JP3709495B2

JP3709495B2 - Lithium ion polymer secondary battery

Info

Publication number: JP3709495B2
Application number: JP20106199A
Authority: JP
Inventors: 祐介渡會; 暁夫水口; さわ子竹内; 正小林; 晃裕樋上
Original assignee: Mitsubishi Materials Corp
Current assignee: Mitsubishi Materials Corp
Priority date: 1999-07-15
Filing date: 1999-07-15
Publication date: 2005-10-26
Anticipated expiration: 2019-07-15
Also published as: JP2001028273A

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の製造方法に関するものである。
【０００２】
【従来の技術】
近年のビデオカメラやノート型パソコン等のポータブル機器の普及により薄型の電池に対する需要が高まっている。この薄型の電池として、正極シートと負極シートを積層して形成されたリチウムイオンポリマー二次電池が知られている。この正極シートは、正極集電体箔の表面に活物質を形成することにより作られ、負極シートは負極集電体箔の表面に活物質を形成することにより作られる。正極シートの活物質と負極シートの活物質の間にはポリマー電解質層が介装される。この電池では、それぞれの活物質における電位差を電流として取出すための正極端子及び負極端子が正極集電体箔及び負極集電体箔に設けられ、このように積層されたものをパッケージで密閉することによりリチウムイオンポリマー二次電池が形成される。このリチウムイオンポリマー二次電池ではパッケージから引出された正極端子及び負極端子を電池の端子として使用することにより所望の電気が得られるようになっている。
【０００３】
【発明が解決しようとする課題】
しかし、このリチウムイオンポリマー二次電池の放電容量を増大させるには正極シート及び負極シートの面積を拡大させる必要がある。この正極シート及び負極シートの面積を単純に拡大するだけでは薄いけれども比較的広い面積を有する電池になり、その取扱いが困難になる不具合がある。この点を解消するために、拡大した正極シート及び負極シートを所望の大きさに折畳むことも考えられる。しかし、正極シート及び負極シートを積層した状態で折畳むと、折目部分における正極シート又は負極シートに撓みが生じ、その部分におけるシートが電解質層から剥離して電極と電解質界面の有効表面積が減少して放電容量が減少するとともに、電池内部に抵抗を生じさせて放電容量のサイクル特性を悪化させる不具合がある。また、撓みが比較的大きい場合にはその部分で正極シート及び負極シートが直接接触する、いわゆる内部ショートが生じる問題点もある。
本発明の目的は、内部ショートを確実に防止して放電容量を拡大するとともに、放電容量のサイクル特性を向上し得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。
【０００４】
【課題を解決するための手段】
請求項１に係る発明は、図１〜図６に示すように、帯状の正極集電体箔１８の一方の側部を除く表面に正極活物質１３と正極活物質１３を被覆するポリマー電解質層１７をこの順序で形成する工程と、帯状の負極集電体箔１５の他方の側部を除く表面に負極活物質１６と負極活物質１６を被覆するポリマー電解質層１７をこの順序で形成する工程と、帯状の正極集電体箔１８を正極活物質１３及びポリマー電解質層１７とともに所定の長さに切断して複数の短冊状正極集電体箔１２を得る工程と、正極活物質１６上のポリマー電解質層１７を負極活物質１３上のポリマー電解質層１７に密着させて正極活物質１３を負極活物質１６に対向させかつ短冊状正極集電体箔１２の一方の側縁１２ａが帯状の負極集電体箔１５の一方の側縁１５ａから突出し帯状の負極集電体箔１５の他方の側縁１５ｂが短冊状正極集電体箔１２の他方の側縁１２ｂから突出するように複数の短冊状正極集電体箔１２を所定のピッチで帯状の負極集電体箔１４上に配置する工程と、帯状の負極集電体箔１５を短冊状正極集電体箔１２が配置されていないところで交互に折曲げて帯状の負極集電体箔１４を折り畳む工程と、帯状の負極集電体箔１５の一方の側縁１５ａから突出して積層された複数の短冊状正極集電体箔１２の突出部１２ｃに正極端子２３の一端を設ける工程と、複数の短冊状正極集電体箔１２の他方の側縁１２ｂから突出して交互に折り畳まれた帯状の負極集電体箔１５の突出部１５ｃに負極端子２１の一端を設ける工程と、正極端子２３の他端及び負極端子２１の他端がそれぞれ外部に表出するように折畳まれた帯状の負極集電体箔１５を複数の短冊状正極集電体箔１２とともにパッケージシート２４で密封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。
【０００５】
請求項２に係る発明は、帯状の負極集電体箔の一方の側部を除く表面に負極活物質と負極活物質を被覆するポリマー電解質層をこの順序で形成する工程と、帯状の正極集電体箔の他方の側部を除く表面に正極活物質と正極活物質を被覆するポリマー電解質層をこの順序で形成する工程と、帯状の負極集電体箔を負極活物質及びポリマー電解質層とともに所定の長さに切断して複数の短冊状負極集電体箔を得る工程と、負極活物質上のポリマー電解質層を正極活物質のポリマー電解質層に密着させて負極活物質を正極活物質に対向させかつ短冊状負極集電体箔の一方の側縁が帯状の正極集電体箔の一方の側縁から突出し帯状の正極集電体箔の他方の側縁が短冊状負極集電体箔の他方の側縁から突出するように複数の短冊状負極集電体箔を所定のピッチで帯状の正極集電体箔上に配置する工程と、帯状の正極集電体箔を短冊状負極集電体箔が配置されていないところで交互に折曲げて帯状の正極集電体箔を折り畳む工程と、帯状の正極集電体箔の一方の側縁から突出して積層された複数の短冊状負極集電体箔の突出部に負極端子の一端を設ける工程と、複数の短冊状負極集電体箔の他方の側縁から突出して交互に折り畳まれた帯状の正極集電体箔の突出部に正極端子の一端を設ける工程と、正極端子の他端及び負極端子の他端がそれぞれ外部に表出するように折畳まれた帯状の正極集電体箔を複数の短冊状負極集電体箔とともにパッケージシートで密封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。
【０００６】
この請求項１及び請求項２に係る発明では、帯状の負極集電体箔１４又は帯状の正極集電体箔を折畳むので、放電容量を拡大してもその大きさを拡大することはない。折畳み面積に相応した面積を有する複数の短冊状正極集電体箔１２又は短冊状負極集電体箔をポリマー電解質層１７の間にそれぞれ挟持させるので、折目部分に撓みが生じることを防止し、撓みに起因する内部ショートを防止する。また、ポリマー電解質層１７は帯状の負極集電体箔１５の負極活物質１６の表面又は帯状の正極集電体箔の正極活物質の表面に形成されるので、そのポリマー電解質層１７の間に挟持された複数の短冊状正極集電体箔１２における正極活物質１３又は短冊状負極集電体箔における負極活物質はそれぞれ同一の電解質を共有していることになり、各活物質間の内部インピーダンスが均一化してサイクル特性を向上させることができる。
【０００７】
【発明の実施の形態】
次に本発明の実施の形態を図面に基づいて詳しく説明する。
図１に示すように、リチウムイオンポリマー二次電池１０は、正極シート１１と負極シート１４との間にポリマー電解質層１７を介装し、その正極シート１１及び負極シート１４を積層したものである。正極シート１１は正極集電体箔１２の表面に活物質１３が形成されたものであり、負極シート１４は負極集電体箔１５の表面に活物質１６が形成されたものである。また、ポリマー電解質層１７は正極集電体箔１２に形成された活物質１３と負極集電体箔１５の表面に形成された活物質１６との間に介装される。このリチウムイオンポリマー二次電池１０は、放電容量を拡大するために帯状の負極集電体箔１５を用い、その帯状の負極集電体箔１５は活物質表面１６にポリマー電解質層１７を有した状態で折畳まれる。なお、この実施の形態における負極集電体箔１５はＣｕ箔であり、負極集電体箔１５の活物質１６にはグラファイト系の活物質が使用される。
【０００８】
図６（ａ）及び（ｂ）に示すように、活物質１６の負極集電体箔１５の表面への具体的な形成手順は、活物質を溶液に分散混合して作製したスラリーを帯状の負極集電体箔１５の上面にドクターブレード法により塗布して乾燥することにより行われる。一方、活物質１６は他方の側部を除いて表面である図における負極集電体箔１５の上面に形成され、ポリマー電解質層１７はその活物質１６の上面に電解質スラリーを塗布乾燥することにより作られる。ポリマー電解質層１７はこの活物質１６を被覆する面積を有するように形成される。具体的には、図６（ｃ）に示すように、電解質スラリーを活物質１６を覆うように塗布し、その後乾燥することにより活物質１６を被覆する面積に形成される。
図１に戻って、リチウムイオンポリマー二次電池１０は、折畳まれた負極シート１４の折目を除くポリマー電解質層１７の間にそれぞれ折畳み面積に相応した面積を有する複数の正極シート１１が挟持される。挟持される正極シート１１の活物質１３の表面にもポリマー電解質層１７が形成される、この実施の形態における正極集電体箔１２はＡｌ箔であり、活物質１３には例えばＬｉＣｏＯ₂が使用される。
具体的な正極シート１１の作製手順は、図５（ａ）及び（ｂ）に示すように、活物質を溶液に分散混合したスラリーをドクターブレード法により塗布して乾燥することにより後に正極集電体箔になる帯状のＡｌ箔１８の上面に先ず活物質１３を形成する。活物質１３はＡｌ箔１８の一方の側部を除いて形成され、ポリマー電解質層１７はこの活物質１３を被覆する面積を有するように形成される。具体的には、図５（ｃ）に示すように、電解質スラリーは活物質１３を覆うように塗布し、その後乾燥することにより活物質１３を被覆する面積に形成される。その後図５（ｄ）に示すように、活物質１３及びポリマー電解質層１７を有する帯状のＡｌ箔１８は、その活物質１３及びポリマー電解質層１７とともに負極シート１４の折畳み面積に相応した面積を有するように切断される。これにより、正極集電体箔１２の表面に活物質１３が形成され、その活物質１３表面にポリマー電解質層１７を有する所定の面積の正極シート１１が複数枚作られる。
【０００９】
次いで図４に示すように、ポリマー電解質層１７を間に介装して正極シート１１及び負極シート１４が積層される。この積層は熱圧着により行われる。即ち、負極シート１４に折目の間隔に相応する所定のピッチで複数の正極シート１１を配置し、その状態で所定の温度に加熱された反対方向にそれぞれ回転する一対のローラ１９，１９間に図の実線矢印に示すように通過させ、ポリマー電解質層１７を介装した状態で正極シート１１及び負極シート１４を熱圧着する。複数の正極シート１１の負極シート１４上への配置は、帯状の負極集電体箔１５の他方の側縁１５ｂが複数の正極集電体箔１２の他方の側縁１２ｂから突出し、複数の正極集電体箔１２の一方の側縁１２ａがその帯状の負極集電体箔１５の一方の側縁１５ａから突出するように、またそれぞれの正極シート１１が負極シート１４の折目に相当する部分をあけて配置される。
【００１０】
図３に示すように、このように正極シート１１が積層された負極シート１４の折畳みは、正極シート１１が配置されていない負極シート１４の折目を交互に折曲げることにより行われる。このように折畳むと、帯状の負極集電体箔１５の他方の側縁１５ｂは複数の正極集電体箔１２の他方の側縁１２ｂから突出し、複数の正極集電体箔１２の一方の側縁１２ａは帯状の負極集電体箔１５の一方の側縁１５ａから突出した状態で積層される。図１に示すように、このように折畳まれた負極シート１４の折目を除くポリマー電解質層１７の間には、それぞれ折畳み面積に相応した面積を有する複数の正極シート１１が挟持される。一方、図２及び図３に示すように、複数の正極集電体箔１２の他方の側縁１２ｂから突出した負極集電体箔１５の複数の突出部１５ｃにはこの突出部１５ｃを相互に接続する負極端子２１の一端が止め金具２２により設けられ、負極集電体箔１５の一方の側縁１５ａから突出した正極集電体箔１２の複数の突出部１２ｃにはこの突出部１２ｃを相互に接続する正極端子２３の一端が止め金具２２により設けられる。
【００１１】
図１及び図２に示すように、このように折畳まれた帯状の負極シート１４は複数の正極シート１１とともにパッケージシート２４で密封される。この実施の形態におけるパッケージシート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であり、一対のパッケージシート２４で折畳まれた帯状の負極シート１４を複数の正極シート１１とともに挟み、真空雰囲気中でパッケージシート２４の周囲を熱圧着することにより密封される。一対のパッケージシート２４は正極端子２３の他端及び負極端子２１の他端がそれぞれそのパッケージシート２４の外部に表出するように周囲が熱圧着され、このようにして作ら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２４から引出された正極及び負極端子２１，２３の他端を電池の端子として使用することにより所望の電気を得ることができる。
【００１２】
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は、面積を拡大させた帯状の負極シート１４を折畳むので、比較的小型薄型の状態のまま放電容量を拡大できる。また、折畳み面積に相応した面積を有する複数の正極シート１１をポリマー電解質層１７の間にそれぞれ挟持させるので、折目部分における正極シート１１又は負極シート１４に撓みが生じることはない。このため、正極シート１１又は負極シート１４が撓むことにより生じうる内部ショートを確実に防止することができる。
また、挟持される正極シート１１の活物質１３の表面にポリマー電解質層１７を予め形成するので、ポリマー電解質層１７を介装して正極シート１１及び負極シート１４が積層した状態における内部抵抗を減少させることができる。また、ポリマー電解質層１７が正極シート１１及び負極シート１４のそれぞれ活物質１３，１６を被覆する面積を有するようにしたので、有効電極面積が増大して内部抵抗を更に減少させることができる。更に、乾燥しやすい活物質の端部を被覆するポリマー電解質層１７がその端部に生じる内部抵抗の増加を抑制させて放電容量のサイクル特性及び高率充放電特性を向上することができる。
【００１３】
なお、上述した実施の形態では、活物質１３，１６及びポリマー電解質層１７を負極及び正極集電体箔１２，１５の表面である一方の面に塗布乾燥し、帯状の負極シート１４の一方の面に所定のピッチで複数の正極シート１１を熱圧着して正極シート１１が配置されていない負極シート１４の折目を交互に折曲げたが、図８に示すように、活物質１３，１６及びポリマー電解質層１７を負極及び正極集電体箔１２，１５の上下の双方の面にそれぞれ塗布乾燥した帯状の負極シート１４の上下の双方の面に所定のピッチで複数の正極シート１１を熱圧着し、図７に示すように、正極シート１１が配置されていない負極シート１４の折目を交互に折曲げたリチウムイオンポリマー二次電池であってもよい。図７に示すように、負極及び正極集電体箔１２，１５の表面である両面に活物質１３，１６及びポリマー電解質層１７をそれぞれ塗布乾燥した帯状の負極又は正極シート１４、１１を交互に折曲げれば、負極シート１４と正極シート１１が交互に積層されるためリチウムイオンポリマー二次電池のエネルギー密度を向上することができる。この場合、ポリマー電解質層は二層となるが、電池の積層数が３以上の場合には、サイクル特性が向上するという効果を発揮できる。
【００１４】
また、上述した実施の形態では、帯状の負極シート１４を折畳む場合を示したが、図示しないが、帯状の正極シートをポリマー電解質層を有した状態で１又は２回以上折畳み、折畳まれた正極シートの折目を除くポリマー電解質層の間にそれぞれ折畳み面積に相応した面積を有する複数の負極シートを挟持してもよい。この場合、上述した実施の形態では、挟持される正極シート１１がその活物質１３表面にポリマー電解質層１７を有する場合を説明したが、このように、帯状の正極シートを折畳む場合には、挟持される負極シートの活物質表面にポリマー電解質層が形成される。
【００１５】
【実施例】
次に本発明の実施例を説明する。
＜実施例１＞
先ず複数枚の正極シート１１を作製した。即ち、ＬｉＣｏＯ₂粉末７０ｇと黒鉛粉末（商品名；ケッチェンブラック）４ｇ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スラリーを作製した。一方、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）４０ｇをジメチルカーボネート２００ｇに６０℃で溶解し、更に電解液８０ｇを撹拌混合して電解質スラリーを作製した。次に、幅１０ｃｍ長さが１ｍのＡｌ箔の上面に、活物質を分散混合したスラリーをドクターブレード法により塗布及び乾燥し、更にその活物質１３を覆うように電解質スラリーを塗布及び乾燥した。乾燥して活物質１３及びポリマー電解質層１７が形成された帯状のＡｌ箔をその活物質１３及びポリマー電解質層１７とともに切断して幅が１０ｃｍ長さが１０ｃｍの１０枚の正極シート１１を得た。
【００１６】
次に帯状の負極シート１４を作製した。即ち、燐片状天然黒鉛粉末５０ｇ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スラリーを幅１０ｃｍ長さが１ｍのＣｕ箔の上面にドクターブレード法により塗布及び乾燥した後、上述した電解質スラリーを更にその活物質１３を覆うように塗布及び乾燥して帯状の負極シート１４を作製した。この帯状の負極シート１４に折目の間隔に相応する所定のピッチで複数の正極シート１１を熱圧着して正極シート１１が配置されていない負極シート１４の折目を交互に折曲げ、幅１０ｃｍ長さ１０ｃｍの折畳み面積を有する帯状の負極シート１４のポリマー電解質層１７の間にそれぞれ幅１０ｃｍ長さ１０ｃｍの１０枚の正極シート１１が挟持されたリチウムイオンポリマー二次電池を得た。この電池を実施例１とした。
【００１７】
＜比較例１＞
実施例１と同一の手順で１０枚の正極シートを作製した。次に実施例１と同一の手順により得られた帯状の負極シートを切断して幅が１０ｃｍ長さが１０ｃｍの１０枚の負極シートを得た。次に単一の負極シート１４を単一の正極シートにポリマー電解質層を介してそれぞれ熱圧着して１０組の積層体を作製した。この１０組の積層体を更に積層して正極シートと負極シートの対抗面積が実施例１と略同一のリチウムイオンポリマー二次電池を得た。この電池を比較例１とした。
【００１８】
＜比較試験＞
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放電容量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９に示す。
【００１９】
＜評価＞
図９の結果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の放電容量のサイクル特性は比較例１のサイクル特性より向上していることが判る。これは、比較例１の１０枚の正極シート１１における活物質はそれぞれ異なる電解質を有しているのに対し、実施例１の１０枚の正極シート１１における活物質はそれぞれ同一の電解質を共有したことに起因するものと考えられる。
【００２０】
【発明の効果】
以上述べたように、本発明によれば、放電容量を拡大するために面積を拡大させた帯状の正極又は負極シートを折畳むので、比較的小型薄型の状態のまま放電容量を拡大できる。また、折畳み面積に相応した面積を有する複数の負極又は正極シートをポリマー電解質層の間にそれぞれ挟持させたので、折目部分における正極シート又は負極シートに撓みが生じることはなく、正極シート又は負極シートが撓むことにより生じうる内部ショートを防止することができる。また、ポリマー電解質層を帯状の正極シート又は負極シートに形成するので、そのポリマー電解質層の間に挟持された複数の負極シート又は正極シートにおける活物質はそれぞれ同一の電解質を共有していることになり、各活物質間の内部インピーダンスが均一化してサイクル特性を向上することができる。
【００２１】
また、挟持される負極シート又は正極シートの活物質表面にポリマー電解質層を形成すれば、それぞれのポリマー電解質層形成時に活物質への拡散効果により内部抵抗を減少させることができ、ポリマー電解質層が活物質を被覆する面積を有していれば、有効電極面積が増大して内部抵抗を更に減少させ、被覆するポリマー電解質層が活物質の端部における乾燥を防止して経時変化に伴う内部抵抗の増加を防ぐ。この結果、放電容量のサイクル特性及び高率充放電特性を向上することができる。
【００２２】
更に、正極シートの複数の突出部を相互に接続するように正極端子を設け、負極シートの複数の突出部を相互に接続するように負極端子を設ければ、それぞれの活物質における電位差を電流として取出すための正極端子及び負極端子を設ける作業が単純になり、いわゆる低コストで高容量のリチウムイオンポリマー二次電池を得ることができる。
【図面の簡単な説明】
【図１】本発明の二次電池を示す図２のＡ−Ａ線断面図。
【図２】その二次電池を示す図１のＢ−Ｂ線断面図。
【図３】その二次電池の構成を示す分解斜視図。
【図４】その負極シートに正極シートが熱圧着される状態を示す斜視図。
【図５】その正極シートの製造工程を示す図。
【図６】その負極シートの製造工程を示す図。
【図７】本発明の別の二次電池を示す図１に対応する断面図。
【図８】その別の二次電池の負極シートに正極シートが熱圧縮される状態を示す図４に対応する断面図。
【図９】本発明実施例の放電容量のサイクル特性を示す図。
【符号の説明】
１０リチウムイオンポリマー二次電池
１１正極シート
１２正極集電体箔
１２ａ一方の側縁
１２ｂ他方の側縁
１２ｃ突出部
１３活物質
１４負極シート
１５負極集電体箔
１５ａ一方の側縁
１５ｂ他方の側縁
１５ｃ突出部
１６活物質
１７ポリマー電解質層
２１負極端子
２３正極端子[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a lithium ion polymer secondary battery in which a positive electrode sheet and a negative electrode sheet are laminated via a polymer electrolyte layer.
[0002]
[Prior art]
Due to the spread of portable devices such as video cameras and notebook computers in recent years, the demand for thin batteries has increased. As this thin battery, a lithium ion polymer secondary battery formed by laminating a positive electrode sheet and a negative electrode sheet is known. The positive electrode sheet is made by forming an active material on the surface of the positive electrode current collector foil, and the negative electrode sheet is made by forming an active material on the surface of the negative electrode current collector foil. A polymer electrolyte layer is interposed between the active material of the positive electrode sheet and the active material of the negative electrode sheet. In this battery, a positive electrode terminal and a negative electrode terminal for taking out a potential difference in each active material as a current are provided on the positive electrode current collector foil and the negative electrode current collector foil, and the stacked ones are sealed with a package. Thus, a lithium ion polymer secondary battery is formed. In this lithium ion polymer secondary battery, desired electricity can be obtained by using a positive electrode terminal and a negative electrode terminal drawn out of the package as terminals of the battery.
[0003]
[Problems to be solved by the invention]
However, in order to increase the discharge capacity of the lithium ion polymer secondary battery, it is necessary to enlarge the areas of the positive electrode sheet and the negative electrode sheet. A simple enlargement of the area of the positive electrode sheet and the negative electrode sheet results in a battery having a relatively large area although it is thin. In order to eliminate this point, it is conceivable to fold the expanded positive electrode sheet and negative electrode sheet to a desired size. However, when the positive electrode sheet and the negative electrode sheet are folded, the positive electrode sheet or the negative electrode sheet is bent at the fold portion, and the sheet at that portion peels off from the electrolyte layer, reducing the effective surface area of the electrode / electrolyte interface. As a result, the discharge capacity is reduced, and resistance is caused inside the battery to deteriorate the cycle characteristics of the discharge capacity. In addition, when the deflection is relatively large, there is also a problem that a so-called internal short circuit occurs in which the positive electrode sheet and the negative electrode sheet are in direct contact with each other.
An object of the present invention is to provide a lithium ion polymer secondary battery that can reliably prevent internal short-circuits to increase discharge capacity and improve cycle characteristics of discharge capacity.
[0004]
[Means for Solving the Problems]
The invention according to claim 1 is a polymer electrolyte layer in which a positive electrode active material 13 and a positive electrode active material 13 are coated on the surface excluding one side of a belt-like positive electrode current collector foil 18 as shown in FIGS. 17 in this order, and a process in which the negative electrode active material 16 and the polymer electrolyte layer 17 covering the negative electrode active material 16 are formed in this order on the surface excluding the other side of the strip-shaped negative electrode current collector foil 15. Cutting the strip-shaped positive electrode current collector foil 18 together with the positive electrode active material 13 and the polymer electrolyte layer 17 into a predetermined length to obtain a plurality of strip-shaped positive electrode current collector foils 12; The polymer electrolyte layer 17 is closely attached to the polymer electrolyte layer 17 on the negative electrode active material 13, the positive electrode active material 13 is opposed to the negative electrode active material 16, and one side edge 12a of the strip-shaped positive electrode current collector foil 12 is a strip-shaped negative electrode From one side edge 15a of the current collector foil 15 The strip-shaped positive electrode current collector foils 12 are arranged at a predetermined pitch so that the other side edge 15b of the strip-shaped negative electrode current collector foil 15 protrudes from the other side edge 12b of the strip-shaped positive electrode current collector foil 12. The step of disposing on the strip-shaped negative electrode current collector foil 14 and the strip-shaped negative electrode current collector foil 15 are alternately folded where the strip-shaped positive electrode current collector foil 12 is not disposed, thereby forming the strip-shaped negative electrode current collector foil 14 and a step of providing one end of the positive electrode terminal 23 on the protruding portion 12c of the plurality of strip-shaped positive electrode current collector foils 12 protruding from one side edge 15a of the strip-shaped negative electrode current collector foil 15; A step of providing one end of the negative electrode terminal 21 on the protruding portion 15c of the strip-shaped negative electrode current collector foil 15 protruding from the other side edge 12b of the plurality of strip-shaped positive electrode current collector foils 12 and being alternately folded; 23 and the other end of the negative terminal 21 are exposed to the outside. A method for producing a lithium polymer battery and a step of sealing the strip-shaped anode current collector foil 15 folded so that together with a plurality of strip-shaped positive electrode current collector foil 12 in the package sheet 24.
[0005]
According to a second aspect of the present invention, there is provided a step of forming a negative electrode active material and a polymer electrolyte layer covering the negative electrode active material in this order on a surface excluding one side portion of the strip-shaped negative electrode current collector foil; A step of forming a positive electrode active material and a polymer electrolyte layer covering the positive electrode active material in this order on the surface excluding the other side portion of the electric foil, and a strip-shaped negative electrode current collector foil together with the negative electrode active material and the polymer electrolyte layer A process of obtaining a plurality of strip-shaped negative electrode current collector foils by cutting to a predetermined length, and a polymer electrolyte layer on the negative electrode active material being closely adhered to the polymer electrolyte layer of the positive electrode active material to make the negative electrode active material a positive electrode active material Opposite and one side edge of the strip-shaped negative electrode current collector foil protrudes from one side edge of the strip-shaped positive electrode current collector foil, and the other side edge of the strip-shaped positive electrode current collector foil is the strip-shaped negative electrode current collector foil A plurality of strip-like negative electrode current collector foils so as to protrude from the other side edge of the A strip-shaped positive electrode current collector foil, and a strip-shaped positive electrode current collector foil by alternately bending the strip-shaped positive electrode current collector foil where the strip-shaped negative electrode current collector foil is not disposed. A step of providing one end of a negative electrode terminal on a protruding portion of a plurality of strip-shaped negative electrode current collector foils protruding from one side edge of a belt-like positive electrode current collector foil, and a plurality of strip-shaped negative electrodes A step of providing one end of the positive electrode terminal at the protruding portion of the strip-shaped positive electrode current collector foil protruding from the other side edge of the current collector foil, and the other end of the positive electrode terminal and the other end of the negative electrode terminal, respectively And a step of sealing a strip-shaped positive electrode current collector foil folded so as to be exposed to the outside together with a plurality of strip-shaped negative electrode current collector foils with a package sheet .
[0006]
In the inventions according to claims 1 and 2, since the strip-shaped negative electrode current collector foil 14 or the strip-shaped positive electrode current collector foil is folded, the size thereof is not expanded even if the discharge capacity is expanded. . Since a plurality of strip-shaped positive electrode current collector foils 12 or strip-shaped negative electrode current collector foils having an area corresponding to the folding area are sandwiched between the polymer electrolyte layers 17, it is possible to prevent the bending portion from being bent. Prevents internal short circuit due to bending. Further, since the polymer electrolyte layer 17 is formed on the surface of the negative electrode active material 16 of the strip-shaped negative electrode current collector foil 15 or the surface of the positive electrode active material of the strip-shaped positive electrode current collector foil 15, the polymer electrolyte layer 17 is interposed between the polymer electrolyte layers 17. The positive electrode active material 13 in the sandwiched plurality of strip-shaped positive electrode current collector foils 12 or the negative electrode active material in the strip-shaped negative electrode current collector foils share the same electrolyte, and the inside of each active material Impedance can be made uniform and cycle characteristics can be improved.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1, a lithium ion polymer secondary battery 10 is obtained by interposing a polymer electrolyte layer 17 between a positive electrode sheet 11 and a negative electrode sheet 14 and laminating the positive electrode sheet 11 and the negative electrode sheet 14. . The positive electrode sheet 11 has an active material 13 formed on the surface of the positive electrode current collector foil 12, and the negative electrode sheet 14 has an active material 16 formed on the surface of the negative electrode current collector foil 15. The polymer electrolyte layer 17 is interposed between the active material 13 formed on the positive electrode current collector foil 12 and the active material 16 formed on the surface of the negative electrode current collector foil 15. The lithium ion polymer secondary battery 10 uses a strip-shaped negative electrode current collector foil 15 to expand the discharge capacity, and the strip-shaped negative electrode current collector foil 15 has a polymer electrolyte layer 17 on the active material surface 16. Folded in state. The negative electrode current collector foil 15 in this embodiment is a Cu foil, and a graphite-based active material is used for the active material 16 of the negative electrode current collector foil 15.
[0008]
As shown in FIGS. 6A and 6B, the specific formation procedure of the active material 16 on the surface of the negative electrode current collector foil 15 is a strip-like slurry prepared by dispersing and mixing the active material in a solution. It is carried out by applying and drying on the upper surface of the negative electrode current collector foil 15 by a doctor blade method. On the other hand, the active material 16 is formed on the upper surface of the negative electrode current collector foil 15 in the figure which is the surface except for the other side portion , and the polymer electrolyte layer 17 is formed by applying and drying an electrolyte slurry on the upper surface of the active material 16. Made. The polymer electrolyte layer 17 is formed so as to have an area covering the active material 16. Specifically, as shown in FIG. 6C, an electrolyte slurry is applied so as to cover the active material 16, and then dried to form an area covering the active material 16.
Returning to FIG. 1, in the lithium ion polymer secondary battery 10, a plurality of positive electrode sheets 11 each having an area corresponding to the folded area are sandwiched between the polymer electrolyte layers 17 excluding the folds of the folded negative electrode sheet 14. Is done. The polymer electrolyte layer 17 is also formed on the surface of the active material 13 of the sandwiched positive electrode sheet 11. The positive electrode current collector foil 12 in this embodiment is an Al foil, and the active material 13 is made of, for example, LiCoO _2. Is done.
As shown in FIGS. 5A and 5B, a specific procedure for producing the positive electrode sheet 11 is as follows. A slurry obtained by dispersing and mixing an active material in a solution is applied by a doctor blade method and dried to later collect a positive electrode current. First, the active material 13 is formed on the upper surface of the strip-shaped Al foil 18 that becomes the body foil. The active material 13 is formed except for one side portion of the Al foil 18, and the polymer electrolyte layer 17 is formed to have an area covering the active material 13. Specifically, as shown in FIG. 5C, the electrolyte slurry is formed in an area covering the active material 13 by applying the electrolyte slurry so as to cover the active material 13 and then drying. Thereafter, as shown in FIG. 5 (d), the strip-shaped Al foil 18 having the active material 13 and the polymer electrolyte layer 17 has an area corresponding to the folded area of the negative electrode sheet 14 together with the active material 13 and the polymer electrolyte layer 17. So that it is cut. Thereby, the active material 13 is formed on the surface of the positive electrode current collector foil 12, and a plurality of positive electrode sheets 11 having a predetermined area having the polymer electrolyte layer 17 on the surface of the active material 13 are produced.
[0009]
Next, as shown in FIG. 4, the positive electrode sheet 11 and the negative electrode sheet 14 are laminated with the polymer electrolyte layer 17 interposed therebetween. This lamination is performed by thermocompression bonding. That is, a plurality of positive electrode sheets 11 are arranged on the negative electrode sheet 14 at a predetermined pitch corresponding to the interval between the folds, and in this state, a pair of rollers 19 and 19 are rotated in opposite directions and heated to a predetermined temperature. The positive electrode sheet 11 and the negative electrode sheet 14 are subjected to thermocompression bonding with the polymer electrolyte layer 17 interposed, as shown by solid line arrows in the figure. The arrangement of the plurality of positive electrode sheets 11 on the negative electrode sheet 14 is such that the other side edge 15b of the strip-shaped negative electrode current collector foil 15 protrudes from the other side edge 12b of the plurality of positive electrode current collector foils 12 , A portion in which one side edge 12 a of the current collector foil 12 protrudes from one side edge 15 a of the strip-shaped negative electrode current collector foil 15, and each positive electrode sheet 11 corresponds to a fold of the negative electrode sheet 14. It is arranged with a gap.
[0010]
As shown in FIG. 3, the folding of the negative electrode sheet 14 on which the positive electrode sheet 11 is laminated in this way is performed by alternately folding the folds of the negative electrode sheet 14 on which the positive electrode sheet 11 is not disposed. When folded in this way, the other side edge 15b of the strip-shaped negative electrode current collector foil 15 protrudes from the other side edge 12b of the plurality of positive electrode current collector foils 12, and The side edge 12 a is laminated in a state of protruding from one side edge 15 a of the strip-shaped negative electrode current collector foil 15. As shown in FIG. 1, a plurality of positive electrode sheets 11 each having an area corresponding to a folded area are sandwiched between polymer electrolyte layers 17 excluding the folds of the negative electrode sheet 14 thus folded. On the other hand, as shown in FIGS. 2 and 3, the protrusions 15c of the negative current collector foil 15 protruding from the other side edge 12b of the positive current collector foils 12 are connected to each other. One end of the negative electrode terminal 21 to be connected is provided by the stopper 22, and the protrusions 12 c of the positive electrode current collector foil 12 protruding from one side edge 15 a of the negative electrode current collector foil 15 are connected to each other. One end of a positive electrode terminal 23 connected to is provided by a fastener 22.
[0011]
As shown in FIGS. 1 and 2, the band-shaped negative electrode sheet 14 folded in this way is sealed together with a plurality of positive electrode sheets 11 by a package sheet 24. The package sheet 24 in this embodiment is an aluminum foil laminated with polypropylene, and a strip-like negative electrode sheet 14 folded between a pair of package sheets 24 is sandwiched together with a plurality of positive electrode sheets 11, and the package sheet 24 in a vacuum atmosphere. Is sealed by thermocompression bonding. The pair of package sheets 24 are thermocompression-bonded so that the other end of the positive electrode terminal 23 and the other end of the negative electrode terminal 21 are exposed to the outside of the package sheet 24, respectively. The secondary battery 10 can obtain desired electricity by using the other ends of the positive and negative terminals 21 and 23 drawn from the package sheet 24 as battery terminals.
[0012]
Since the lithium ion polymer secondary battery 10 configured in this manner folds the strip-shaped negative electrode sheet 14 having an enlarged area, the discharge capacity can be increased while being relatively small and thin. In addition, since the plurality of positive electrode sheets 11 having an area corresponding to the folding area are sandwiched between the polymer electrolyte layers 17, the positive electrode sheet 11 or the negative electrode sheet 14 at the fold portion does not bend. For this reason, the internal short circuit which may arise when the positive electrode sheet 11 or the negative electrode sheet 14 bends can be prevented reliably.
In addition, since the polymer electrolyte layer 17 is formed in advance on the surface of the active material 13 of the sandwiched positive electrode sheet 11, the internal resistance in a state where the positive electrode sheet 11 and the negative electrode sheet 14 are laminated with the polymer electrolyte layer 17 interposed therebetween is reduced. Can be made. Further, since the polymer electrolyte layer 17 has an area covering the active material 13 and 16 of the positive electrode sheet 11 and the negative electrode sheet 14, respectively, the effective electrode area can be increased and the internal resistance can be further reduced. Furthermore, the polymer electrolyte layer 17 covering the end portion of the active material that is easily dried can suppress an increase in internal resistance generated at the end portion, thereby improving the cycle characteristics and the high rate charge / discharge characteristics of the discharge capacity.
[0013]
In the above-described embodiment, the active materials 13 and 16 and the polymer electrolyte layer 17 are applied and dried on one surface which is the surface of the negative electrode and the positive electrode current collector foils 12 and 15, and one of the strip-shaped negative electrode sheet 14 is dried. A plurality of positive electrode sheets 11 were thermocompression-bonded on the surface at a predetermined pitch, and the folds of the negative electrode sheets 14 on which the positive electrode sheets 11 were not disposed were alternately bent. As shown in FIG. And the polymer electrolyte layer 17 is applied to both the upper and lower surfaces of the negative electrode and the positive electrode current collector foils 12 and 15, respectively. As shown in FIG. 7, a lithium ion polymer secondary battery in which the folds of the negative electrode sheet 14 on which the positive electrode sheet 11 is not disposed is alternately folded may be used. As shown in FIG. 7, strip-like negative electrode or positive electrode sheets 14 and 11 in which active materials 13 and 16 and polymer electrolyte layer 17 are applied and dried on both surfaces of the negative electrode and positive electrode current collector foils 12 and 15, respectively, are alternately arranged. If bent, the negative electrode sheet 14 and the positive electrode sheet 11 are alternately laminated, so that the energy density of the lithium ion polymer secondary battery can be improved. In this case, the polymer electrolyte layer has two layers, but when the number of battery stacks is three or more, the effect of improving the cycle characteristics can be exhibited.
[0014]
Moreover, although the case where the strip-shaped negative electrode sheet 14 is folded is shown in the above-described embodiment, although not shown, the strip-shaped positive electrode sheet is folded one or more times with the polymer electrolyte layer and folded. A plurality of negative electrode sheets each having an area corresponding to the folded area may be sandwiched between the polymer electrolyte layers excluding the folds of the positive electrode sheet. In this case, in the above-described embodiment, the case where the positive electrode sheet 11 to be sandwiched has the polymer electrolyte layer 17 on the surface of the active material 13 has been described. Thus, when the belt-shaped positive electrode sheet is folded, A polymer electrolyte layer is formed on the surface of the active material of the sandwiched negative electrode sheet .
[0015]
【Example】
Next, examples of the present invention will be described.
<Example 1>
First, a plurality of positive electrode sheets 11 were produced. That is, 70 g of LiCoO ₂ powder and 4 g of graphite powder (trade name; Ketjen Black) were dispersed and mixed in an N-methylpyrrolidone solution of polyvinylidene fluoride to prepare a slurry. On the other hand, 40 g of vinylidene fluoride-hexafluoropropylene copolymer (manufactured by Elf Atchem, Kynar 2810; containing 12 wt% hexafluoropropylene) is dissolved in 200 g of dimethyl carbonate at 60 ° C., and 80 g of electrolyte solution is stirred and mixed to obtain an electrolyte slurry. Produced. Next, the slurry in which the active material was dispersed and mixed was applied and dried on the upper surface of the Al foil having a width of 10 cm and a length of 1 m by the doctor blade method, and the electrolyte slurry was further applied and dried so as to cover the active material 13. The strip-shaped Al foil on which the active material 13 and the polymer electrolyte layer 17 were formed by drying was cut together with the active material 13 and the polymer electrolyte layer 17 to obtain ten positive electrode sheets 11 having a width of 10 cm and a length of 10 cm. .
[0016]
Next, a strip-shaped negative electrode sheet 14 was produced. That is, a slurry obtained by dispersing and mixing 50 g of flake-like natural graphite powder in an N-methylpyrrolidone solution of polyvinylidene fluoride was applied to the upper surface of a Cu foil having a width of 10 cm and a length of 1 m by a doctor blade method and then dried. The electrolyte slurry was further applied so as to cover the active material 13 and dried to prepare a strip-shaped negative electrode sheet 14. A plurality of positive electrode sheets 11 are thermocompression-bonded to the strip-shaped negative electrode sheet 14 at a predetermined pitch corresponding to the interval between the folds, and the folds of the negative electrode sheet 14 on which the positive electrode sheet 11 is not disposed are alternately bent, and the width is 10 cm A lithium ion polymer secondary battery was obtained in which ten positive electrode sheets 11 each having a width of 10 cm and a length of 10 cm were sandwiched between the polymer electrolyte layers 17 of the strip-shaped negative electrode sheet 14 having a folded area of 10 cm in length. This battery was referred to as Example 1.
[0017]
<Comparative Example 1>
Ten positive electrode sheets were produced in the same procedure as in Example 1. Next, the strip-shaped negative electrode sheet obtained by the same procedure as in Example 1 was cut to obtain 10 negative electrode sheets having a width of 10 cm and a length of 10 cm. Next, the single negative electrode sheet 14 was thermocompression bonded to the single positive electrode sheet via the polymer electrolyte layer to produce 10 sets of laminates. These 10 sets of laminates were further laminated to obtain a lithium ion polymer secondary battery in which the opposing areas of the positive electrode sheet and the negative electrode sheet were substantially the same as those in Example 1. This battery was referred to as Comparative Example 1.
[0018]
<Comparison test>
The cycle characteristics of the discharge capacity of the lithium ion polymer secondary batteries of Example 1 and Comparative Example 1 were measured with a charge / discharge tester. The result is shown in FIG.
[0019]
<Evaluation>
As is clear from the results of FIG. 9, the gradient in the cycle characteristics of the lithium ion polymer secondary battery in Example 1 is gentler than the gradient in Comparative Example 1, and the cycle characteristics of the discharge capacity in Example 1 are It can be seen that the cycle characteristics of Comparative Example 1 are improved. This is because the active materials in the ten positive electrode sheets 11 of Comparative Example 1 have different electrolytes, whereas the active materials in the ten positive electrode sheets 11 of Example 1 shared the same electrolyte. This is thought to be caused by this.
[0020]
【The invention's effect】
As described above, according to the present invention, since the strip-like positive electrode or negative electrode sheet having an enlarged area is folded in order to increase the discharge capacity, the discharge capacity can be increased while maintaining a relatively small and thin state. In addition, since a plurality of negative electrodes or positive electrode sheets having an area corresponding to the folding area are sandwiched between the polymer electrolyte layers, the positive electrode sheet or the negative electrode sheet in the fold portion is not bent, and the positive electrode sheet or the negative electrode sheet It is possible to prevent an internal short circuit that may occur when the sheet is bent. In addition, since the polymer electrolyte layer is formed on the belt-like positive electrode sheet or negative electrode sheet, the active materials in the plurality of negative electrode sheets or positive electrode sheets sandwiched between the polymer electrolyte layers share the same electrolyte. Thus, the internal impedance between the active materials can be made uniform, and the cycle characteristics can be improved.
[0021]
Further, if a polymer electrolyte layer is formed on the active material surface of the sandwiched negative electrode sheet or positive electrode sheet, the internal resistance can be reduced due to the diffusion effect on the active material when each polymer electrolyte layer is formed, and the polymer electrolyte layer is If the area covering the active material is provided, the effective electrode area is increased to further reduce the internal resistance, and the polymer electrolyte layer to be coated prevents the active material from drying at the end portion, so that the internal resistance with time changes To prevent the increase. As a result, the cycle characteristics and high rate charge / discharge characteristics of the discharge capacity can be improved.
[0022]
Furthermore, if a positive electrode terminal is provided so that a plurality of protrusions of the positive electrode sheet are connected to each other, and a negative electrode terminal is provided so as to connect a plurality of protrusions of the negative electrode sheet to each other, the potential difference in each active material is determined as a current. As a result, the work of providing a positive electrode terminal and a negative electrode terminal for taking out the battery becomes simple, and a so-called low-cost and high-capacity lithium ion polymer secondary battery can be obtained.
[Brief description of the drawings]
1 is a cross-sectional view taken along line AA of FIG. 2 showing a secondary battery of the present invention.
2 is a cross-sectional view taken along the line BB of FIG. 1 showing the secondary battery.
FIG. 3 is an exploded perspective view showing a configuration of the secondary battery.
FIG. 4 is a perspective view showing a state in which a positive electrode sheet is thermocompression bonded to the negative electrode sheet.
FIG. 5 is a view showing a manufacturing process of the positive electrode sheet.
FIG. 6 is a view showing a manufacturing process of the negative electrode sheet.
FIG. 7 is a cross-sectional view corresponding to FIG. 1, showing another secondary battery of the present invention.
FIG. 8 is a cross-sectional view corresponding to FIG. 4 showing a state in which the positive electrode sheet is thermally compressed to the negative electrode sheet of another secondary battery.
FIG. 9 is a diagram showing cycle characteristics of discharge capacity according to an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Lithium ion polymer secondary battery 11 Positive electrode sheet 12 Positive electrode collector foil 12a One side edge 12b The other side edge 12c Protrusion part 13 Active material 14 Negative electrode sheet 15 Negative electrode collector foil 15a One side edge 15b The other side Edge 15c Protrusion 16 Active material 17 Polymer electrolyte layer 21 Negative electrode terminal 23 Positive electrode terminal

Claims

Strip-shaped positive electrode current collector foil (18) Positive electrode active material on the surface excluding one side of (13) And the positive electrode active material (13) Coating polymer electrolyte layer (17) Forming in this order;
  Strip-shaped negative electrode current collector foil (15) Negative electrode active material on the surface excluding the other side of (16) And the negative electrode active material (16) Coating polymer electrolyte layer (17) Forming in this order;
  The strip-shaped positive electrode current collector foil (18) The positive electrode active material (13) And the polymer electrolyte layer (17) A plurality of strip-shaped positive electrode current collector foils cut into a predetermined length together with (12) Obtaining
  The positive electrode active material (16) Top polymer electrolyte layer (17) The negative electrode active material (13) Top polymer electrolyte layer (17) Adhering to the positive electrode active material (13) The negative electrode active material (16) And the strip-shaped positive electrode current collector foil (12) One side edge of (12a) Is said strip-shaped negative electrode current collector foil (15) One side edge of (15a) Projecting from the strip-shaped negative electrode current collector foil (15) Other side edge of (15b) Is the strip-shaped positive electrode current collector foil (12) Other side edge of (12b) A plurality of the strip-shaped positive electrode current collector foils so as to protrude from (12) The strip-shaped negative electrode current collector foil at a predetermined pitch (14) A step of placing on top;
  The strip-shaped negative electrode current collector foil (15) The strip-shaped positive electrode current collector foil (12) The strip-shaped negative electrode current collector foil is alternately bent at a place where no electrode is disposed (14) Folding process,
  The strip-shaped negative electrode current collector foil (15) One side edge of (15a) A plurality of the short positive electrode current collector foils stacked so as to protrude from (12) Protrusion (12c) To positive terminal (twenty three) Providing one end of:
  A plurality of the strip-shaped positive electrode current collector foils (12) Other side edge of (12b) The strip-shaped negative electrode current collector foil which is protruded from and alternately folded (15) Protrusion (15c) To negative terminal (twenty one) Providing one end of:
  The positive terminal (twenty three) And the negative terminal (twenty one) The strip-shaped negative electrode current collector foil is folded so that the other end of each is exposed to the outside (15) A plurality of the strip-shaped positive electrode current collector foil (12) With package sheet (twenty four) Sealing process with
  The manufacturing method of the lithium ion polymer secondary battery containing this.

Forming a negative electrode active material and a polymer electrolyte layer covering the negative electrode active material in this order on the surface excluding one side of the strip-shaped negative electrode current collector foil;
  Forming a positive electrode active material and a polymer electrolyte layer covering the positive electrode active material in this order on the surface excluding the other side of the belt-like positive electrode current collector foil;
  Cutting the strip-shaped negative electrode current collector foil into a predetermined length together with the negative electrode active material and the polymer electrolyte layer to obtain a plurality of strip-shaped negative electrode current collector foils;
  The polymer electrolyte layer on the negative electrode active material is closely adhered to the polymer electrolyte layer of the positive electrode active material so that the negative electrode active material faces the positive electrode active material, and one side edge of the strip-shaped negative electrode current collector foil is A plurality of the strips projecting from one side edge of the strip-shaped positive electrode current collector foil, and the other side edge of the strip-shaped positive electrode current collector foil projecting from the other side edge of the strip-shaped negative electrode current collector foil Arranging the negative electrode current collector foil on the belt-like positive electrode current collector foil at a predetermined pitch;
  Folding the strip-shaped positive electrode current collector foil by alternately folding the strip-shaped positive electrode current collector foil where the strip-shaped negative electrode current collector foil is not disposed;
  A step of providing one end of a negative electrode terminal on the protruding portion of the plurality of strip-shaped negative electrode current collector foils that protrudes from one side edge of the strip-shaped positive electrode current collector foil; and
  A step of providing one end of a positive electrode terminal on the protruding portion of the strip-shaped positive electrode current collector foil protruding alternately from the other side edge of the plurality of strip-shaped negative electrode current collector foils;
  The belt-like positive electrode current collector foil folded so that the other end of the positive electrode terminal and the other end of the negative electrode terminal are exposed to the outside are sealed together with a plurality of the strip-shaped negative electrode current collector foils with a package sheet And the process
  The manufacturing method of the lithium ion polymer secondary battery containing this.