポリマー電解質層４２を上に向けた正極シート１１上に、負極活物質層１８を下に向けた複数枚の負極シート１３を所定の間隔をあけて配置し、積層体４４を作製する（図１３）。次に所定の温度に加熱されかつ実線矢印の方向に回転する一対のローラ２５，２５間に、上記積層体４４を破線矢印で示す方向から挿入する。これによりポリマー電解質層４２を介装した状態で正極シート１１及び負極シート１３が熱圧着される。なお、帯状の正極集電体箔１４の一方の側縁１４ａが複数枚の負極シート１３の他方の側縁１３ｂから突出し、複数枚の負極集電体箔１７の一方の側縁１７ａが帯状の正極シート１１の他方の側縁１１ｂから突出するように、正極シート１１上に負極シート１３が配置される。
▲５▼ 積層体４４の折畳み及びこの折畳まれた積層体４４の密封
上記積層体４４の折畳み作業及びこの折畳まれた積層体４４の密封作業は、第１の実施の形態と同様に行われる。
【００３６】
このように製造されたリチウムイオンポリマー二次電池４０では、正極シート１１の他方の側縁１１ｂをポリマー電解質層４２にて被覆する、即ち正極側第１電解質層４２ａの他方の側縁にて正極活物質層１５の他方の側縁１５ｂの上面を被覆し、正極側第２電解質層４２ｂにて正極集電体箔１４の他方の側縁１４ｂの端面及び正極活物質層１５の他方の側縁１５ｂの端面を被覆し、更に正極側第３電解質層４２ｃにて正極集電体箔１４の他方の側縁１４ｂの裏面を被覆することにより、正極集電体箔１４及び正極活物質層１５の剥離を抑制できる。この結果、電池容量の低下を防止でき、正極活物質層１５の乾燥を抑制できるので、電池４０のサイクル特性を向上できる。また正極活物質層１５の他方の側縁１５ｂもリチウムイオンの吸蔵及び放出に寄与するので、電池４０の放電容量及び出力特性を向上できる。
【００３７】
更に正極シート１１の他方の側縁１１ｂをポリマー電解質層４２にて被覆することにより、正極シート１１の他方の側縁１１ｂが露出しなくなる。この結果、積層体４４を折畳んで組立てたときに、正極シート１１及び負極シート１３が接触しなくなるので、電池４０内での短絡を防止できる。
【００３８】
図１４〜図１８は本発明の第３の実施の形態を示す。図１４〜図１８において図１〜図１３と同一符号は同一部品を示す。
この実施の形態では、ポリマー電解質層５２が、負極シート１３の表面から他方の側縁１３ｂにわたって形成され、かつ正極シート１１の表面から他方の側縁１１ｂにわたって形成される。ポリマー電解質層５２は、第１の実施の形態と同一の負極側第１電解質層１２ａ、負極側第２電解質層１２ｂ及び負極側第３電解質層１２ｃと、第２の実施の形態と同一の正極側第１電解質層４２ａ、正極側第２電解質層４２ｂ及び正極側第３電解質層４２ｃとを有する。上記以外は第１の実施の形態と同一に構成される。
【００３９】
このように構成されたリチウムイオンポリマー二次電池５０の製造方法を説明する。
▲１▼ 正極シート１１の作製及び正極シート１１へのポリマー電解質層５２の形成
正極シート１１は第２の実施の形態と同様にして作製され、この正極シート１１には第２の実施の形態と同様にして正極側第１電解質層４２ａ、正極側第２電解質層４２ｂ及び正極側第３電解質層４２ｃがそれぞれ形成される。
▲２▼ 負極シート１３の作製及び負極シート１３へのポリマー電解質層５２の形成
負極シート１３は第１の実施の形態と同様にして作製され、この負極シート１３には第１の実施の形態と同様にして負極側第１電解質層１２ａ、負極側第２電解質層１２ｂ及び負極側第３電解質層１２ｃがそれぞれ形成される。
【００４０】
▲３▼ 正極シート１１及び負極シート１３の熱圧着
正極側第１電解質層４２ａを上に向けた正極シート１１上に、負極側第１電解質層１２ａを下に向けた複数枚の負極シート１３を所定の間隔をあけて配置し、積層体５４を作製した後（図１８）、第１の実施の形態と同様にして正極シート１１及び負極シート１３をポリマー電解質層５２を介して熱圧着する。
▲４▼ 積層体５４の折畳み及び折畳まれた積層体５４の密封
上記積層体５４の折畳み作業及びこの折畳まれた積層体５４の密封作業は、第１の実施の形態と同様に行われる。
【００４１】
このように製造されたリチウムイオンポリマー二次電池５０では、負極シート１３の他方の側縁１３ｂ及び正極シート１１の他方の側縁１１ｂをポリマー電解質層５２にて被覆する、即ち負極側第１電解質層１２ａの他方の側縁にて負極活物質層１８の他方の側縁１８ｂの上面を被覆し、負極側第２電解質層１２ｂにて負極集電体箔１７の他方の側縁１７ｂの端面及び負極活物質層１８の他方の側縁１８ｂの端面を被覆し、負極側第３電解質層１２ｃにて負極集電体箔１７の他方の側縁１７ｂの裏面を被覆し、正極側第１電解質層４２ａの他方の側縁にて正極活物質層１５の他方の側縁１５ｂの上面を被覆し、正極側第２電解質層４２ｂにて正極集電体箔１４の他方の側縁１４ｂの端面及び正極活物質層１５の他方の側縁１５ｂの端面を被覆し、更に正極側第３電解質層４２ｃにて正極集電体箔１４の他方の側縁１４ｂの裏面を被覆することにより、負極集電体箔１７及び負極活物質層１８の剥離と、正極集電体箔１４及び正極活物質層１５の剥離とを抑制できる。この結果、電池容量の低下を防止でき、負極活物質層１８及び正極活物質１５層の乾燥を抑制できるので、電池５０のサイクル特性を第１又は第２の実施の形態の電池より向上できる。また負極活物質層１８の他方の側縁１８ｂ及び正極活物質層１５の他方の側縁１５ｂもリチウムイオンの吸蔵及び放出に寄与するので、電池５０の放電容量及び出力特性を第１又は第２の実施の形態の電池より向上できる。
【００４２】
更に負極シート１３の他方の側縁１３ｂ及び正極シート１１の他方の側縁１１ｂをポリマー電解質層５２にて被覆することにより、負極シート１３の他方の側縁１３ｂ及び正極シート１１の他方の側縁１１ｂが露出しなくなる。この結果、積層体５４を折畳んで組立てたときに、正極シート１１及び負極シート１３が接触しなくなるので、電池５０内での短絡を確実に防止できる。
【００４３】
図１９は本発明の第４の実施の形態を示す。図１９において図１と同一符号は同一部品を示す。
この実施の形態では、ポリマー電解質層６２が負極シート１３の表面から他方の側縁１３ｂにわたって形成され、負極シート１３の表面に形成された負極側第１電解質層１２ａと、負極側第１電解質層１２ａに連設され負極シート１３の他方の側縁１３ｂの端面に形成された負極側第２電解質層１２ｂとを有する。なお、この実施の形態では、第１の実施の形態において負極シートの裏面に形成された負極側第３電解質層は形成されない。上記以外は第１の実施の形態と同一に構成される。
【００４４】
このように構成されたリチウムイオンポリマー二次電池６０の製造方法を説明する。
▲１▼ 正極シート１１の作製
正極シート１１は第１の実施の形態と同様にして作製される。
▲２▼ 帯状の負極シート１３の作製
帯状の負極シート１３は第１の実施の形態と同様にして作製される。
【００４５】
▲３▼ 負極シート１３へのポリマー電解質層６２の形成
先ずポリマー、電解液及びリチウム金属塩を混合してなり、粘度が４５〜８０Ｐである電解質スラリーを調製する。次いでこのスラリーを、第１の実施の形態と同様にして、帯状の負極集電体箔１７及び負極活物質層１８の表面及び側縁にドクタブレード法により連続塗布する。これにより電解質スラリーが、負極集電体箔１７の表面の一部、負極活物質層１８の全表面、負極集電体箔１７の他方の側縁１７ｂの端面及び負極活物質層１８の他方の側縁１８ｂの端面に連続塗布される。ここで電解質スラリーが負極集電体箔１７の他方の側縁１７ｂの裏面に回り込まないのは、上記スラリーの粘度が４５〜８０Ｐと比較的高いためである。
【００４６】
次に上記連続塗布された電解質スラリーを乾燥することにより、負極集電体箔１７の表面の一部及び負極活物質層１８の全表面を被覆する負極側第１電解質層１２ａと、負極集電体箔１７の他方の側縁１７ｂの端面及び負極活物質層１８の他方の側縁１８ｂの端面を被覆する負極側第２電解質層１２ｂとからなるポリマー電解質層６２を形成する。更に帯状の負極シート１３を帯状のポリマー電解質層６２とともに所定の長さに切断することにより、ポリマー電解質層６２を有する最終形状の負極シート１３が作製される。
【００４７】
▲４▼ 正極シート１１及び負極シート１３の熱圧着
正極活物質層１５を上に向けた正極シート１１上に、負極側第１電解質層１２ａを下に向けた複数枚の負極シート１３を所定の間隔をあけて配置し、積層体を作製した後、第１の実施の形態と同様にして正極シート１１及び負極シート１３をポリマー電解質層６２を介して熱圧着する。
▲５▼ 積層体の折畳み及び折畳まれた積層体の密封
上記積層体の折畳み作業及びこの折畳まれた積層体の密封作業は、第１の実施の形態と同様に行われる。
【００４８】
このように製造されたリチウムイオンポリマー二次電池６０では、負極シート１３の他方の側縁１３ｂをポリマー電解質層６２にて被覆する、即ち負極側第１電解質層１２ａの他方の側縁にて負極活物質層１８の他方の側縁１８ｂの上面を被覆し、負極側第２電解質層１２ｂにて負極集電体箔１７の他方の側縁１７ｂの端面及び負極活物質層１８の他方の側縁１８ｂの端面を被覆することにより、負極集電体箔１７及び負極活物質層１８の剥離を抑制できる。この結果、電池容量の低下を防止でき、負極活物質層１８の乾燥を抑制できるので、電池６０のサイクル特性を向上できる。また負極活物質層１８の他方の側縁１８ｂもリチウムイオンの吸蔵及び放出に寄与するので、電池６０の放電容量及び出力特性を向上できる。
【００４９】
更に負極シート１３の他方の側縁１３ｂをポリマー電解質層６２にて被覆することにより、負極シート１３の他方の側縁１３ｂの端面が露出しなくなる。この結果、積層体を折畳んで組立てたときに、正極シート１１及び負極シート１３が接触しなくなるので、電池６０内での短絡を防止できる。
【００５０】
図２０は本発明の第５の実施の形態を示す。図２０において図９と同一符号は同一部品を示す。
この実施の形態では、ポリマー電解質層７２が正極シート１１の表面から他方の側縁にわたって形成され、正極シート１１の表面に形成された正極側第１電解質層４２ａと、正極側第１電解質層４２ａに連設され正極シート１１の他方の側縁１１ｂの端面に形成された正極側第２電解質層４２ｂとを有する。なお、この実施の形態では、第２の実施の形態において正極シートの裏面に形成された正極側第３電解質層は形成されない。上記以外は第２の実施の形態と同一に構成される。
【００５１】
このように構成されたリチウムイオンポリマー二次電池７０の製造方法を説明する。
▲１▼ 正極シート１１の作製
正極シート１１は第１の実施の形態と同様にして作製される。
▲２▼ 正極シート１１へのポリマー電解質層７２の形成
先ずポリマー、電解液及びリチウム金属塩を混合してなり、粘度が４５〜８０Ｐである電解質スラリーを調製する。次いでこのスラリーを、第２の実施の形態と同様にして、帯状の正極集電体箔１４及び正極活物質層１５の表面及び側縁にドクタブレード法により連続塗布する。これにより電解質スラリーが、正極集電体箔１４の表面の一部、正極活物質層１５の全表面、正極集電体箔１４の他方の側縁１４ｂの端面及び正極活物質層１５の他方の側縁１５ｂの端面に連続塗布される。ここで電解質スラリーが正極集電体箔１４の他方の側縁１４ｂの裏面に回り込まないのは、上記スラリーの粘度が４５〜８０Ｐと比較的高いためである。次に上記連続塗布された電解質スラリーを乾燥することにより、正極集電体箔１４の表面の一部及び正極活物質層１５の全表面を被覆する正極側第１電解質層４２ａと、正極集電体箔１４の他方の側縁１４ｂの端面及び正極活物質層１５の他方の側縁１５ａの端面を被覆する正極側第２電解質層４２ｂとからなるポリマー電解質層７２を形成する。これによりポリマー電解質層７２を有する帯状の正極シート１１が作製される。
【００５２】
▲３▼ 負極シート１３の作製
負極シート１３は第２の実施の形態と同様にして作製される。
▲４▼ 正極シート１１及び負極シート１３の熱圧着
正極側第１電解質層４２ａを上に向けた正極シート１１上に、負極活物質層１８を下に向けた複数枚の負極シート１３を所定の間隔をあけて配置し、積層体を作製した後、第１の実施の形態と同様にして正極シート１１及び負極シート１３をポリマー電解質層７２を介して熱圧着する。
▲５▼ 積層体の折畳み及び折畳まれた積層体の密封
上記積層体の折畳み作業及びこの折畳まれた積層体の密封作業は、第１の実施の形態と同様に行われる。
【００５３】
このように製造されたリチウムイオンポリマー二次電池７０では、正極シート１１の他方の側縁１１ｂをポリマー電解質層７２にて被覆する、即ち正極側第１電解質層４２ａの他方の側縁にて正極活物質層１５の他方の側縁１５ｂの上面を被覆し、正極側第２電解質層４２ｂにて正極集電体箔１４の他方の側縁１４ｂの端面及び正極活物質層１５の他方の側縁１５ｂの端面を被覆することにより、正極集電体箔１４及び正極活物質層１５の剥離を抑制できる。この結果、電池容量の低下を防止でき、正極活物質層１５の乾燥を抑制できるので、電池７０のサイクル特性を向上できる。また正極活物質層１５の他方の側縁１５ｂもリチウムイオンの吸蔵及び放出に寄与するので、電池７０の放電容量及び出力特性を向上できる。
【００５４】
更に正極シート１１の他方の側縁１１ｂをポリマー電解質層７２にて被覆することにより、正極シート１１の他方の側縁１１ｂの端面が露出しなくなる。この結果、積層体を折畳んで組立てたときに、正極シート１１及び負極シート１３が接触しなくなるので、電池７０内での短絡を防止できる。
【００５５】
図２１は本発明の第６の実施の形態を示す。図２１において図１４と同一符号は同一部品を示す。
この実施の形態では、ポリマー電解質層８２が、負極シート１３の表面から他方の側縁１３ｂにわたって形成され、かつ正極シート１１の表面から他方の側縁１１ｂにわたって形成される。ポリマー電解質層８２は、第４の実施の形態のポリマー電解質層と同一の負極側第１電解質層１２ａ及び負極側第２電解質層１２ｂと、第５の実施の形態のポリマー電解質層と同一の正極側第１電解質層４２ａ及び正極側第２電解質層４２ｂとを有する。なお、この実施の形態では、第３の実施の形態において負極シートの裏面に形成された負極側第３電解質層と正極シートの裏面に形成された正極側第３電解質層とは形成されない。上記以外は第３の実施の形態と同一に構成される。
【００５６】
このように構成されたリチウムイオンポリマー二次電池８０の製造方法を説明する。
▲１▼ 正極シート１１の作製及び正極シート１１へのポリマー電解質層８２の形成
正極シート１１は第５の実施の形態と同様にして作製され、この正極シート１１には第５の実施の形態と同様にして正極側第１電解質層４２ａ及び正極側第２電解質層４２ｂがそれぞれ形成される。
▲２▼ 負極シート１３の作製及び負極シート１３へのポリマー電解質層８２の形成
負極シート１３は第４の実施の形態と同様にして作製され、この負極シート１３には第４の実施の形態と同様にして負極側第１電解質層１２ａ及び負極側第２電解質層１２ｂがそれぞれ形成される。
【００５７】
▲３▼ 正極シート１１及び負極シート１３の熱圧着
正極側第１電解質層４２ａを上に向けた正極シート１１上に、負極側第１電解質層１２ａを下に向けた複数枚の負極シート１３を所定の間隔をあけて配置し、積層体を作製した後、第１の実施の形態と同様にして正極シート１１及び負極シート１３をポリマー電解質層８２を介して熱圧着する。
▲４▼ 積層体の折畳み及び折畳まれた積層体の密封
上記積層体の折畳み作業及びこの折畳まれた積層体の密封作業は、第１の実施の形態と同様に行われる。
【００５８】
このように製造されたリチウムイオンポリマー二次電池８０では、負極シート１３の他方の側縁１３ｂ及び正極シート１１の他方の側縁１１ｂをポリマー電解質層８２にて被覆する、即ち負極側第１電解質層１２ａの他方の側縁にて負極活物質層１５の他方の側縁１５ｂの上面を被覆し、負極側第２電解質層１２ｂにて負極集電体箔１７の他方の側縁１７ｂの端面及び負極活物質層１８の他方の側縁１８ｂの端面を被覆し、正極側第１電解質層４２ａの他方の側縁にて正極活物質層１５の他方の側縁１５ｂの上面を被覆し、更に正極側第２電解質層４２ｂにて正極集電体箔１４の他方の側縁１４ｂの端面及び正極活物質層１５の他方の側縁１５ｂの端面を被覆することにより、負極集電体箔１７及び負極活物質層１８の剥離と、正極集電体箔１４及び正極活物質層１５の剥離とを抑制できる。この結果、電池容量の低下を防止でき、負極活物質層１８及び正極活物質層１５の乾燥を抑制できるので、電池８０のサイクル特性を第４又は第５の実施の形態の電池より向上できる。また負極活物質層１８の他方の側縁１８ｂ及び正極活物質層１５の他方の側縁１５ｂもリチウムイオンの吸蔵及び放出に寄与するので、電池８０の放電容量及び出力特性を第４又は第５の実施の形態の電池より向上できる。
【００５９】
更に負極シート１３の他方の側縁１３ｂ及び正極シート１１の他方の側縁１１ｂをポリマー電解質層８２にて被覆することにより、負極シート１３の他方の側縁１３ｂの端面と、正極シート１１の他方の側縁１１ｂの端面とが露出しなくなる。この結果、積層体を折畳んで組立てたときに、正極シート１１及び負極シート１３が接触しなくなるので、電池８０内での短絡を確実に防止できる。
【００６０】
【実施例】
次に本発明の実施例を比較例とともに詳しく説明する。
＜実施例１＞
先ず帯状の正極シート１１を作製した（図７）。即ち、ＬｉＣｏＯ2粉末１９４ｇと黒鉛粉末（商品名；ケッチェンブラック）６ｇを、ポリフッ化ビニリデンのＮ−メチルピロリドン溶液に分散混合して、正極活物質スラリーを作製した後に、この正極活物質スラリーを、幅が２０ｃｍであり長さが３０ｍであるＡｌ製の正極集電体箔１４の上面に、ドクターブレード法により連続塗布し乾燥して、帯状の正極集電体箔１４上面に帯状の正極活物質層１５を形成した。
【００６１】
一方、複数枚の負極シート１３を作製した（図６）。即ち、幅が２０ｃｍであり長さが３０ｍであるＣｕ製の負極集電体箔１７の上面に、鱗片状天然黒鉛粉末５００ｇをポリフッ化ビニリデンのＮ−メチルピロリドン溶液に分散混合した負極活物質スラリーを、ドクタブレード法により間欠塗布し乾燥して、帯状の負極集電体箔１７上面に帯状の負極活物質層１８を形成した。次に１８０ｇのフッ化ビニリデン−ヘキサフルオロプロピレン共重合体（エルフアトケム製、Ｋｙｎａｒ２８１０；ヘキサフルオロプロピレン１２ｗｔ％含有品）を１０００ｇのジメチルカーボネートに５０℃で溶解し、更に電解液として１モル／リットルの濃度となるように６フッ化リンリチウム（ＬｉＰＦ6）が溶解した３６０ｇのエチレンカーボネート・プロピレンカーボネート混合溶液（重量比で２：１）を撹拌混合して、粘度が２２Ｐである電解質スラリーを調製した。この電解質スラリーを、負極集電体箔１７及び負極活物質層１８の上面及び他方の側縁に、ドクターブレード法により連続塗布した（図４及び図５）。
【００６２】
このとき電解質スラリー２１を扁平ノズル２２ａを有する塗布機用タンク２２に貯留し、扁平ノズル２２ａの一端を負極活物質層１８の一方の側縁１８ｂから所定の幅だけ幅方向外側の負極集電体箔１７上に位置させ、かつ扁平ノズル２２ａの他端を負極活物質層１８の他方の側縁１８ｂから所定の幅だけ幅方向外側のローラ２３上に位置させた状態で、負極集電体箔１７をその長手方向に移動させながら、扁平ノズル２２ａから電解質スラリー２１を連続的に吐出した。これにより電解質スラリー２１が、負極集電体箔１７の表面の一部、負極活物質層１８の全表面、負極集電体箔１７の他方の側縁１７ｂの端面、負極活物質層１８の他方の側縁１８ｂの端面及び負極集電体箔１７の他方の側縁１７ｂの裏面に連続塗布された。ここで電解質スラリー２１の粘度が２２Ｐと低かったため、上記スラリー２１が負極集電体箔１７の他方の側縁１７ｂの裏面にも回り込んだ。
【００６３】
上記連続塗布された電解質スラリー２１を乾燥することにより、負極集電体箔１７の表面の一部及び負極活物質層１８の全表面を被覆する負極側第１電解質層１２ａと、負極集電体箔１７の他方の側縁１７ｂの端面及び負極活物質層１８の他方の側縁１８ｂの端面を被覆する負極側第２電解質層１２ｂと、負極集電体箔１７の他方の側縁１７ｂの裏面を被覆する負極側第３電解質層１２ｃとからなるポリマー電解質層１２が形成された（図６（ｃ））。ここで負極側第３電解質層１２ｃの幅は５ｍｍであり、厚さは３５μｍであった。更にポリマー電解質層１２が形成された帯状の負極シート１３を、ポリマー電解質層１２とともに切断して、ポリマー電解質層１２を有する幅及び長さがそれぞれ１０ｃｍ及び１２ｃｍである１０枚の負極シート１３を得た（図６（ｄ））。
【００６４】
上記正極活物質層１５を上に向けた正極シート１１上に、ポリマー電解質層１２を下に向けた複数枚の負極シート１３を、所定の間隔をあけて配置して熱圧着することにより積層体２４を作製した（図８）。この積層体２４を、図３に示すように、帯状の正極シート１１のうち負極シート１３の配置されていない部分を、交互にジグザグに折曲げて折畳んだ。これにより正極シート１１は幅及び長さがそれぞれ１１ｃｍ及び１２ｃｍである折畳み面積を有するように折畳まれ、この正極シート１１の間に、幅及び長さがそれぞれ１０ｃｍ及び１２ｃｍである１０枚の負極シート１３がポリマー電解質層１２を介して挟持された。更に正極集電体箔１４の一方の側縁１４ａに正極端子１６を接続し、負極集電体箔１７の一方の側縁１７ａに負極端子１９を接続した後に、これらの端子１６，１９が突出するように上記積層体２４を一対のパッケージシート２８，２８により密封した。このリチウムイオンポリマー二次電池１０を実施例１とした。
【００６５】
＜比較例１＞
ポリマー電解質層が、負極集電体箔の表面の一部及び負極活物質層の全表面を被覆する負極側第１電解質層負極側第１電解質層のみからなること以外を、実施例１と同様にしてリチウムイオンポリマー二次電池を作製した。この電池を比較例１とした。
【００６６】
＜比較試験１及び評価＞
実施例１及び比較例１のリチウムイオンポリマー二次電池の容量保持率のサイクル特性を充放電試験機により測定した。この結果を図２２に示す。
図２２から明らかなように、実施例１におけるリチウムイオンポリマー二次電池のサイクル特性における勾配は、比較例１における勾配に比較して緩やかであり、実施例１の容量保持率のサイクル特性は比較例１の容量保持率のサイクル特性より向上していることが判った。これは、実施例１では負極集電体箔の他方の側縁と負極集電体の他方の側縁との間に剥離が発生しなかったためであると考えられる。
【００６７】
【発明の効果】
以上述べたように、本発明によれば、ポリマー電解質層を、負極側第１電解質層及び負極側第２電解質層により構成し、負極側第１電解質層を負極シートの表面に形成し、更に負極側第２電解質層を負極側第１電解質層に連設しかつ負極シートの他方の側縁の端面に形成したので、負極シートの他方の側縁がポリマー電解質層にて被覆され、負極集電体箔及び負極活物質層の剥離を抑制できる。この結果、電池容量の低下を防止できるので、電池のサイクル特性を向上できるとともに、電池の放電容量及び出力特性を向上できる。また負極活物質層の他方の側縁もリチウムイオンの吸蔵及び放出に寄与するので、電池の放電容量及び出力特性を向上できるとともに、負極シートの他方の側縁が露出しなくなるので、積層体の折畳みによる正極シート及び負極シートの接触を阻止でき、電池内での短絡を防止できる。
【００６８】
またポリマー電解質層を、正極側第１電解質層及び正極側第２電解質層により構成し、正極側第１電解質層を正極シートの表面に形成し、更に正極側第２電解質層を正極側第１電解質層に連設しかつ正極シートの他方の側縁の端面に形成すれば、正極シートの他方の側縁がポリマー電解質層にて被覆され、正極集電体箔及び正極活物質層の剥離を抑制できるので、上記と同様の効果が得られる。また正極活物質層の他方の側縁もリチウムイオンの吸蔵及び放出に寄与するので、電池の放電容量及び出力特性を向上できるとともに、正極シートの他方の側縁が露出しなくなるので、積層体の折畳みによる正極シート及び負極シートの接触を阻止でき、電池内での短絡を防止できる。
【００６９】
またポリマー電解質層を、上記負極側第１電解質層、負極側第２電解質層、正極側第１電解質層及び正極側第２電解質層により構成すれば、負極シートの他方の側縁及び正極シートの他方の側縁がポリマー電解質層にて被覆され、負極集電体箔及び負極活物質層の剥離と、正極集電体箔及び正極活物質層の剥離とを抑制できるので、電池容量の低下を防止でき、負極シートの他方の側縁又は正極シートの他方の側縁のいずれか一方をポリマー電解質層にて被覆したものより、電池のサイクル特性を向上できるとともに、電池の放電容量及び出力特性を向上できる。また負極活物質層の他方の側縁もリチウムイオンの吸蔵及び放出に寄与するので、負極シートの他方の側縁又は正極シートの他方の側縁のいずれか一方をポリマー電解質層にて被覆したものより、電池の放電容量及び出力特性を向上できるとともに、負極シートの他方の側縁及び正極シートの他方の側縁が露出しなくなるので、積層体の折畳みによる正極シート及び負極シートの接触を確実に阻止でき、電池内での短絡を確実に防止できる。
【００７０】
また負極側第２電解質層に連設された負極側第３電解質層を負極シートの裏面に所定の幅及び厚さに形成すれば、負極シートの他方の側縁の上面が負極側第１電解質層にて被覆され、他方の側縁の端面が負極側第２電解質層にて被覆され、更に他方の側縁の裏面が負極側第３電解質層にて被覆されるので、負極シートの他方の側縁が全く露出しなくなり、正極シートの折畳みによる正極シート及び負極シートの接触を確実に阻止できる。
【００７１】
更に正極側第２電解質層に連設された正極側第３電解質層を正極シートの裏面に所定の幅及び厚さに形成すれば、正極シートの他方の側縁の上面が正極側第１電解質層にて被覆され、他方の側縁の端面が正極側第２電解質層にて被覆され、他方の側縁の裏面が正極側第３電解質層にて被覆されるので、正極シートの他方の側縁が全く露出しなくなり、正極シートの折畳みによる正極シート及び負極シートの接触を確実に阻止できる。
【図面の簡単な説明】
【図１】本発明第１実施形態のリチウムイオンポリマー二次電池を示す図２のＡ−Ａ線断面図。
【図２】図１のＢ−Ｂ線断面図。
【図３】その電池の密封直前の状態を示す分解斜視図。
【図４】ドクタブレード法により負極集電体箔に電解質スラリーを塗布している状態を示す要部斜視図。
【図５】図４のＣ−Ｃ線断面図。
【図６】負極シートの製造工程を示す図。
【図７】正極シートの製造工程を示す図。
【図８】負極シートを正極シートに熱圧着する直前の状態を示す斜視図。
【図９】本発明第２実施形態を示す図１０のＤ−Ｄ線断面図。
【図１０】図９のＥ−Ｅ線断面図。
【図１１】負極シートの製造工程を示す図。
【図１２】正極シートの製造工程を示す図。
【図１３】負極シートを正極シートに熱圧着する直前の状態を示す斜視図。
【図１４】本発明第３実施形態を示す図１５のＦ−Ｆ線断面図。
【図１５】図１４のＧ−Ｇ線断面図。
【図１６】負極シートの製造工程を示す図。
【図１７】正極シートの製造工程を示す図。
【図１８】負極シートを正極シートに熱圧着する直前の状態を示す斜視図。
【図１９】本発明第４実施形態を示す図１に対応する断面図。
【図２０】本発明第５実施形態を示す図９に対応する断面図。
【図２１】本発明第６実施形態を示す図１４に対応する断面図。
【図２２】実施例１及び比較例１のリチウムイオンポリマー二次電池の容量保持率のサイクル特性を示す図。
【符号の説明】
１０，４０，５０，６０，７０，８０ リチウムイオンポリマー二次電池
１１ 正極シート
１１ａ 正極シートの一方の側縁
１１ｂ 正極シートの他方の側縁
１２，４２，５２，６２，７２，８２ ポリマー電解質層
１２ａ 負極側第１電解質層
１２ｂ 負極側第２電解質層
１２ｃ 負極側第３電解質層
１３ 負極シート
１３ａ 負極シートの一方の側縁
１３ｂ 負極シートの他方の側縁
１４ 正極集電体箔
１４ａ 正極集電体箔の一方の側縁
１４ｂ 正極集電体箔の他方の側縁
１５ 正極活物質層
１５ａ 正極活物質層の一方の側縁
１５ｂ 正極活物質層の他方の側縁
１６ 正極端子
１７ 負極集電体箔
１７ａ 負極集電体箔の一方の側縁
１７ｂ 負極集電体箔の他方の側縁
１８ 負極活物質層
１８ａ 負極活物質層の一方の側縁
１８ｂ 負極活物質層の他方の側縁
１９ 負極端子
２１ 電解質スラリー
２２ 塗布機用タンク
２２ａ 扁平ノズル
４２ａ 正極側第１電解質層
４２ｂ 正極側第２電解質層
４２ｃ 正極側第３電解質層[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a lithium ion polymer secondary battery in which a positive electrode sheet and a negative electrode sheet are laminated with a polymer electrolyte layer interposed.
[0002]
[Prior art]
Conventionally, as a secondary battery of this type, a negative electrode is formed by forming a negative electrode active material layer on one surface of a strip-shaped negative electrode current collector, and forming a positive electrode active material layer on one surface of a strip-shaped positive electrode current collector. A solid electrolyte battery in which a stacked electrode body is formed by stacking the negative electrode and the positive electrode with a solid electrolyte layer interposed therebetween, and a lead wire is further attached to the negative electrode and the positive electrode, respectively. Is disclosed (for example, see Patent Document 1). In this solid electrolyte battery, the negative electrode and the positive electrode are folded in a state where the negative electrode active material layer side and the positive electrode active material layer side face each other, and a gel electrolyte layer is interposed between the negative electrode and the positive electrode. It is formed by this. The longitudinal end of the negative electrode or the positive electrode is covered with an insulating member larger than the width of the negative electrode or the positive electrode.
[0003]
In the solid electrolyte battery configured as described above, the longitudinal end of the negative electrode or the positive electrode is covered with an insulating member that is larger than the width of the negative electrode or the positive electrode. Contact near the end in the direction is prevented, and insulation is maintained. As a result, it is possible to prevent an electric short circuit inside the battery at the time of manufacturing the battery.
[0004]
[Patent Document 1]
JP 2000-173657 A
[0005]
[Problems to be solved by the invention]
However, in the solid electrolyte battery disclosed in Patent Document 1, at the widthwise ends of the negative electrode and the positive electrode, between the negative electrode current collector foil and the negative electrode active material layer, or between the positive electrode current collector foil and the positive electrode active material layer. Peeling may occur, which causes a problem that the cycle characteristics of the secondary battery deteriorate.
Further, in the solid electrolyte battery disclosed in Patent Document 1, since the side surfaces of the negative electrode current collector foil and the positive electrode current collector foil are exposed, when the laminated electrode body is folded, the negative electrode current collector foil and The exposed side surfaces of the positive electrode current collector foil may come into contact with each other to cause a short circuit.
[0006]
A first object of the present invention is to cover the side edges of the current collector foil and the active material layer with a polymer electrolyte layer, thereby suppressing peeling of the current collector foil and the active material layer, thereby reducing the battery capacity. An object of the present invention is to provide a lithium-ion polymer secondary battery that can prevent a decrease and improve cycle characteristics, discharge capacity, and output characteristics.
A second object of the present invention is to provide a lithium ion polymer secondary battery that can prevent a short circuit between a positive electrode sheet and a negative electrode sheet by covering a side edge of a current collector foil with a polymer electrolyte layer. .
[0007]
[Means for Solving the Problems]
As shown in FIGS. 1 and 2, the invention according to claim 1 has a positive electrode active material layer 15 formed on the surface of a band-shaped positive electrode current collector foil 14 and is folded once or twice or more. The negative electrode active material layer 18 is formed on the surface of a positive electrode sheet 11 in which the positive electrode terminal 16 is connected to one side edge 11a and a negative electrode current collector foil 17 having an area corresponding to the folded area of the positive electrode sheet 11. This is an improvement of a lithium ion polymer secondary battery including a negative electrode sheet 13 sandwiched between a folded positive electrode sheet 11 with a polymer electrolyte layer 12 interposed therebetween and having a negative electrode terminal 19 connected to one side edge 13a. .
The characteristic configuration is such that the polymer electrolyte layer 12 has a negative electrode side first electrolyte layer 12 a formed on the surface of the negative electrode sheet 13, and the other side edge 13 b of the negative electrode sheet 13 which is connected to the negative electrode side first electrolyte layer 12 a. And the negative-electrode-side second electrolyte layer 12b formed on the end face.
[0008]
In the lithium ion polymer secondary battery described in claim 1, the other side edge 13 b of the negative electrode sheet 13 is covered with the polymer electrolyte layer 12 to form the negative electrode current collector foil 17 and the negative electrode active material layer 18. Since peeling can be suppressed, a decrease in battery capacity can be prevented, and the cycle characteristics of the battery 10 can be improved. Further, the other side edge 18b of the negative electrode active material layer 18 also contributes to occlusion and release of lithium ions, so that the discharge capacity and output characteristics of the battery 10 can be improved. Further, by covering the other side edge 13b of the negative electrode sheet 13 with the polymer electrolyte layer 12, the other side edge 13b of the negative electrode sheet 13 is not exposed, so that the positive electrode sheet 11 and the negative electrode sheet 13 Contact can be prevented.
[0009]
In the invention according to claim 2, as shown in FIGS. 9 and 10, the polymer electrolyte layer 42 is formed on the positive electrode side first electrolyte layer 42a formed on the surface of the positive electrode sheet 11 and the positive electrode side first electrolyte layer 42a. And a positive electrode side second electrolyte layer 42b formed on the end face of the other side edge 11b of the positive electrode sheet 11 which is continuously provided.
In the lithium ion polymer secondary battery according to the second aspect, by covering the other side edge 11b of the positive electrode sheet 11 with the polymer electrolyte layer 42, the positive electrode current collector foil 14 and the positive electrode active material layer 15 Since peeling can be suppressed, a decrease in battery capacity can be prevented, and the cycle characteristics of the battery 40 can be improved. Further, the other side edge 15b of the positive electrode active material layer 15 also contributes to occlusion and release of lithium ions, so that the discharge capacity and output characteristics of the battery 40 can be improved. Further, by covering the other side edge 11b of the positive electrode sheet 11 with the polymer electrolyte layer 42, the other side edge 11b of the positive electrode sheet 11 is not exposed. Contact can be prevented.
[0010]
In the invention according to claim 3, as shown in FIGS. 14 and 15, the polymer electrolyte layer 52 is formed on the negative electrode side first electrolyte layer 12a and the negative electrode side first electrolyte layer 12a formed on the surface of the negative electrode sheet 13. The negative electrode side second electrolyte layer 12b formed on the end face of the other side edge 13b of the negative electrode sheet 13 that is continuously provided, the positive electrode side first electrolyte layer 42a formed on the surface of the positive electrode sheet 11, and the positive electrode side first electrolyte And a positive electrode-side second electrolyte layer 42b formed on the end face of the other side edge 11b of the positive electrode sheet 11 and connected to the layer 42a.
In the lithium ion polymer secondary battery according to the third aspect, the other side edge 13 b of the negative electrode sheet 13 and the other side edge 11 b of the positive electrode sheet 11 are covered with the polymer electrolyte layer 52, thereby collecting the negative electrode current. Since the peeling of the body foil 17 and the negative electrode active material layer 18 and the peeling of the positive electrode current collector foil 14 and the positive electrode active material layer 15 can be suppressed, a reduction in battery capacity can be prevented more reliably than in the above-mentioned claim 1 or 2, The cycle characteristics of the battery 50 can be improved as compared with the first or second aspect. Further, the other side edge 18b of the negative electrode active material layer 18 and the other side edge 15b of the positive electrode active material layer 15 also contribute to occlusion and release of lithium ions. 2 can be improved. Further, the other side edge 13b of the negative electrode sheet 13 and the other side edge 11b of the positive electrode sheet 11 are covered with a polymer electrolyte layer 52, so that the other side edge 13b of the negative electrode sheet 13 and the other side edge of the positive electrode sheet 11 are covered. Since the exposed portion 11b is not exposed, the contact between the positive electrode sheet 11 and the negative electrode sheet 13 due to the folding of the positive electrode sheet 11 can be more reliably prevented than in the first or second aspect.
[0011]
The invention according to claim 4 is the invention according to claim 1 or 3, further comprising a predetermined surface provided on the back surface of the negative electrode sheet 13 which is connected to the negative electrode side second electrolyte layer 12b as shown in FIGS. A negative electrode-side third electrolyte layer 12c formed to have a width and a thickness is further provided.
In the lithium ion polymer secondary battery according to the fourth aspect, the upper surface of the other side edge 13b of the negative electrode sheet 13 is covered with the negative electrode side first electrolyte layer 12a, and the end surface of the other side edge 13b is connected to the negative electrode side. Since the second electrolyte layer 12b is covered and the back surface of the other side edge 13b is covered with the negative third electrolyte layer 12c, the other side edge 13b of the negative electrode sheet 13 is not exposed at all and the positive electrode sheet 11 Can be reliably prevented from contacting the positive electrode sheet 11 and the negative electrode sheet 13 due to folding.
[0012]
The invention according to claim 5 is the invention according to claim 2 or 3, further comprising, as shown in FIGS. 9 and 10, a predetermined surface provided on the back surface of the positive electrode sheet 11 and connected to the second electrolyte layer 42 b on the positive electrode side. A positive electrode side third electrolyte layer 42c having a width and a thickness is further provided.
In the lithium ion polymer secondary battery according to the fifth aspect, the upper surface of the other side edge 11b of the positive electrode sheet 11 is covered with the first electrolyte layer 42a on the positive electrode side, and the end surface of the other side edge 11b is connected to the positive electrode side. Since it is covered with the second electrolyte layer 42b and the back surface of the other side edge 11b is covered with the positive third electrolyte layer 42c, the other side edge 11b of the positive electrode sheet 11 is not exposed at all. Can be reliably prevented from contacting the positive electrode sheet 11 and the negative electrode sheet 13 due to folding.
[0013]
As shown in FIGS. 4 to 6, the invention according to claim 6 is configured such that one side edge is formed on the surface of the strip-shaped negative electrode current collector foil 17 from one side edge 17 a of the negative electrode current collector foil 17. A step of forming a strip-shaped negative electrode active material layer 18 by being positioned inward by the width and making the other side edge coincide with the other side edge 17b of the negative electrode current collector foil 17, and a coating machine tank having a flat nozzle 22a A step of storing the electrolyte slurry 21 having a viscosity of 0.5 to 45 P in the anode 22, and connecting one end of the flat nozzle 22 a to the negative electrode current collector on the outside in the width direction by a predetermined width from one side edge 18 a of the negative electrode active material layer 18. With the other end of the flat nozzle 22a positioned on the foil 17 and the other end 18b of the negative electrode active material layer 18 positioned outside the width direction by a predetermined width, the negative electrode current collector foil 17 is moved in the longitudinal direction. While moving the electrolyte slurry 2 from the flat nozzle 22a, By discharging the electrolyte slurry 21, a part of the surface of the negative electrode current collector foil 17, the entire surface of the negative electrode active material layer 18, the end face of the other side edge 17 b of the negative electrode current collector foil 17, and the negative electrode active material layer 18 is continuously applied to the end face of the other side edge 18b of the negative electrode 18 and the back surface of the other side edge 17b of the negative electrode current collector foil 17, and the continuously applied electrolyte slurry 21 is dried. And a negative electrode-side first electrolyte layer 12a covering the entire surface of the negative electrode active material layer 18, the end surface of the other side edge 17b of the negative electrode current collector foil 17, and the other side of the negative electrode active material layer 18. The polymer electrolyte layer 12 composed of the negative electrode side second electrolyte layer 12b covering the end face of the edge 18b and the negative electrode side third electrolyte layer 12c covering the back surface of the other side edge 17b of the negative electrode current collector foil 17 is formed. Process and the strip-shaped negative electrode current collector foil 17 With material layer 18 and the polymer electrolyte layer 12 is a method for producing a lithium polymer battery and a step of cutting to length.
When the lithium ion polymer secondary battery is manufactured by the method described in claim 6, the lithium ion polymer secondary battery described in claim 1 can be obtained.
[0014]
As shown in FIG. 12, the invention according to claim 7 has one side edge on the surface of the belt-shaped positive electrode current collector foil 14 inside the one side edge 14a of the positive electrode current collector foil 14 by a predetermined width. To form a strip-shaped positive electrode active material layer 15 with the other side edge coinciding with the other side edge 14b of the positive electrode current collector foil 14; A step of storing an electrolyte slurry of 0.5 to 45 P, and positioning one end of the flat nozzle on the positive electrode current collector foil 14 on the outside in the width direction by a predetermined width from one side edge 15 a of the positive electrode active material layer 15; While moving the positive electrode current collector foil 14 in the longitudinal direction in a state where the other end of the flat nozzle is located outside the other side edge 15b of the positive electrode active material layer 15 by a predetermined width in the width direction, the electrolyte is passed through the flat nozzle. By discharging the slurry, the electrolyte slurry is A part of the surface of the positive electrode current collector foil 14, the entire surface of the positive electrode active material layer 15, the end surface of the other side edge 14b of the positive electrode current collector foil 14, and the end surface of the other side edge 15b of the positive electrode active material layer 15 The step of continuously applying the back surface of the other side edge 14b of the positive electrode current collector foil 14 and the drying of the continuously applied electrolyte slurry form a part of the surface of the positive electrode current collector foil 14 and the positive electrode active material layer 15 The positive electrode side first electrolyte layer 42a covering the entire surface of the positive electrode current collector foil 14, and the positive electrode side second electrode surface covering the other side edge 15b of the positive electrode active material layer 15 Forming a polymer electrolyte layer 42 comprising an electrolyte layer 42b and a cathode-side third electrolyte layer 42c covering the back surface of the other side edge 14b of the cathode current collector foil 14. It is a manufacturing method.
When the lithium ion polymer secondary battery is manufactured by the method described in claim 7, the lithium ion polymer secondary battery described in claim 2 can be obtained.
[0015]
As shown in FIG. 19, the invention according to claim 8 has a configuration in which one side edge is provided on the surface of the strip-shaped negative electrode current collector foil 17 by a predetermined width from one side edge 17a of the negative electrode current collector foil 17. To form a strip-shaped negative electrode active material layer 18 with the other side edge coinciding with the other side edge 17b of the negative electrode current collector foil 17; A step of storing an electrolyte slurry of ８０80 P, and positioning one end of the flat nozzle on the negative electrode current collector foil 17 on the outer side in the width direction by a predetermined width from one side edge 18 a of the negative electrode active material layer 18. While moving the negative electrode current collector foil 17 in the longitudinal direction with the other end of the negative electrode active material layer 18 positioned outside the other side edge 18b of the negative electrode active material layer 18 by a predetermined width in the width direction, the electrolyte slurry is discharged from the flat nozzle. By discharging, the electrolyte slurry is negatively charged. Part of the surface of the current collector foil 17, the entire surface of the negative electrode active material layer 18, the end face of the other side edge 17 b of the negative electrode current collector foil 17, and the end face of the other side edge 18 b of the negative electrode active material layer 18 A negative electrode side first electrolyte layer 12a that covers a part of the surface of the negative electrode current collector foil 17 and the entire surface of the negative electrode active material layer 18 by applying and drying the continuously applied electrolyte slurry; Forming a polymer electrolyte layer 62 comprising an end face of the other side edge 17b of the current collector foil 17 and a negative electrode side second electrolyte layer 12b covering the end face of the other side edge 18b of the negative electrode active material layer 18; Cutting the strip-shaped negative electrode current collector foil 17 into a predetermined length together with the negative electrode active material layer 18 and the polymer electrolyte layer 62.
In the method for manufacturing a lithium ion polymer secondary battery according to claim 8, the polymer electrolyte layer 62 composed of the negative electrode first electrolyte layer 12a and the negative electrode second electrolyte layer 12b can be used even if an electrolyte slurry having a relatively high viscosity is used. Can be formed on the negative electrode sheet 13.
[0016]
According to the ninth aspect of the present invention, as shown in FIG. 20, one side edge of the surface of the belt-shaped positive electrode current collector foil 14 is inward from the one side edge 14 b of the positive electrode current collector foil 14 by a predetermined width. To form a strip-shaped positive electrode active material layer 15 with the other side edge coinciding with the other side edge 14b of the positive electrode current collector foil 14; A step of storing an electrolyte slurry of ８０80 P, and positioning one end of the flat nozzle on the positive electrode current collector foil 14 on the outside in the width direction by a predetermined width from one side edge 15 a of the positive electrode active material layer 15, and While moving the positive electrode current collector foil 14 in the longitudinal direction with the other end of the positive electrode active material layer 15 positioned outside the other side edge 15b of the positive electrode active material layer 15 by a predetermined width in the width direction, the electrolyte slurry is discharged from the flat nozzle. By discharging, the electrolyte slurry is corrected A portion of the surface of the current collector foil 14, the entire surface of the positive electrode active material layer 15, the end face of the other side edge 14b of the positive electrode current collector foil 14, and the end face of the other side edge 15b of the positive electrode active material layer 15 are continuous. A positive electrode side first electrolyte layer 42a that covers a part of the surface of the positive electrode current collector foil 14 and the entire surface of the positive electrode active material layer 15 by applying and drying the continuously applied electrolyte slurry; Forming a polymer electrolyte layer 72 consisting of an end face of the other side edge 14b of the current collector foil 14 and a positive electrode side second electrolyte layer 42b covering the end face of the other side edge 15b of the positive electrode active material layer 15. And a method for producing a lithium ion polymer secondary battery.
In the method of manufacturing a lithium ion polymer secondary battery according to the ninth aspect, the polymer electrolyte layer 72 composed of the positive electrode first electrolyte layer 42a and the positive electrode second electrolyte layer 42b can be used even when an electrolyte slurry having a relatively high viscosity is used. Can be formed on the positive electrode sheet 11.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, a first embodiment of the present invention will be described with reference to the drawings.
As shown in FIGS. 1 to 3, a lithium ion polymer secondary battery 10 includes a belt-shaped positive electrode sheet 11 that is folded once or twice or more, and a folded positive electrode sheet 11. One or two or more negative electrode sheets 13 sandwiched between polymer electrolyte layers 12 are provided. The positive electrode sheet 11 has a band-shaped positive electrode current collector foil 14 and a band-shaped positive electrode active material layer 15 formed on the surface of the positive electrode current collector foil 14. The width of the positive electrode active material layer 15 is formed smaller than the width of the positive electrode current collector foil 14 (FIGS. 1 and 3). That is, in the positive electrode active material layer 15, one side edge 15a is located inside the one side edge 14a of the positive electrode current collector foil 14 by a predetermined width in the width direction, and the other side edge 15b is It is formed so as to coincide with the other side edge 14 b of the body foil 14. A positive electrode terminal 16 is connected to one side edge 11a of the positive electrode sheet 11, that is, one side edge 14a of the positive electrode current collector foil 14 on which the positive electrode active material layer 15 is not formed.
[0018]
The negative electrode sheet 13 has a negative electrode current collector foil 17 and a negative electrode active material layer 18 formed on the surface of the negative electrode current collector foil 17, and has an area corresponding to the folded area of the positive electrode current collector foil 14. Have. The width of the negative electrode active material layer 18 is formed smaller than the width of the negative electrode current collector foil 17 (FIGS. 1 and 3). That is, in the negative electrode active material layer 18, one side edge 18 a is located inside the one side edge 17 a of the negative electrode current collector foil 17 by a predetermined width in the width direction, and the other side edge 18 b is connected to the negative electrode current collector foil 17. It is formed so as to coincide with the other side edge 17 b of the body foil 17. Further, a negative electrode terminal 19 is connected to one side edge 13 a of the negative electrode sheet 13, that is, one side edge 17 a of the negative electrode current collector foil 17 on which the negative electrode active material layer 18 is not formed. Note that one side edge 15a of the positive electrode active material layer 15 matches the other side edge 13b of the negative electrode sheet 13, and one side edge 18a of the negative electrode active material layer 18 and the other side edge 11b of the positive electrode sheet 11 And the positive electrode sheet 11 and the negative electrode sheet 13 are laminated. In other words, one side edge 14a of the positive electrode current collector foil 14 protrudes from the other side edge 17b of the negative electrode current collector foil 17, and one side edge 17a of the negative electrode current collector foil 17 is The positive electrode sheet 11 and the negative electrode sheet 13 are stacked so as to protrude from the other side edge 14b of 14.
[0019]
On the other hand, the polymer electrolyte layer 12 is formed from the surface of the negative electrode sheet 13 to the other side edge 13b. In this embodiment, the polymer electrolyte layer 12 includes a negative electrode-side first electrolyte layer 12 a formed on the surface of the negative electrode sheet 13, and the other side edge 13 b of the negative electrode sheet 13 that is connected to the negative electrode side first electrolyte layer 12 a. A negative-electrode-side second electrolyte layer 12b formed on the end surface of the negative electrode-side second electrolyte layer 12b, and a negative-electrode-side third electrolyte layer 12c formed to have a predetermined width and thickness on the back surface of the negative electrode sheet 13 and connected to the negative electrode-side second electrolyte layer 12b. Having. The negative electrode-side first electrolyte layer 12a has one side edge located on the negative electrode current collector foil 17 that is outside the one side edge 18a of the negative electrode active material layer 18 by a predetermined width in the width direction, and has the other side edge. The edge is formed so as to match the other side edge 18 b of the negative electrode active material layer 18, that is, to cover the surface of the negative electrode active material layer 18 and the end face of one side edge 18 a. The negative electrode-side second electrolyte layer 12b is formed so as to cover the end face of the other side edge 17b of the negative electrode current collector foil 17 and the end face of the other side edge 18b of the negative electrode active material layer 18.
[0020]
Further, the negative electrode-side third electrolyte layer 12c has a width of 0.5 to 20 mm, preferably 3 to 12 mm, and a thickness of 2 to 100 μm, preferably, on the back surface of the other side edge 17 b of the negative electrode current collector foil 17. It is formed to have a thickness of 10 to 60 μm. The reason why the width of the negative electrode-side third electrolyte layer 12c is limited to the range of 0.5 to 20 mm is that when the width is less than 0.5 mm, the positive electrode sheet 11 and the negative electrode This is because the sheet 13 may be short-circuited, and if it exceeds 20 mm, the energy density may be reduced, and the folding deviation of the positive electrode sheet 11 with the negative electrode sheet 13 interposed therebetween may not exceed 20 mm. . Also, the reason why the thickness of the negative electrode side third electrolyte layer 12c is limited to the range of 2 to 100 μm is that when the thickness is less than 2 μm, the material of the negative electrode side third electrolyte layer 12c is weak, The negative electrode sheet 13 may be short-circuited to the positive electrode sheet 11. If the thickness exceeds 100 μm, the negative electrode sheet 13 on which the third negative electrode-side electrolyte layer 12 c is formed when the positive electrode sheet 11 with the negative electrode sheet 13 interposed therebetween is folded. This is because only the end of the positive electrode sheet becomes thick, and the positive electrode sheet in the vicinity of the outermost part is broken during vacuum packing, and cannot be accommodated in the container without any gap.
[0021]
The positive electrode current collector foil 14 may be an Al foil, and the active material of the positive electrode active material layer 15 may be LiCoO 2. Two Is mentioned. The negative electrode current collector foil 17 includes a Cu foil, and the negative electrode active material layer 18 includes a carbon-based active material. Examples of the polymer of the polymer electrolyte layer 12 include polyethylene oxide and polyvinylidene fluoride, and examples of the electrolyte of the polymer electrolyte layer 12 include a mixed solution containing ethylene carbonate, propylene carbonate, γ-butyrolactone, and the like.
[0022]
A method for manufacturing the lithium ion polymer secondary battery 10 configured as described above will be described with reference to FIGS.
(1) Production of positive electrode sheet 11
First, the active material contained in the positive electrode active material layer 15 is dispersed and mixed in an N-methylpyrrolidone solution or the like to prepare a positive electrode active material slurry. Next, the slurry is continuously applied to the upper surface of the belt-shaped positive electrode current collector foil 14 by a doctor blade method, a screen printing method, or the like, and dried (FIG. 7B). At this time, one side edge 15a of the positive electrode active material layer 15 is shifted inward in the width direction by a predetermined width from one side edge 14a of the positive electrode current collector foil 14, and the other side edge 15b of the positive electrode active material layer 15 is The positive electrode active material layer 15 is formed in a strip shape on the upper surface of the positive electrode current collector foil 14 in a state of being aligned with the other side edge 14a of the positive electrode current collector foil 14. Thus, the positive electrode sheet 11 is manufactured.
[0023]
{Circle around (2)} Preparation of strip-shaped negative electrode sheet 13
First, the active material contained in the negative electrode active material layer 18 is dispersed and mixed in an N-methylpyrrolidone solution or the like to prepare a negative electrode active material slurry. Next, this slurry is continuously applied to the upper surface of the strip-shaped negative electrode current collector foil 17 by a doctor blade method, a screen printing method, or the like, and dried (FIG. 6B). At this time, one side edge 18a of the negative electrode active material layer 18 is shifted inward in the width direction by a predetermined width from one side edge 17a of the negative electrode current collector foil 17, and the other side edge 18b of the negative electrode active material layer 18 is The negative electrode active material layer 18 is formed in a strip shape on the upper surface of the negative electrode current collector foil 17 in a state of being aligned with the other side edge 17 b of the negative electrode current collector foil 17. Thereby, a strip-shaped negative electrode sheet 13 is produced.
[0024]
{Circle around (3)} Formation of polymer electrolyte layer 12 on negative electrode sheet 13
First, an electrolyte slurry 21 (FIGS. 4 and 5) prepared by mixing a polymer, an electrolytic solution and a lithium metal salt and having a viscosity of 0.5 to 45 P (poise) is prepared. Next, this slurry is continuously applied to the surfaces and side edges of the strip-shaped negative electrode current collector foil 17 and the negative electrode active material layer 18 by a doctor blade method. At this time, as shown in FIGS. 4 and 5, the electrolyte slurry 21 is stored in a coating machine tank 22 having a flat nozzle 22 a, and one end of the flat nozzle 22 a is a predetermined distance from one side edge 18 a of the negative electrode active material layer 18. The other end of the flat nozzle 22a is positioned on the widthwise outer roller 23 by a predetermined width from the other side edge 18b of the negative electrode active material layer 18 by positioning the other end of the flat nozzle 22a on the outer side in the width direction by the width. In this state, the electrolyte slurry 21 is continuously discharged from the flat nozzle 22a while moving the negative electrode current collector foil 17 in the longitudinal direction. As a result, the electrolyte slurry 21 forms part of the surface of the negative electrode current collector foil 17, the entire surface of the negative electrode active material layer 18, the end surface of the other side edge 17b of the negative electrode current collector foil 17, and the other of the negative electrode active material layer 18. Is continuously applied to the end surface of the side edge 18b of the negative electrode current collector foil 17 and the back surface of the other side edge 17b of the negative electrode current collector foil 17. Here, the reason that the electrolyte slurry 21 is also applied to the back surface of the other side edge 17b of the negative electrode current collector foil 17 is that the slurry 21 has a relatively low viscosity of 0.5 to 45P, This is because it also goes around the back surface of the other side edge 17b of the current collector foil 17. Reference numeral 23a in FIG. 5 denotes a scraper for scraping off the slurry 21 attached to the outer peripheral surface of the roller 23.
[0025]
Next, by drying the continuously applied electrolyte slurry 21, the negative electrode side first electrolyte layer 12 a covering a part of the surface of the negative electrode current collector foil 17 and the entire surface of the negative electrode active material layer 18, A negative-electrode-side second electrolyte layer 12b covering the end face of the other side edge 17b of the current collector foil 17 and the end face of the other side edge 18b of the negative electrode active material layer 18; and the other side edge 17b of the negative electrode current collector foil 17 A polymer electrolyte layer 12 composed of a negative electrode-side third electrolyte layer 12c that covers the back surface of is formed (FIG. 6C). Further, the strip-shaped negative electrode sheet 13 is cut into a predetermined length together with the strip-shaped polymer electrolyte layer 12, whereby a final-shaped negative electrode sheet 13 having the polymer electrolyte layer 12 is produced (FIG. 6D).
[0026]
(4) Thermocompression bonding of the positive electrode sheet 11 and the negative electrode sheet 13
First, on the positive electrode sheet 11 with the belt-shaped positive electrode active material layer 15 facing upward, a plurality of negative electrode sheets 13 with the polymer electrolyte layer 21 facing downward are arranged at predetermined intervals, thereby producing a laminate 24. (FIG. 8). Next, the laminated body 24 is inserted between a pair of rollers 25, 25 heated to a predetermined temperature and rotating in the direction of the solid arrow, from the direction shown by the broken arrow. Thereby, the positive electrode sheet 11 and the negative electrode sheet 13 are thermocompression-bonded with the polymer electrolyte layer 12 interposed therebetween. Note that one side edge 14a of the band-shaped positive electrode current collector foil 14 protrudes from the other side edge 13b of the plurality of negative electrode sheets 13, and one side edge 17a of the plurality of negative electrode current collector foils 17 has a band shape. The negative electrode sheet 13 is arranged on the positive electrode sheet 11 so as to protrude from the other side edge 11b of the positive electrode sheet 11.
[0027]
(5) Folding of the laminate 24
The laminate 24 that has been thermocompression-bonded is folded by folding. That is, as shown in FIG. 3, portions of the belt-shaped positive electrode sheet 11 where the negative electrode sheet 13 is not arranged are alternately zigzag and folded. At this time, one side edge 14a of the band-shaped positive electrode current collector foil 14 is laminated so as to protrude from the other side edge 17b of the plurality of negative electrode current collector foils 17, and One of the side edges 17a is laminated so as to protrude from the other side edge 14b of the belt-shaped positive electrode current collector foil 14. In the stacked body 24 thus folded, a plurality of negative electrode sheets 13 having an area corresponding to the folded area are sandwiched between the folded positive electrode sheets 11 via the polymer electrolyte layer 12. You. One side edge 14a of the positive electrode current collector foil 14 protrudes from the other side edge 13b of the plurality of negative electrode sheets 13 in a zigzag manner, and a stopper 26 penetrates this protruding portion. At the same time, one end of the positive electrode terminal 16 is fixed to the protruding portion by the stopper 26 (FIGS. 1 and 3). Also, one side edge 17a of the plurality of negative electrode current collector foils 17 protrudes from the other side edge 11b of the positive electrode sheet 11, and a stopper 27 penetrates these protruding portions. Thereby, one end of the negative electrode terminal 19 is fixed to the protruding portion.
[0028]
(6) Sealing of the folded laminate 24
The folded body 24 having the positive electrode terminal 16 and the negative electrode terminal 19 is hermetically sealed by a pair of package sheets 28, 28 made of aluminum foil laminated with polypropylene (FIGS. 1 to 3). Specifically, the folded laminate 24 having the positive terminal 16 and the negative terminal 19 is placed in a vacuum atmosphere, and the other end of the positive terminal 16 and the other end of the negative terminal 19 are outside the package sheets 28, 28. In a state where the package sheets 28 and 28 are projected, the periphery of the pair of package sheets 28 is sealed by thermocompression bonding. The lithium-ion polymer secondary battery 10 manufactured as described above has a desired power by using the other end of the positive electrode terminal 16 and the other end of the negative electrode terminal 19 protruding from the package sheets 28, 28 as terminals of the battery 10. Can be obtained.
[0029]
In the lithium ion polymer secondary battery 10 thus manufactured, the other side edge 13b of the negative electrode sheet 13 is covered with the polymer electrolyte layer 12, that is, the negative electrode is formed on the other side edge of the negative electrode side first electrolyte layer 12a. The upper surface of the other side edge 18b of the active material layer 18 is covered, and the end surface of the other side edge 17b of the negative electrode current collector foil 17 and the other side edge of the negative electrode active material layer 18 are covered by the negative electrode side second electrolyte layer 12b. By covering the end face of the negative electrode current collector foil 17 and the negative electrode active material layer 18 by coating the back surface of the other side edge 17b of the negative electrode current collector foil 17 with the negative electrode side third electrolyte layer 12c. Peeling can be suppressed. As a result, a decrease in the battery capacity can be prevented, and the drying of the negative electrode active material layer 18 can be suppressed, so that the cycle characteristics of the battery 10 can be improved. Further, the other side edge 18b of the negative electrode active material layer 18 also contributes to occlusion and release of lithium ions, so that the discharge capacity and output characteristics of the battery 10 can be improved.
[0030]
Further, by covering the other side edge 13b of the negative electrode sheet 13 with the polymer electrolyte layer 12, the other side edge 17b of the negative electrode current collector foil 17 and the other side edge 18b of the negative electrode active material layer 18 are not exposed. . As a result, when the stacked body 24 is folded and assembled, the positive electrode sheet 11 and the negative electrode sheet 13 do not come into contact with each other, so that a short circuit in the battery 10 can be prevented.
[0031]
9 to 13 show a second embodiment of the present invention. 9 to 13, the same reference numerals as those in FIGS. 1 to 8 indicate the same parts.
In this embodiment, the polymer electrolyte layer 42 is formed not from the negative electrode sheet 13 but from the surface of the positive electrode sheet 11 to the other side edge 11b (FIGS. 9, 12 and 13). The polymer electrolyte layer 42 is formed on the positive electrode side first electrolyte layer 42 a formed on the surface of the positive electrode sheet 11, and formed on the end face of the other side edge 11 b of the positive electrode sheet 11 connected to the positive electrode side first electrolyte layer 42 a. And a positive electrode-side third electrolyte layer 42c connected to the positive electrode-side second electrolyte layer 42b and having a predetermined width and thickness on the back surface of the positive electrode sheet 11. The positive electrode-side first electrolyte layer 42a has one side edge located on the positive electrode current collector foil 14 that is outside the one side edge 15a of the positive electrode active material layer 15 by a predetermined width in the width direction, and the other side edge. The edge is formed so as to coincide with the other side edge 15b of the positive electrode active material layer 15, that is, so as to cover the surface of the positive electrode active material layer 15 and the end face of one side edge 15a. The positive electrode side second electrolyte layer 42 b is formed so as to cover the end face of the other side edge 14 b of the positive electrode current collector foil 14 and the end face of the other side edge 15 b of the positive electrode active material layer 15.
[0032]
Further, the positive electrode side third electrolyte layer 42c has a width of 0.5 to 20 mm, preferably 3 to 12 mm, and a thickness of 2 to 100 μm, preferably, on the back surface of the other side edge 14 b of the positive electrode current collector foil 14. It is formed to have a thickness of 10 to 60 μm. The reason why the width of the positive-electrode-side third electrolyte layer 42c is limited to the range of 0.5 to 20 mm is that the width of the negative-electrode-side third electrolyte layer of the first embodiment is limited to the range of 0.5 to 20 mm. Is the same as Further, the reason why the thickness of the positive-electrode-side third electrolyte layer 42c is limited to the range of 2 to 100 mm is that the thickness of the negative-electrode-side third electrolyte layer of the first embodiment is limited to the range of 2 to 100 mm. The same is true. Except for the above, the configuration is the same as that of the first embodiment.
[0033]
A method for manufacturing the thus-configured lithium ion polymer secondary battery 40 will be described.
(1) Production of positive electrode sheet 11
The positive electrode sheet 11 is produced in the same manner as the positive electrode sheet of the first embodiment (FIG. 12B).
(2) Formation of polymer electrolyte layer 42 on positive electrode sheet 11
First, an electrolyte slurry having a viscosity of 0.5 to 45 P is prepared by mixing a polymer, an electrolytic solution and a lithium metal salt. Next, the slurry is continuously applied to the surfaces and side edges of the belt-shaped positive electrode current collector foil 14 and the positive electrode active material layer 15 by a doctor blade method. At this time, the electrolyte slurry is stored in a tank for an applicator having the same flat nozzle as that of the first embodiment, and one end of the flat nozzle is moved in a width direction from the one side edge 15a of the positive electrode active material layer 15 by a predetermined width. With the other end of the flat nozzle positioned on the outer roller in the width direction by a predetermined width from the other side edge 15 b of the positive electrode active material layer 15, the positive electrode is positioned on the outer positive electrode current collector foil 14. While moving the current collector foil 14 in the longitudinal direction, the electrolyte slurry is continuously discharged from the flat nozzle. As a result, the electrolyte slurry becomes part of the surface of the positive electrode current collector foil 14, the entire surface of the positive electrode active material layer 15, the end surface of the other side edge 14b of the positive electrode current collector foil 14, and the other of the positive electrode active material layer 15. It is continuously applied to the end surface of the side edge 15b and the back surface of the other side edge 14b of the positive electrode current collector foil 14. Here, the reason why the electrolyte slurry is also applied to the back surface of the other side edge 14b of the positive electrode current collector foil 14 is that the slurry has a relatively low viscosity of 0.5 to 45P, This is because it also goes around the back surface of the other side edge 14b of the foil 14.
[0034]
Next, by drying the continuously applied electrolyte slurry, a positive electrode-side first electrolyte layer 42a covering a part of the surface of the positive electrode current collector foil 14 and the entire surface of the positive electrode active material layer 15, A positive-electrode-side second electrolyte layer 42b covering the end surface of the other side edge 14b of the body foil 14 and the end surface of the other side edge 15b of the positive electrode active material layer 15; and the other side edge 14b of the positive electrode current collector foil 14 A polymer electrolyte layer 42 composed of the positive electrode side third electrolyte layer 42c covering the back surface is formed (FIG. 12C). Thereby, the positive electrode sheet 11 having the polymer electrolyte layer 42 is manufactured.
[0035]
(3) Preparation of negative electrode sheet 13
The band-shaped negative electrode sheet 13 is produced in the same manner as the band-shaped negative electrode sheet of the first embodiment (FIG. 11B), and the band-shaped negative electrode sheet 13 is cut into a predetermined length to obtain a final shape. Are produced (FIG. 11C).
(4) Thermocompression bonding of the positive electrode sheet 11 and the negative electrode sheet 13
First, on the positive electrode sheet 11 with the polymer electrolyte layer 42 facing upward, a plurality of negative electrode sheets 13 with the negative electrode active material layer 18 facing downward are arranged at predetermined intervals to produce a laminate 44 (FIG. 13). Next, the laminated body 44 is inserted between the pair of rollers 25, 25 heated to a predetermined temperature and rotating in the direction of the solid arrow, from the direction shown by the broken arrow. Thus, the positive electrode sheet 11 and the negative electrode sheet 13 are thermocompression-bonded with the polymer electrolyte layer 42 interposed therebetween. Note that one side edge 14a of the band-shaped positive electrode current collector foil 14 protrudes from the other side edge 13b of the plurality of negative electrode sheets 13, and one side edge 17a of the plurality of negative electrode current collector foils 17 has a band shape. The negative electrode sheet 13 is arranged on the positive electrode sheet 11 so as to protrude from the other side edge 11b of the positive electrode sheet 11.
(5) Folding of the laminated body 44 and sealing of the folded laminated body 44
The operation of folding the laminate 44 and the operation of sealing the folded laminate 44 are performed in the same manner as in the first embodiment.
[0036]
In the lithium ion polymer secondary battery 40 manufactured as described above, the other side edge 11b of the positive electrode sheet 11 is covered with the polymer electrolyte layer 42, that is, the other side edge of the first positive electrode side electrolyte layer 42a has a positive electrode. The upper surface of the other side edge 15b of the active material layer 15 is covered, and the end surface of the other side edge 14b of the positive electrode current collector foil 14 and the other side edge of the positive electrode active material layer 15 are covered with the positive electrode side second electrolyte layer 42b. By covering the end face of the positive electrode current collector foil 14 and the positive electrode active material layer 15 by coating the back surface of the other side edge 14b of the positive electrode current collector foil 14 with the positive electrode side third electrolyte layer 42c. Peeling can be suppressed. As a result, a decrease in battery capacity can be prevented, and drying of the positive electrode active material layer 15 can be suppressed, so that the cycle characteristics of the battery 40 can be improved. Further, the other side edge 15b of the positive electrode active material layer 15 also contributes to occlusion and release of lithium ions, so that the discharge capacity and output characteristics of the battery 40 can be improved.
[0037]
Further, by covering the other side edge 11b of the positive electrode sheet 11 with the polymer electrolyte layer 42, the other side edge 11b of the positive electrode sheet 11 is not exposed. As a result, when the stacked body 44 is folded and assembled, the positive electrode sheet 11 and the negative electrode sheet 13 do not come into contact with each other, so that a short circuit in the battery 40 can be prevented.
[0038]
14 to 18 show a third embodiment of the present invention. 14 to 18, the same reference numerals as those in FIGS. 1 to 13 indicate the same parts.
In this embodiment, the polymer electrolyte layer 52 is formed from the surface of the negative electrode sheet 13 to the other side edge 13b, and is formed from the surface of the positive electrode sheet 11 to the other side edge 11b. The polymer electrolyte layer 52 includes the same negative electrode-side first electrolyte layer 12a, negative electrode-side second electrolyte layer 12b, and negative electrode-side third electrolyte layer 12c as in the first embodiment, and the same positive electrode as in the second embodiment. It has a first electrolyte layer 42a, a second electrolyte layer 42b on the positive electrode side, and a third electrolyte layer 42c on the positive electrode side. Except for the above, the configuration is the same as that of the first embodiment.
[0039]
A method for manufacturing the lithium ion polymer secondary battery 50 thus configured will be described.
(1) Preparation of the positive electrode sheet 11 and formation of the polymer electrolyte layer 52 on the positive electrode sheet 11
The positive electrode sheet 11 is produced in the same manner as in the second embodiment. The positive electrode sheet 11 has a positive electrode-side first electrolyte layer 42a, a positive electrode-side second electrolyte layer 42b, and a positive electrode sheet in the same manner as in the second embodiment. The side third electrolyte layers 42c are respectively formed.
(2) Preparation of negative electrode sheet 13 and formation of polymer electrolyte layer 52 on negative electrode sheet 13
The negative electrode sheet 13 is produced in the same manner as in the first embodiment. The negative electrode sheet 13 has a negative electrode-side first electrolyte layer 12a, a negative electrode-side second electrolyte layer 12b, and a negative electrode similar to the first embodiment. The side third electrolyte layers 12c are respectively formed.
[0040]
(3) Thermocompression bonding of the positive electrode sheet 11 and the negative electrode sheet 13
On the positive electrode sheet 11 with the positive electrode side first electrolyte layer 42a facing upward, a plurality of negative electrode sheets 13 with the negative electrode side first electrolyte layer 12a facing downward are arranged at predetermined intervals, and the laminate 54 is formed. After fabrication (FIG. 18), the positive electrode sheet 11 and the negative electrode sheet 13 are thermocompression-bonded via the polymer electrolyte layer 52 in the same manner as in the first embodiment.
(4) Folding of the laminated body 54 and sealing of the folded laminated body 54
The operation of folding the laminate 54 and the operation of sealing the folded laminate 54 are performed in the same manner as in the first embodiment.
[0041]
In the lithium ion polymer secondary battery 50 manufactured as described above, the other side edge 13b of the negative electrode sheet 13 and the other side edge 11b of the positive electrode sheet 11 are covered with the polymer electrolyte layer 52, that is, the negative electrode side first electrolyte The other side edge of the layer 12a covers the upper surface of the other side edge 18b of the negative electrode active material layer 18, and the end surface of the other side edge 17b of the negative electrode current collector foil 17 at the negative side second electrolyte layer 12b and The end face of the other side edge 18b of the anode active material layer 18 is covered, the back surface of the other side edge 17b of the anode current collector foil 17 is covered with the anode side third electrolyte layer 12c, and the cathode side first electrolyte layer is covered. The upper surface of the other side edge 15b of the positive electrode active material layer 15 is covered by the other side edge of the positive electrode active material layer 42, and the end surface of the other side edge 14b of the positive electrode current collector foil 14 and the positive electrode by the positive electrode side second electrolyte layer 42b. Covers the end surface of the other side edge 15b of the active material layer 15 Further, by covering the back surface of the other side edge 14b of the positive electrode current collector foil 14 with the positive electrode side third electrolyte layer 42c, the negative electrode current collector foil 17 and the negative electrode active material layer 18 are separated, and the positive electrode current collector Peeling of the body foil 14 and the positive electrode active material layer 15 can be suppressed. As a result, a decrease in the battery capacity can be prevented, and the drying of the negative electrode active material layer 18 and the positive electrode active material 15 layer can be suppressed, so that the cycle characteristics of the battery 50 can be improved as compared with the batteries of the first or second embodiment. Further, the other side edge 18b of the negative electrode active material layer 18 and the other side edge 15b of the positive electrode active material layer 15 also contribute to the occlusion and release of lithium ions. It can be improved over the battery of the embodiment.
[0042]
Further, the other side edge 13b of the negative electrode sheet 13 and the other side edge 11b of the positive electrode sheet 11 are covered with a polymer electrolyte layer 52, so that the other side edge 13b of the negative electrode sheet 13 and the other side edge of the positive electrode sheet 11 are covered. 11b is no longer exposed. As a result, when the laminate 54 is folded and assembled, the positive electrode sheet 11 and the negative electrode sheet 13 do not come into contact with each other, so that a short circuit in the battery 50 can be reliably prevented.
[0043]
FIG. 19 shows a fourth embodiment of the present invention. 19, the same reference numerals as those in FIG. 1 indicate the same parts.
In this embodiment, the polymer electrolyte layer 62 is formed from the surface of the negative electrode sheet 13 to the other side edge 13b, and the first negative electrode side electrolyte layer 12a formed on the surface of the negative electrode sheet 13 and the first negative electrode side electrolyte layer And a negative electrode side second electrolyte layer 12b formed on the end face of the other side edge 13b of the negative electrode sheet 13 so as to be connected to the negative electrode sheet 12a. In this embodiment, the negative electrode-side third electrolyte layer formed on the back surface of the negative electrode sheet in the first embodiment is not formed. Except for the above, the configuration is the same as that of the first embodiment.
[0044]
A method for manufacturing the lithium ion polymer secondary battery 60 thus configured will be described.
(1) Production of positive electrode sheet 11
The positive electrode sheet 11 is manufactured in the same manner as in the first embodiment.
{Circle around (2)} Preparation of strip-shaped negative electrode sheet 13
The strip-shaped negative electrode sheet 13 is produced in the same manner as in the first embodiment.
[0045]
(3) Formation of polymer electrolyte layer 62 on negative electrode sheet 13
First, an electrolyte slurry having a viscosity of 45 to 80 P is prepared by mixing a polymer, an electrolytic solution and a lithium metal salt. Next, the slurry is continuously applied to the surfaces and side edges of the strip-shaped negative electrode current collector foil 17 and the negative electrode active material layer 18 by the doctor blade method in the same manner as in the first embodiment. As a result, the electrolyte slurry becomes part of the surface of the negative electrode current collector foil 17, the entire surface of the negative electrode active material layer 18, the end surface of the other side edge 17 b of the negative electrode current collector foil 17 and the other of the negative electrode active material layer 18. It is continuously applied to the end face of the side edge 18b. Here, the reason that the electrolyte slurry does not wrap around the back surface of the other side edge 17b of the negative electrode current collector foil 17 is because the viscosity of the slurry is relatively high at 45 to 80P.
[0046]
Next, by drying the continuously applied electrolyte slurry, the negative electrode-side first electrolyte layer 12a covering a part of the surface of the negative electrode current collector foil 17 and the entire surface of the negative electrode active material layer 18; A polymer electrolyte layer 62 composed of an end face of the other side edge 17b of the body foil 17 and a negative electrode side second electrolyte layer 12b covering the end face of the other side edge 18b of the negative electrode active material layer 18 is formed. Further, by cutting the strip-shaped negative electrode sheet 13 into a predetermined length together with the strip-shaped polymer electrolyte layer 62, the final shape negative electrode sheet 13 having the polymer electrolyte layer 62 is produced.
[0047]
(4) Thermocompression bonding of the positive electrode sheet 11 and the negative electrode sheet 13
On the positive electrode sheet 11 with the positive electrode active material layer 15 facing upward, a plurality of negative electrode sheets 13 with the negative electrode side first electrolyte layer 12a facing downward are arranged at predetermined intervals, and after forming a laminate The positive electrode sheet 11 and the negative electrode sheet 13 are thermocompression-bonded via the polymer electrolyte layer 62 in the same manner as in the first embodiment.
5) Folding of the laminate and sealing of the folded laminate
The operation of folding the laminate and the operation of sealing the folded laminate are performed in the same manner as in the first embodiment.
[0048]
In the lithium ion polymer secondary battery 60 manufactured as described above, the other side edge 13b of the negative electrode sheet 13 is covered with the polymer electrolyte layer 62, that is, the negative electrode is formed on the other side edge of the negative electrode side first electrolyte layer 12a. The upper surface of the other side edge 18b of the active material layer 18 is covered, and the end surface of the other side edge 17b of the negative electrode current collector foil 17 and the other side edge of the negative electrode active material layer 18 are covered by the negative electrode side second electrolyte layer 12b. By covering the end face of 18b, peeling of the negative electrode current collector foil 17 and the negative electrode active material layer 18 can be suppressed. As a result, a decrease in battery capacity can be prevented, and drying of the negative electrode active material layer 18 can be suppressed, so that the cycle characteristics of the battery 60 can be improved. Further, the other side edge 18b of the negative electrode active material layer 18 also contributes to occlusion and release of lithium ions, so that the discharge capacity and output characteristics of the battery 60 can be improved.
[0049]
Further, by covering the other side edge 13b of the negative electrode sheet 13 with the polymer electrolyte layer 62, the end face of the other side edge 13b of the negative electrode sheet 13 is not exposed. As a result, when the stacked body is folded and assembled, the positive electrode sheet 11 and the negative electrode sheet 13 do not come into contact with each other, so that a short circuit in the battery 60 can be prevented.
[0050]
FIG. 20 shows a fifth embodiment of the present invention. 20, the same reference numerals as those in FIG. 9 indicate the same parts.
In this embodiment, a polymer electrolyte layer 72 is formed from the surface of the positive electrode sheet 11 to the other side edge, and the first positive electrode layer 42a formed on the surface of the positive electrode sheet 11 and the first positive electrolyte layer 42a And a positive electrode side second electrolyte layer 42b formed on the end surface of the other side edge 11b of the positive electrode sheet 11. Note that, in this embodiment, the positive electrode side third electrolyte layer formed on the back surface of the positive electrode sheet in the second embodiment is not formed. Except for the above, the configuration is the same as that of the second embodiment.
[0051]
A method for manufacturing the thus-configured lithium ion polymer secondary battery 70 will be described.
(1) Production of positive electrode sheet 11
The positive electrode sheet 11 is manufactured in the same manner as in the first embodiment.
(2) Formation of polymer electrolyte layer 72 on positive electrode sheet 11
First, an electrolyte slurry having a viscosity of 45 to 80 P is prepared by mixing a polymer, an electrolytic solution and a lithium metal salt. Next, the slurry is continuously applied to the surfaces and side edges of the belt-shaped positive electrode current collector foil 14 and the positive electrode active material layer 15 by the doctor blade method in the same manner as in the second embodiment. As a result, the electrolyte slurry becomes part of the surface of the positive electrode current collector foil 14, the entire surface of the positive electrode active material layer 15, the end face of the other side edge 14b of the positive electrode current collector foil 14, and the other of the positive electrode active material layer 15. It is continuously applied to the end face of the side edge 15b. Here, the reason that the electrolyte slurry does not wrap around to the back surface of the other side edge 14b of the positive electrode current collector foil 14 is because the viscosity of the slurry is relatively high at 45 to 80P. Next, by drying the continuously applied electrolyte slurry, a positive electrode-side first electrolyte layer 42a covering a part of the surface of the positive electrode current collector foil 14 and the entire surface of the positive electrode active material layer 15, A polymer electrolyte layer 72 composed of an end face of the other side edge 14b of the body foil 14 and a positive electrode side second electrolyte layer 42b covering the end face of the other side edge 15a of the positive electrode active material layer 15 is formed. Thus, the belt-shaped positive electrode sheet 11 having the polymer electrolyte layer 72 is manufactured.
[0052]
(3) Preparation of negative electrode sheet 13
The negative electrode sheet 13 is manufactured in the same manner as in the second embodiment.
(4) Thermocompression bonding of the positive electrode sheet 11 and the negative electrode sheet 13
On the positive electrode sheet 11 with the positive electrode side first electrolyte layer 42a facing up, a plurality of negative electrode sheets 13 with the negative electrode active material layer 18 facing down are arranged at predetermined intervals, to form a laminate. The positive electrode sheet 11 and the negative electrode sheet 13 are thermocompression-bonded via the polymer electrolyte layer 72 in the same manner as in the first embodiment.
5) Folding of the laminate and sealing of the folded laminate
The operation of folding the laminate and the operation of sealing the folded laminate are performed in the same manner as in the first embodiment.
[0053]
In the lithium ion polymer secondary battery 70 manufactured in this manner, the other side edge 11b of the positive electrode sheet 11 is covered with the polymer electrolyte layer 72, that is, the positive electrode is formed on the other side edge of the positive electrode side first electrolyte layer 42a. The upper surface of the other side edge 15b of the active material layer 15 is covered, and the end surface of the other side edge 14b of the positive electrode current collector foil 14 and the other side edge of the positive electrode active material layer 15 are covered with the positive electrode side second electrolyte layer 42b. By covering the end face of 15b, peeling of the positive electrode current collector foil 14 and the positive electrode active material layer 15 can be suppressed. As a result, a decrease in battery capacity can be prevented, and drying of the positive electrode active material layer 15 can be suppressed, so that the cycle characteristics of the battery 70 can be improved. Further, the other side edge 15b of the positive electrode active material layer 15 also contributes to occlusion and release of lithium ions, so that the discharge capacity and output characteristics of the battery 70 can be improved.
[0054]
Further, by covering the other side edge 11b of the positive electrode sheet 11 with the polymer electrolyte layer 72, the end surface of the other side edge 11b of the positive electrode sheet 11 is not exposed. As a result, when the stack is folded and assembled, the positive electrode sheet 11 and the negative electrode sheet 13 do not come into contact with each other, so that a short circuit in the battery 70 can be prevented.
[0055]
FIG. 21 shows a sixth embodiment of the present invention. 21, the same reference numerals as those in FIG. 14 indicate the same parts.
In this embodiment, the polymer electrolyte layer 82 is formed from the surface of the negative electrode sheet 13 to the other side edge 13b, and is formed from the surface of the positive electrode sheet 11 to the other side edge 11b. The polymer electrolyte layer 82 has the same negative electrode side first electrolyte layer 12a and the same negative electrode side second electrolyte layer 12b as the polymer electrolyte layer of the fourth embodiment, and the same positive electrode as the polymer electrolyte layer of the fifth embodiment. It has a first side electrolyte layer 42a and a positive side second electrolyte layer 42b. In this embodiment, the negative electrode side third electrolyte layer formed on the back surface of the negative electrode sheet and the positive electrode side third electrolyte layer formed on the back surface of the positive electrode sheet in the third embodiment are not formed. Except for the above, the configuration is the same as that of the third embodiment.
[0056]
A method for manufacturing the lithium ion polymer secondary battery 80 thus configured will be described.
(1) Preparation of the positive electrode sheet 11 and formation of the polymer electrolyte layer 82 on the positive electrode sheet 11
The positive electrode sheet 11 is manufactured in the same manner as in the fifth embodiment. The positive electrode side first electrolyte layer 42a and the positive electrode side second electrolyte layer 42b are formed on the positive electrode sheet 11 in the same manner as in the fifth embodiment. It is formed.
(2) Preparation of negative electrode sheet 13 and formation of polymer electrolyte layer 82 on negative electrode sheet 13
The negative electrode sheet 13 is produced in the same manner as in the fourth embodiment. The negative electrode sheet 13 has a negative electrode-side first electrolyte layer 12a and a negative electrode-side second electrolyte layer 12b in the same manner as in the fourth embodiment. It is formed.
[0057]
(3) Thermocompression bonding of the positive electrode sheet 11 and the negative electrode sheet 13
On the positive electrode sheet 11 with the positive electrode side first electrolyte layer 42a facing upward, a plurality of negative electrode sheets 13 with the negative electrode side first electrolyte layer 12a facing downward are arranged at predetermined intervals to produce a laminate. After that, the positive electrode sheet 11 and the negative electrode sheet 13 are thermocompression-bonded via the polymer electrolyte layer 82 in the same manner as in the first embodiment.
(4) Folding of the laminate and sealing of the folded laminate
The operation of folding the laminate and the operation of sealing the folded laminate are performed in the same manner as in the first embodiment.
[0058]
In the lithium ion polymer secondary battery 80 manufactured in this manner, the other side edge 13b of the negative electrode sheet 13 and the other side edge 11b of the positive electrode sheet 11 are covered with the polymer electrolyte layer 82, that is, the negative electrode side first electrolyte The other side edge of the layer 12a covers the upper surface of the other side edge 15b of the negative electrode active material layer 15, and the negative electrode side second electrolyte layer 12b has an end surface of the other side edge 17b of the negative electrode current collector foil 17 and The end face of the other side edge 18b of the negative electrode active material layer 18 is covered, and the other side edge of the positive electrode side first electrolyte layer 42a covers the upper surface of the other side edge 15b of the positive electrode active material layer 15; By covering the end face of the other side edge 14b of the positive electrode current collector foil 14 and the end face of the other side edge 15b of the positive electrode active material layer 15 with the second side electrolyte layer 42b, the negative electrode current collector foil 17 and the negative electrode Peeling of active material layer 18 and positive electrode current collector foil 4 and can be suppressed and peeling of the positive electrode active material layer 15. As a result, a decrease in battery capacity can be prevented, and drying of the negative electrode active material layer 18 and the positive electrode active material layer 15 can be suppressed, so that the cycle characteristics of the battery 80 can be improved as compared with the batteries of the fourth or fifth embodiment. Further, the other side edge 18b of the negative electrode active material layer 18 and the other side edge 15b of the positive electrode active material layer 15 also contribute to the occlusion and release of lithium ions. It can be improved over the battery of the embodiment.
[0059]
Further, by covering the other side edge 13b of the negative electrode sheet 13 and the other side edge 11b of the positive electrode sheet 11 with the polymer electrolyte layer 82, the end face of the other side edge 13b of the negative electrode sheet 13 and the other side of the positive electrode sheet 11 And the end surface of the side edge 11b is not exposed. As a result, when the stacked body is folded and assembled, the positive electrode sheet 11 and the negative electrode sheet 13 do not come into contact with each other, so that a short circuit in the battery 80 can be reliably prevented.
[0060]
【Example】
Next, examples of the present invention will be described in detail together with comparative examples.
<Example 1>
First, a belt-shaped positive electrode sheet 11 was produced (FIG. 7). That is, LiCoO Two 194 g of powder and 6 g of graphite powder (trade name: Ketjen Black) were dispersed and mixed in an N-methylpyrrolidone solution of polyvinylidene fluoride to prepare a positive electrode active material slurry. Is continuously applied to the upper surface of the Al-made positive electrode current collector foil 14 having a length of 30 m by a doctor blade method and dried, and the band-shaped positive electrode active material layer 15 is formed on the upper surface of the band-shaped positive electrode current collector foil 14. Formed.
[0061]
On the other hand, a plurality of negative electrode sheets 13 were produced (FIG. 6). That is, a negative electrode active material slurry obtained by dispersing and mixing 500 g of flaky natural graphite powder in an N-methylpyrrolidone solution of polyvinylidene fluoride on the upper surface of a negative electrode current collector foil 17 made of Cu having a width of 20 cm and a length of 30 m. Was intermittently applied by a doctor blade method and dried to form a strip-shaped negative electrode active material layer 18 on the upper face of the strip-shaped negative electrode current collector foil 17. Next, 180 g of vinylidene fluoride-hexafluoropropylene copolymer (manufactured by Elphatochem, Inc., Kynar 2810; a product containing 12 wt% of hexafluoropropylene) was dissolved in 1000 g of dimethyl carbonate at 50 ° C., and further a concentration of 1 mol / liter as an electrolytic solution. Lithium phosphorus hexafluoride (LiPF 6 ) Was dissolved in a mixed solution of ethylene carbonate and propylene carbonate (2: 1 by weight) with stirring to prepare an electrolyte slurry having a viscosity of 22P. This electrolyte slurry was continuously applied to the upper surface and the other side edge of the negative electrode current collector foil 17 and the negative electrode active material layer 18 by a doctor blade method (FIGS. 4 and 5).
[0062]
At this time, the electrolyte slurry 21 is stored in a coating machine tank 22 having a flat nozzle 22a, and one end of the flat nozzle 22a is separated from the one side edge 18b of the negative electrode active material layer 18 by a predetermined width in the width direction outside of the negative electrode current collector. With the other end of the flat nozzle 22a positioned on the roller 23 on the outer side in the width direction by a predetermined width from the other side edge 18b of the negative electrode active material layer 18, the negative electrode current collector foil The electrolyte slurry 21 was continuously discharged from the flat nozzle 22a while moving 17 in the longitudinal direction. As a result, the electrolyte slurry 21 forms part of the surface of the negative electrode current collector foil 17, the entire surface of the negative electrode active material layer 18, the end surface of the other side edge 17b of the negative electrode current collector foil 17, and the other of the negative electrode active material layer 18. And the back surface of the other side edge 17b of the negative electrode current collector foil 17 was continuously applied. Here, since the viscosity of the electrolyte slurry 21 was as low as 22P, the slurry 21 also spread to the back surface of the other side edge 17b of the negative electrode current collector foil 17.
[0063]
By drying the continuously applied electrolyte slurry 21, a negative electrode-side first electrolyte layer 12 a covering a part of the surface of the negative electrode current collector foil 17 and the entire surface of the negative electrode active material layer 18, and a negative electrode current collector A negative electrode-side second electrolyte layer 12b covering the end face of the other side edge 17b of the foil 17 and the end face of the other side edge 18b of the negative electrode active material layer 18, and the back surface of the other side edge 17b of the negative electrode current collector foil 17 The polymer electrolyte layer 12 composed of the negative electrode-side third electrolyte layer 12c covering the polymer electrolyte layer was formed (FIG. 6C). Here, the width of the negative electrode-side third electrolyte layer 12c was 5 mm, and the thickness was 35 μm. Further, the strip-shaped negative electrode sheet 13 on which the polymer electrolyte layer 12 is formed is cut together with the polymer electrolyte layer 12 to obtain ten negative electrode sheets 13 having the polymer electrolyte layer 12 and having a width and a length of 10 cm and 12 cm, respectively. (FIG. 6D).
[0064]
On the positive electrode sheet 11 with the positive electrode active material layer 15 facing upward, a plurality of negative electrode sheets 13 with the polymer electrolyte layer 12 facing downward are arranged at predetermined intervals and thermocompression bonded to form a laminate. 24 were produced (FIG. 8). As shown in FIG. 3, the laminated body 24 was formed by alternately zigzagging portions of the strip-shaped positive electrode sheet 11 where the negative electrode sheet 13 was not disposed, in a zigzag manner. Thereby, the positive electrode sheet 11 is folded so as to have a folding area having a width and a length of 11 cm and 12 cm, respectively. Between the positive electrode sheet 11, ten negative electrodes having a width and a length of 10 cm and 12 cm are respectively provided. The sheet 13 was sandwiched via the polymer electrolyte layer 12. Further, after the positive terminal 16 is connected to one side edge 14a of the positive electrode current collector foil 14 and the negative terminal 19 is connected to one side edge 17a of the negative electrode current collector foil 17, these terminals 16 and 19 project. The laminate 24 was sealed with a pair of package sheets 28, 28 so as to perform the above. This lithium ion polymer secondary battery 10 was used as Example 1.
[0065]
<Comparative Example 1>
Same as Example 1 except that the polymer electrolyte layer is composed of only the negative electrode-side first electrolyte layer that covers a part of the surface of the negative electrode current collector foil and the entire surface of the negative electrode active material layer. Thus, a lithium ion polymer secondary battery was produced. This battery was designated as Comparative Example 1.
[0066]
<Comparative test 1 and evaluation>
The cycle characteristics of the capacity retention of the lithium ion polymer secondary batteries of Example 1 and Comparative Example 1 were measured by a charge / discharge tester. The result is shown in FIG.
As is clear from FIG. 22, the slope in the cycle characteristics of the lithium ion polymer secondary battery in Example 1 is gentler than the slope in Comparative Example 1, and the cycle characteristics of the capacity retention rate in Example 1 are comparative. It was found that the capacity retention was improved from the cycle characteristics of Example 1. This is considered to be because in Example 1, no separation occurred between the other side edge of the negative electrode current collector foil and the other side edge of the negative electrode current collector.
[0067]
【The invention's effect】
As described above, according to the present invention, the polymer electrolyte layer is constituted by the negative electrode side first electrolyte layer and the negative electrode side second electrolyte layer, and the negative electrode side first electrolyte layer is formed on the surface of the negative electrode sheet. Since the negative electrode side second electrolyte layer was connected to the negative electrode side first electrolyte layer and formed on the end face of the other side edge of the negative electrode sheet, the other side edge of the negative electrode sheet was covered with the polymer electrolyte layer, The peeling of the electric foil and the negative electrode active material layer can be suppressed. As a result, since a decrease in battery capacity can be prevented, the cycle characteristics of the battery can be improved, and the discharge capacity and output characteristics of the battery can be improved. Further, the other side edge of the negative electrode active material layer also contributes to occlusion and release of lithium ions, so that the discharge capacity and output characteristics of the battery can be improved, and the other side edge of the negative electrode sheet is not exposed. Contact between the positive electrode sheet and the negative electrode sheet due to folding can be prevented, and a short circuit in the battery can be prevented.
[0068]
Further, the polymer electrolyte layer is composed of a positive electrode side first electrolyte layer and a positive electrode side second electrolyte layer, the positive electrode side first electrolyte layer is formed on the surface of the positive electrode sheet, and the positive electrode side second electrolyte layer is further formed of the positive electrode side first electrolyte layer. If connected to the electrolyte layer and formed on the end face of the other side edge of the positive electrode sheet, the other side edge of the positive electrode sheet is covered with the polymer electrolyte layer, and peeling of the positive electrode current collector foil and the positive electrode active material layer is performed. Since it can be suppressed, the same effects as above can be obtained. In addition, the other side edge of the positive electrode active material layer also contributes to occlusion and release of lithium ions, so that the discharge capacity and output characteristics of the battery can be improved, and the other side edge of the positive electrode sheet is not exposed. Contact between the positive electrode sheet and the negative electrode sheet due to folding can be prevented, and a short circuit in the battery can be prevented.
[0069]
Further, if the polymer electrolyte layer is composed of the negative electrode side first electrolyte layer, the negative electrode side second electrolyte layer, the positive electrode side first electrolyte layer and the positive electrode side second electrolyte layer, the other side edge of the negative electrode sheet and the positive electrode sheet The other side edge is covered with a polymer electrolyte layer, and the peeling of the negative electrode current collector foil and the negative electrode active material layer and the peeling of the positive electrode current collector foil and the positive electrode active material layer can be suppressed. Can be prevented, the cycle characteristics of the battery can be improved, and the discharge capacity and output characteristics of the battery can be improved from those in which one of the other side edge of the negative electrode sheet and the other side edge of the positive electrode sheet is coated with a polymer electrolyte layer. Can be improved. Also, the other side edge of the negative electrode active material layer also contributes to occlusion and release of lithium ions, so one of the other side edge of the negative electrode sheet or the other side edge of the positive electrode sheet is covered with a polymer electrolyte layer. Thus, the discharge capacity and output characteristics of the battery can be improved, and the other side edge of the negative electrode sheet and the other side edge of the positive electrode sheet are not exposed, so that the contact between the positive electrode sheet and the negative electrode sheet due to the folding of the laminate is ensured. The short circuit in the battery can be reliably prevented.
[0070]
In addition, if the negative electrode-side third electrolyte layer connected to the negative electrode-side second electrolyte layer is formed to have a predetermined width and thickness on the back surface of the negative electrode sheet, the upper surface of the other side edge of the negative electrode sheet will have a negative electrode-side first electrolyte. End surface of the other side edge is coated with the negative electrode side second electrolyte layer, and the back surface of the other side edge is coated with the negative electrode side third electrolyte layer. The side edges are not exposed at all, and the contact between the positive electrode sheet and the negative electrode sheet due to the folding of the positive electrode sheet can be reliably prevented.
[0071]
Further, if a positive electrode side third electrolyte layer connected to the positive electrode side second electrolyte layer is formed to have a predetermined width and thickness on the back surface of the positive electrode sheet, the upper surface of the other side edge of the positive electrode sheet becomes positive electrode side first electrolyte. The other side edge is covered with the positive electrode side second electrolyte layer, and the other side edge back surface is covered with the positive electrode side third electrolyte layer. The edge is not exposed at all, and the contact between the positive electrode sheet and the negative electrode sheet due to the folding of the positive electrode sheet can be reliably prevented.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of the lithium ion polymer secondary battery according to a first embodiment of the present invention, taken along line AA of FIG. 2;
FIG. 2 is a sectional view taken along line BB of FIG. 1;
FIG. 3 is an exploded perspective view showing a state immediately before sealing of the battery.
FIG. 4 is an essential part perspective view showing a state where an electrolyte slurry is applied to a negative electrode current collector foil by a doctor blade method.
FIG. 5 is a sectional view taken along line CC of FIG. 4;
FIG. 6 is a view showing a manufacturing process of a negative electrode sheet.
FIG. 7 is a diagram showing a manufacturing process of a positive electrode sheet.
FIG. 8 is a perspective view showing a state immediately before thermocompression bonding of a negative electrode sheet to a positive electrode sheet.
FIG. 9 is a sectional view taken along line DD of FIG. 10 showing a second embodiment of the present invention.
FIG. 10 is a sectional view taken along line EE of FIG. 9;
FIG. 11 is a view showing a manufacturing process of a negative electrode sheet.
FIG. 12 is a view showing a manufacturing process of a positive electrode sheet.
FIG. 13 is a perspective view showing a state immediately before thermocompression bonding of a negative electrode sheet to a positive electrode sheet.
FIG. 14 is a sectional view taken along line FF of FIG. 15 showing a third embodiment of the present invention.
FIG. 15 is a sectional view taken along line GG of FIG. 14;
FIG. 16 is a view showing a manufacturing process of a negative electrode sheet.
FIG. 17 is a view showing a manufacturing process of the positive electrode sheet.
FIG. 18 is a perspective view showing a state immediately before thermocompression bonding of a negative electrode sheet to a positive electrode sheet.
FIG. 19 is a sectional view illustrating a fourth embodiment of the present invention and corresponding to FIG. 1;
FIG. 20 is a sectional view showing a fifth embodiment of the present invention and corresponding to FIG. 9;
FIG. 21 is a sectional view showing a sixth embodiment of the present invention and corresponding to FIG. 14;
FIG. 22 is a diagram showing the cycle characteristics of the capacity retention of the lithium ion polymer secondary batteries of Example 1 and Comparative Example 1.
[Explanation of symbols]
10,40,50,60,70,80 Lithium ion polymer secondary battery
11 Positive electrode sheet
11a One side edge of positive electrode sheet
11b The other side edge of the positive electrode sheet
12,42,52,62,72,82 Polymer electrolyte layer
12a Negative electrode side first electrolyte layer
12b negative electrode side second electrolyte layer
12c negative electrode side third electrolyte layer
13 Negative electrode sheet
13a One side edge of the negative electrode sheet
13b The other side edge of the negative electrode sheet
14 Cathode current collector foil
14a One side edge of positive electrode current collector foil
14b The other side edge of the positive electrode current collector foil
15 Positive electrode active material layer
15a One side edge of positive electrode active material layer
15b The other side edge of the positive electrode active material layer
16 Positive terminal
17 Negative electrode current collector foil
17a One side edge of negative electrode current collector foil
17b The other side edge of the negative electrode current collector foil
18 Negative electrode active material layer
18a One side edge of negative electrode active material layer
18b The other side edge of the negative electrode active material layer
19 Negative electrode terminal
21 Electrolyte slurry
22 Tank for coating machine
22a flat nozzle
42a Positive electrode side first electrolyte layer
42b Positive electrode side second electrolyte layer
42c Positive electrode side third electrolyte layer

Claims (9)

帯状の正極集電体箔(14)の表面に正極活物質層(15)が形成され１回折り又は２回以上の葛折りにより折畳まれかつ一方の側縁(11a)に正極端子(16)が接続された正極シート(11)と、前記正極シート(11)の折畳み面積に相応した面積を有する負極集電体箔(17)の表面に負極活物質層(18)が形成され前記折畳まれる正極シート(11)の間にポリマー電解質層(12)を介して挟持されかつ一方の側縁(13a)に負極端子(19)が接続された負極シート(13)とを備えたリチウムイオンポリマー二次電池において、
前記ポリマー電解質層(12)が、
前記負極シート(13)の表面に形成された負極側第１電解質層(12a)と、
前記負極側第１電解質層(12a)に連設され前記負極シート(13)の他方の側縁(13b)の端面に形成された負極側第２電解質層(12b)と
を有することを特徴とすることを特徴とするリチウムイオンポリマー二次電池。A positive electrode active material layer (15) is formed on the surface of the belt-shaped positive electrode current collector foil (14), folded once or two or more times by folding, and has a positive electrode terminal (16) on one side edge (11a). ) Is connected to a positive electrode sheet (11), and a negative electrode active material layer (18) is formed on the surface of a negative electrode current collector foil (17) having an area corresponding to the folding area of the positive electrode sheet (11). A lithium sheet having a negative electrode sheet (13) sandwiched between a folded positive electrode sheet (11) via a polymer electrolyte layer (12) and having a negative electrode terminal (19) connected to one side edge (13a). In ionic polymer secondary batteries,
The polymer electrolyte layer (12),
A negative electrode-side first electrolyte layer (12a) formed on the surface of the negative electrode sheet (13);
And a negative electrode-side second electrolyte layer (12b) provided on the end surface of the other side edge (13b) of the negative electrode sheet (13) and connected to the negative electrode-side first electrolyte layer (12a). A lithium ion polymer secondary battery characterized in that: 帯状の正極集電体箔(14)の表面に正極活物質層(15)が形成され１回折り又は２回以上の葛折りにより折畳まれかつ一方の側縁(11a)に正極端子(16)が接続された正極シート(11)と、前記正極シート(11)の折畳み面積に相応した面積を有する負極集電体箔(17)の表面に負極活物質層(18)が形成され前記折畳まれる正極シート(11)の間にポリマー電解質層(42)を介して挟持されかつ一方の側縁(13a)に負極端子(19)が接続された負極シート(13)とを備えたリチウムイオンポリマー二次電池において、
前記ポリマー電解質層(42)が、
前記正極シート(11)の表面に形成された正極側第１電解質層(42a)と、
前記正極側第１電解質層(42a)に連設され前記正極シート(11)の他方の側縁(11b)の端面に形成された正極側第２電解質層(42b)と
を有することを特徴とすることを特徴とするリチウムイオンポリマー二次電池。A positive electrode active material layer (15) is formed on the surface of the belt-shaped positive electrode current collector foil (14), folded once or two or more times by folding, and has a positive electrode terminal (16) on one side edge (11a). ) Is connected to a positive electrode sheet (11), and a negative electrode active material layer (18) is formed on the surface of a negative electrode current collector foil (17) having an area corresponding to the folding area of the positive electrode sheet (11). A negative electrode sheet (13) sandwiched between a folded positive electrode sheet (11) via a polymer electrolyte layer (42) and a negative electrode terminal (19) connected to one side edge (13a). In ionic polymer secondary batteries,
The polymer electrolyte layer (42),
A positive electrode side first electrolyte layer (42a) formed on the surface of the positive electrode sheet (11);
A positive-electrode-side second electrolyte layer (42b) provided continuously with the positive-electrode-side first electrolyte layer (42a) and formed on the end face of the other side edge (11b) of the positive-electrode sheet (11). A lithium ion polymer secondary battery characterized in that: 帯状の正極集電体箔(14)の表面に正極活物質層(15)が形成され１回折り又は２回以上の葛折りにより折畳まれかつ一方の側縁(11a)に正極端子(16)が接続された正極シート(11)と、前記正極シート(11)の折畳み面積に相応した面積を有する負極集電体箔(17)の表面に負極活物質層(18)が形成され前記折畳まれる正極シート(11)の間にポリマー電解質層(52)を介して挟持されかつ一方の側縁(13a)に負極端子(19)が接続された負極シート(13)とを備えたリチウムイオンポリマー二次電池において、
前記ポリマー電解質層(52)が、
前記負極シート(13)の表面に形成された負極側第１電解質層(12a)と、
前記負極側第１電解質層(12a)に連設され前記負極シート(13)の他方の側縁(13b)の端面に形成された負極側第２電解質層(12b)と、
前記正極シート(11)の表面に形成された正極側第１電解質層(42a)と、
前記正極側第１電解質層(42a)に連設され前記正極シート(11)の他方の側縁(11b)の端面に形成された正極側第２電解質層(42b)と
を有することを特徴とすることを特徴とするリチウムイオンポリマー二次電池。A positive electrode active material layer (15) is formed on the surface of the belt-shaped positive electrode current collector foil (14), folded once or two or more times by folding, and has a positive electrode terminal (16) on one side edge (11a). ) Is connected to a positive electrode sheet (11), and a negative electrode active material layer (18) is formed on the surface of a negative electrode current collector foil (17) having an area corresponding to the folding area of the positive electrode sheet (11). A lithium sheet comprising a negative electrode sheet (13) sandwiched between a folded positive electrode sheet (11) via a polymer electrolyte layer (52) and having a negative electrode terminal (19) connected to one side edge (13a). In ionic polymer secondary batteries,
The polymer electrolyte layer (52),
A negative electrode-side first electrolyte layer (12a) formed on the surface of the negative electrode sheet (13);
A negative-electrode-side second electrolyte layer (12b) provided continuously to the negative-electrode-side first electrolyte layer (12a) and formed on an end surface of the other side edge (13b) of the negative-electrode sheet (13);
A positive electrode side first electrolyte layer (42a) formed on the surface of the positive electrode sheet (11);
A positive-electrode-side second electrolyte layer (42b) provided continuously with the positive-electrode-side first electrolyte layer (42a) and formed on the end face of the other side edge (11b) of the positive-electrode sheet (11). A lithium ion polymer secondary battery characterized in that: 負極側第２電解質層(12b)に連設され負極シート(13)の裏面に所定の幅及び厚さに形成された負極側第３電解質層(12c)を更に備えた請求項１又は３記載のリチウムイオンポリマー二次電池。The negative electrode-side third electrolyte layer (12c) formed to have a predetermined width and thickness on the back surface of the negative electrode sheet (13) and connected to the negative electrode-side second electrolyte layer (12b). Lithium ion polymer secondary battery. 正極側第２電解質層(42b)に連設され正極シート(11)の裏面に所定の幅及び厚さに形成された正極側第３電解質層(42c)を更に備えた請求項２又は３記載のリチウムイオンポリマー二次電池。The positive electrode-side third electrolyte layer (42c) formed to have a predetermined width and thickness on the back surface of the positive electrode sheet (11) and connected to the positive electrode-side second electrolyte layer (42b). Lithium ion polymer secondary battery. 帯状の負極集電体箔(17)の表面に、一方の側縁を前記負極集電体箔(17)の一方の側縁(17a)から所定の幅だけ内側に位置させかつ他方の側縁を前記負極集電体箔(17)の他方の側縁(17b)に一致させて帯状の負極活物質層(18)を形成する工程と、
扁平ノズル(22a)を有する塗布機用タンク(22)に粘度が０．５〜４５Ｐである前記電解質スラリー(21)を貯留する工程と、
前記扁平ノズル(22a)の一端を前記負極活物質層(18)の一方の側縁(18a)から所定の幅だけ幅方向外側の前記負極集電体箔(17)上に位置させかつ前記扁平ノズル(22a)の他端を前記負極活物質層(18)の他方の側縁(18b)から所定の幅だけ幅方向外側に位置させた状態で前記負極集電体箔(17)をその長手方向に移動させながら、前記扁平ノズル(22a)から前記電解質スラリー(21)を吐出することにより、前記電解質スラリー(21)を前記負極集電体箔(17)の表面の一部と前記負極活物質層(18)の全表面と前記負極集電体箔(17)の他方の側縁(17b)の端面と前記負極活物質層(18)の他方の側縁(18b)の端面と前記負極集電体箔(17)の他方の側縁(17b)の裏面に連続塗布する工程と、
前記連続塗布された電解質スラリー(21)を乾燥することにより、前記負極集電体箔(17)の表面の一部及び前記負極活物質層(18)の全表面を被覆する負極側第１電解質層(12a)と、前記負極集電体箔(17)の他方の側縁(17b)の端面及び前記負極活物質層(18)の他方の側縁(18b)の端面を被覆する負極側第２電解質層(12b)と、前記負極集電体箔(17)の他方の側縁(17b)の裏面を被覆する負極側第３電解質層(12c)とからなるポリマー電解質層(12)を形成する工程と、
前記帯状の負極集電体箔(17)を前記負極活物質層(18)及び前記ポリマー電解質層(12)とともに所定の長さに切断する工程と
を含むリチウムイオンポリマー二次電池の製造方法。On the surface of the strip-shaped negative electrode current collector foil (17), one side edge is located inside a predetermined width from one side edge (17a) of the negative electrode current collector foil (17) and the other side edge is positioned. Forming a strip-shaped negative electrode active material layer (18) in accordance with the other side edge (17b) of the negative electrode current collector foil (17),
A step of storing the electrolyte slurry (21) having a viscosity of 0.5 to 45 P in a coating machine tank (22) having a flat nozzle (22a),
One end of the flat nozzle (22a) is located on the negative electrode current collector foil (17) on the outside in the width direction by a predetermined width from one side edge (18a) of the negative electrode active material layer (18), and With the other end of the nozzle (22a) positioned outside the other side edge (18b) of the negative electrode active material layer (18) by a predetermined width in the width direction, the negative electrode current collector foil (17) is longitudinally extended. By discharging the electrolyte slurry (21) from the flat nozzle (22a) while moving the electrolyte slurry (21) in the direction, the electrolyte slurry (21) is partially discharged from the surface of the negative electrode current collector foil (17) and the negative electrode active material. The entire surface of the material layer (18), the end face of the other side edge (17b) of the negative electrode current collector foil (17), the end face of the other side edge (18b) of the negative electrode active material layer (18), and the negative electrode A step of continuously applying the back surface of the other side edge (17b) of the current collector foil (17),
By drying the continuously applied electrolyte slurry (21), a negative electrode side first electrolyte covering a part of the surface of the negative electrode current collector foil (17) and the entire surface of the negative electrode active material layer (18). A layer (12a), an end face of the other side edge (17b) of the anode current collector foil (17) and an end face of the other side edge (18b) of the anode active material layer (18). (2) forming a polymer electrolyte layer (12) comprising an electrolyte layer (12b) and a negative electrode-side third electrolyte layer (12c) covering the back surface of the other side edge (17b) of the negative electrode current collector foil (17); The process of
Cutting the strip-shaped negative electrode current collector foil (17) together with the negative electrode active material layer (18) and the polymer electrolyte layer (12) into a predetermined length. 帯状の正極集電体箔(14)の表面に、一方の側縁を前記正極集電体箔(14)の一方の側縁(14a)から所定の幅だけ内側に位置させかつ他方の側縁を前記正極集電体箔(14)の他方の側縁(14b)に一致させて帯状の正極活物質層(15)を形成する工程と、
扁平ノズルを有する塗布機用タンクに粘度が０．５〜４５Ｐである前記電解質スラリーを貯留する工程と、
前記扁平ノズルの一端を前記正極活物質層(15)の一方の側縁(15a)から所定の幅だけ幅方向外側の前記正極集電体箔(14)上に位置させかつ前記扁平ノズルの他端を前記正極活物質層(15)の他方の側縁(15b)から所定の幅だけ幅方向外側に位置させた状態で前記正極集電体箔(14)をその長手方向に移動させながら、前記扁平ノズルから前記電解質スラリーを吐出することにより、前記電解質スラリーを前記正極集電体箔(14)の表面の一部と前記正極活物質層(15)の全表面と前記正極集電体箔(14)の他方の側縁(14b)の端面と前記正極活物質層(15)の他方の側縁(15b)の端面と前記正極集電体箔(14)の他方の側縁(14b)の裏面に連続塗布する工程と、
前記連続塗布された電解質スラリーを乾燥することにより、前記正極集電体箔(14)の表面の一部及び前記正極活物質層(15)の全表面を被覆する正極側第１電解質層(42a)と、前記正極集電体箔(14)の他方の側縁(14b)の端面及び前記正極活物質層(15)の他方の側縁(15b)の端面を被覆する正極側第２電解質層(42b)と、前記正極集電体箔(14)の他方の側縁(14b)の裏面を被覆する正極側第３電解質層(42c)とからなるポリマー電解質層(42)を形成する工程と
を含むリチウムイオンポリマー二次電池の製造方法。On the surface of the belt-shaped positive electrode current collector foil (14), one side edge is located inside a predetermined width from one side edge (14a) of the positive electrode current collector foil (14) and the other side edge is positioned. Forming a strip-shaped positive electrode active material layer (15) in accordance with the other side edge (14b) of the positive electrode current collector foil (14),
Storing the electrolyte slurry having a viscosity of 0.5 to 45 P in a coating machine tank having a flat nozzle,
One end of the flat nozzle is positioned on the positive electrode current collector foil (14) in the width direction outside by a predetermined width from one side edge (15a) of the positive electrode active material layer (15). While moving the positive electrode current collector foil (14) in the longitudinal direction with its end positioned a predetermined width outward from the other side edge (15b) of the positive electrode active material layer (15), By discharging the electrolyte slurry from the flat nozzle, a part of the surface of the positive electrode current collector foil (14) and the entire surface of the positive electrode active material layer (15) and the positive electrode current collector foil The end face of the other side edge (14b) of (14), the end face of the other side edge (15b) of the positive electrode active material layer (15), and the other side edge (14b) of the positive electrode current collector foil (14) Continuous application on the back of the
By drying the continuously applied electrolyte slurry, a positive electrode-side first electrolyte layer (42a) covering a part of the surface of the positive electrode current collector foil (14) and the entire surface of the positive electrode active material layer (15) ) And a positive electrode side second electrolyte layer covering the end face of the other side edge (14b) of the positive electrode current collector foil (14) and the end face of the other side edge (15b) of the positive electrode active material layer (15). (42b) and a step of forming a polymer electrolyte layer (42) comprising a cathode-side third electrolyte layer (42c) covering the back surface of the other side edge (14b) of the cathode current collector foil (14). A method for producing a lithium ion polymer secondary battery comprising: 帯状の負極集電体箔(17)の表面に、一方の側縁を前記負極集電体箔(17)の一方の側縁(17a)から所定の幅だけ内側に位置させかつ他方の側縁を前記負極集電体箔(17)の他方の側縁(17b)に一致させて帯状の負極活物質層(18)を形成する工程と、
扁平ノズルを有する塗布機用タンクに粘度が４５〜８０Ｐである前記電解質スラリーを貯留する工程と、
前記扁平ノズルの一端を前記負極活物質層(18)の一方の側縁(18a)から所定の幅だけ幅方向外側の前記負極集電体箔(17)上に位置させかつ前記扁平ノズルの他端を前記負極活物質層(18)の他方の側縁(18b)から所定の幅だけ幅方向外側に位置させた状態で前記負極集電体箔(17)をその長手方向に移動させながら、前記扁平ノズルから前記電解質スラリーを吐出することにより、前記電解質スラリーを前記負極集電体箔(17)の表面の一部と前記負極活物質層(18)の全表面と前記負極集電体箔(17)の他方の側縁(17b)の端面と前記負極活物質層(18)の他方の側縁(18b)の端面に連続塗布する工程と、
前記連続塗布された電解質スラリーを乾燥することにより、前記負極集電体箔(17)の表面の一部及び前記負極活物質層(18)の全表面を被覆する負極側第１電解質層(12a)と、前記負極集電体箔(17)の他方の側縁(17b)の端面及び前記負極活物質層(18)の他方の側縁(18b)の端面を被覆する負極側第２電解質層(12b)とからなるポリマー電解質層(62)を形成する工程と、
前記帯状の負極集電体箔(17)を前記負極活物質層(18)及び前記ポリマー電解質層(62)とともに所定の長さに切断する工程と
を含むリチウムイオンポリマー二次電池の製造方法。On the surface of the strip-shaped negative electrode current collector foil (17), one side edge is located inside a predetermined width from one side edge (17a) of the negative electrode current collector foil (17) and the other side edge is positioned. Forming a strip-shaped negative electrode active material layer (18) in accordance with the other side edge (17b) of the negative electrode current collector foil (17),
Storing the electrolyte slurry having a viscosity of 45 to 80 P in a coating machine tank having a flat nozzle,
One end of the flat nozzle is positioned on the negative electrode current collector foil (17) on the outside in the width direction by a predetermined width from one side edge (18a) of the negative electrode active material layer (18). While moving the negative electrode current collector foil (17) in the longitudinal direction in a state where the end is located outside the width direction by a predetermined width from the other side edge (18b) of the negative electrode active material layer (18), By discharging the electrolyte slurry from the flat nozzle, a part of the surface of the negative electrode current collector foil (17), the entire surface of the negative electrode active material layer (18), and the negative electrode current collector foil (17) a step of continuously applying the end face of the other side edge (17b) and the end face of the other side edge (18b) of the negative electrode active material layer (18),
By drying the continuously applied electrolyte slurry, a negative electrode-side first electrolyte layer (12a) covering a part of the surface of the negative electrode current collector foil (17) and the entire surface of the negative electrode active material layer (18). ), And a negative-electrode-side second electrolyte layer covering the end face of the other side edge (17b) of the negative electrode current collector foil (17) and the end face of the other side edge (18b) of the negative electrode active material layer (18). Forming a polymer electrolyte layer (62) consisting of (12b) and
Cutting the strip-shaped negative electrode current collector foil (17) together with the negative electrode active material layer (18) and the polymer electrolyte layer (62) into a predetermined length. 帯状の正極集電体箔(14)の表面に、一方の側縁を前記正極集電体箔(14)の一方の側縁(14a)から所定の幅だけ内側に位置させかつ他方の側縁を前記正極集電体箔(14)の他方の側縁(14b)に一致させて帯状の正極活物質層(15)を形成する工程と、
扁平ノズルを有する塗布機用タンクに粘度が４５〜８０Ｐである前記電解質スラリーを貯留する工程と、
前記扁平ノズルの一端を前記正極活物質層(15)の一方の側縁(15a)から所定の幅だけ幅方向外側の前記正極集電体箔(14)上に位置させかつ前記扁平ノズルの他端を前記正極活物質層(15)の他方の側縁(15b)から所定の幅だけ幅方向外側に位置させた状態で前記正極集電体箔(14)をその長手方向に移動させながら、前記扁平ノズルから前記電解質スラリーを吐出することにより、前記電解質スラリーを前記正極集電体箔(14)の表面の一部と前記正極活物質層(15)の全表面と前記正極集電体箔(14)の他方の側縁(14b)の端面と前記正極活物質層(15)の他方の側縁(15b)の端面に連続塗布する工程と、
前記連続塗布された電解質スラリーを乾燥することにより、前記正極集電体箔(14)の表面の一部及び前記正極活物質層(15)の全表面を被覆する正極側第１電解質層(42a)と、前記正極集電体箔(14)の他方の側縁(14b)の端面及び前記正極活物質層(15)の他方の側縁(15b)の端面を被覆する正極側第２電解質層(42b)とからなるポリマー電解質層(72)を形成する工程と
を含むリチウムイオンポリマー二次電池の製造方法。On the surface of the belt-shaped positive electrode current collector foil (14), one side edge is located inside a predetermined width from one side edge (14a) of the positive electrode current collector foil (14) and the other side edge is positioned. Forming a strip-shaped positive electrode active material layer (15) in accordance with the other side edge (14b) of the positive electrode current collector foil (14),
Storing the electrolyte slurry having a viscosity of 45 to 80 P in a coating machine tank having a flat nozzle,
One end of the flat nozzle is positioned on the positive electrode current collector foil (14) in the width direction outside by a predetermined width from one side edge (15a) of the positive electrode active material layer (15). While moving the positive electrode current collector foil (14) in the longitudinal direction with its end positioned a predetermined width outward from the other side edge (15b) of the positive electrode active material layer (15), By discharging the electrolyte slurry from the flat nozzle, a part of the surface of the positive electrode current collector foil (14) and the entire surface of the positive electrode active material layer (15) and the positive electrode current collector foil A step of continuously applying the end face of the other side edge (14b) of the (14) and the end face of the other side edge (15b) of the positive electrode active material layer (15),
By drying the continuously applied electrolyte slurry, a positive electrode-side first electrolyte layer (42a) covering a part of the surface of the positive electrode current collector foil (14) and the entire surface of the positive electrode active material layer (15) ) And a positive electrode side second electrolyte layer covering the end face of the other side edge (14b) of the positive electrode current collector foil (14) and the end face of the other side edge (15b) of the positive electrode active material layer (15). Forming a polymer electrolyte layer (72) consisting of (42b).
JP2002376633A 2002-12-26 2002-12-26 Lithium ion polymer secondary battery Expired - Fee Related JP4232458B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2002376633A JP4232458B2 (en) 2002-12-26 2002-12-26 Lithium ion polymer secondary battery

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2002376633A JP4232458B2 (en) 2002-12-26 2002-12-26 Lithium ion polymer secondary battery

Publications (2)

Publication Number Publication Date
JP2004207118A true JP2004207118A (en) 2004-07-22
JP4232458B2 JP4232458B2 (en) 2009-03-04

Family

ID=32814046

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2002376633A Expired - Fee Related JP4232458B2 (en) 2002-12-26 2002-12-26 Lithium ion polymer secondary battery

Country Status (1)

Country Link
JP (1) JP4232458B2 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012043596A (en) * 2010-08-18 2012-03-01 Dainippon Screen Mfg Co Ltd Method of manufacturing battery, battery, vehicle, and electronic apparatus
JP2012119236A (en) * 2010-12-02 2012-06-21 Dainippon Screen Mfg Co Ltd Battery manufacturing method, battery, motor vehicle, rf-id tag, and electronic device
JP2018063752A (en) * 2016-10-11 2018-04-19 トヨタ自動車株式会社 Laminated battery manufacturing apparatus

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012043596A (en) * 2010-08-18 2012-03-01 Dainippon Screen Mfg Co Ltd Method of manufacturing battery, battery, vehicle, and electronic apparatus
JP2012119236A (en) * 2010-12-02 2012-06-21 Dainippon Screen Mfg Co Ltd Battery manufacturing method, battery, motor vehicle, rf-id tag, and electronic device
JP2018063752A (en) * 2016-10-11 2018-04-19 トヨタ自動車株式会社 Laminated battery manufacturing apparatus

Also Published As

Publication number Publication date
JP4232458B2 (en) 2009-03-04

Similar Documents

Publication Publication Date Title
JP4293501B2 (en) Electrochemical devices
WO2011001617A1 (en) Winding electrode group and battery
JP6032628B2 (en) Thin battery
JP5735096B2 (en) Non-aqueous secondary battery manufacturing method and non-aqueous secondary battery manufacturing method
JP2002298825A (en) Method of producing electrochemical device and the electrochemical device
JP7220617B2 (en) ALL-SOLID BATTERY AND METHOD FOR MANUFACTURING ALL-SOLID BATTERY
JP7351848B2 (en) Non-aqueous electrolyte secondary battery
JP2004071302A (en) Storage element module and its manufacturing method
JP4366775B2 (en) Solid electrolyte battery
CN109891640B (en) Electrode for nonaqueous electrolyte secondary battery and nonaqueous electrolyte secondary battery
CN109923700B (en) Electrode for nonaqueous electrolyte secondary battery and nonaqueous electrolyte secondary battery
JP2011187241A (en) Nonaqueous electrolyte secondary battery
JPH08273698A (en) Lithium secondary battery
JP3680809B2 (en) Lithium ion polymer secondary battery and manufacturing method thereof
JP7197536B2 (en) lithium ion secondary battery
JP4954468B2 (en) Winding electrode, manufacturing method thereof, and battery manufacturing method
JP3709495B2 (en) Lithium ion polymer secondary battery
JP3601283B2 (en) Non-aqueous electrolyte battery
JP2004319098A (en) Electrochemical cell and its manufacturing method
JP2004207118A (en) Lithium ion polymer secondary battery and its manufacturing method
JP2008251223A (en) Manufacturing method of lithium ion secondary battery, and lithium ion secondary battery
JPH11121043A (en) Manufacture of polymer secondary battery
JP2003092145A (en) Lithiumion polymer secondary battery
JP4811983B2 (en) Winding electrode, manufacturing method thereof, and battery using the same
JP2003142067A (en) Sheet-like battery

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20050318

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20080312

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20080624

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20080808

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20081118

A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20081201

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20111219

Year of fee payment: 3

R150 Certificate of patent or registration of utility model

Free format text: JAPANESE INTERMEDIATE CODE: R150

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20111219

Year of fee payment: 3

S531 Written request for registration of change of domicile

Free format text: JAPANESE INTERMEDIATE CODE: R313531

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20111219

Year of fee payment: 3

R350 Written notification of registration of transfer

Free format text: JAPANESE INTERMEDIATE CODE: R350

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20111219

Year of fee payment: 3

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20121219

Year of fee payment: 4

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20131219

Year of fee payment: 5

LAPS Cancellation because of no payment of annual fees