JP2019053825A - Power storage element - Google Patents

Power storage element Download PDF

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JP2019053825A
JP2019053825A JP2017175050A JP2017175050A JP2019053825A JP 2019053825 A JP2019053825 A JP 2019053825A JP 2017175050 A JP2017175050 A JP 2017175050A JP 2017175050 A JP2017175050 A JP 2017175050A JP 2019053825 A JP2019053825 A JP 2019053825A
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electrode
positive electrode
separator
folded
tab
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JP6951682B2 (en
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太郎 山福
Taro Yamafuku
太郎 山福
和輝 川口
Kazuki Kawaguchi
和輝 川口
真規 増田
Masanori Masuda
真規 増田
祥太 伊藤
Shota Ito
祥太 伊藤
亮介 下川
Ryosuke Shimokawa
亮介 下川
謙太 尾木
Kenta Ogi
謙太 尾木
史也 中野
Fumiya Nakano
史也 中野
智典 加古
Tomonori Kako
智典 加古
純 大山
Jun Oyama
純 大山
大聖 関口
Hiromasa Sekiguchi
大聖 関口
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GS Yuasa Corp
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GS Yuasa Corp
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    • 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
    • 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
    • Y02E60/13—Energy storage using capacitors
    • 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

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Abstract

To provide a power storage element in which a member including a second electrode in a folding part of a member including a first electrode which folded in a zigzag is not easily positional deviation.SOLUTION: A power storage element comprises: a long first member 21 that includes a first electrode and is fold in a zigzag so that a first folding part folded at a turn part so as to open one side in a first direction and a second folding part folded at the turn part so as to open the other side in the first direction are alternately distributed; and an electrode body 2 that includes a plurality of second members 22 including a second electrode of which a polarity is different from that of the first polarity and including a second member at the first that is nipped with the first folding part and a second member at the second that is nipped with the second folding part while including the second electrode. An end part of the other side of the second member at the first is contacted to the turn part of the first folding part. The end part of one side of the second member at the second is contacted to the turn part of the second folding part.SELECTED DRAWING: Figure 4

Description

本発明は、電極を有する電極体を備えた蓄電素子に関する。   The present invention relates to a power storage device including an electrode body having electrodes.

従来、正極及び負極の一方が蛇腹状に折り畳まれて積層されているリチウムイオン二次電池（以下、単に「電池」と称する）が知られている（例えば、特許文献１参照）。具体的に、この電池は、図１９に示すように、負極・セパレータ圧着体１２１と正極１２２とを組み合わせて、これを蛇腹状に折り畳んで構成された電極体１０２を備える。   Conventionally, a lithium ion secondary battery (hereinafter simply referred to as “battery”) in which one of a positive electrode and a negative electrode is folded and stacked in a bellows shape is known (see, for example, Patent Document 1). Specifically, as shown in FIG. 19, the battery includes an electrode body 102 configured by combining a negative electrode / separator pressure-bonding body 121 and a positive electrode 122 and folding them in a bellows shape.

負極・セパレータ圧着体１２１は、帯状に連続する一対のセパレータ１２３の間に、負極を基材とする帯状の負極体１２４を圧着して構成されており、全体として帯状に連続している。正極１２２は、複数の短冊状の金属箔を正極リードにより連結して構成されている。   The negative electrode / separator crimped body 121 is configured by crimping a strip-shaped negative electrode body 124 having a negative electrode as a base material between a pair of separators 123 that are continuous in a strip shape, and is continuous in a strip shape as a whole. The positive electrode 122 is configured by connecting a plurality of strip-shaped metal foils with a positive electrode lead.

前記電極体１０２を製造する際には、まず、帯状の一対のセパレータ１２３の間に帯状の負極体１２４を配置して、これらをプレス等により圧着することで、負極・セパレータ圧着体１２１を形成する。さらに、負極・セパレータ圧着体１２１に折り目を形成し、負極・セパレータ圧着体１２１に正極１２２を挿入した後、これを折り目に沿って折り畳むことで前記電極体１０２が製造される。   When the electrode body 102 is manufactured, first, a belt-like negative electrode body 124 is disposed between a pair of belt-like separators 123, and these are pressure-bonded by a press or the like to form a negative electrode / separator pressure-bonded body 121. To do. Furthermore, a crease is formed in the negative electrode / separator crimped body 121, the positive electrode 122 is inserted into the negative electrode / separator crimped body 121, and then the electrode body 102 is folded along the crease.

ところで、前記電極体１０２を備えた電池では、正極１２２の周辺には、挿入方向における正極１２２の負極体１２４に対する相対移動を規制するような構成が何ら存在しないため、正極１２２の負極・セパレータ圧着体１２１に対する相対移動は規制されない。これにより、前記電池では、正極１２２と負極・セパレータ圧着体１２１との相対位置が想定された位置からずれる場合がある。   By the way, in the battery including the electrode body 102, there is no configuration around the positive electrode 122 that restricts the relative movement of the positive electrode 122 with respect to the negative electrode body 124 in the insertion direction. The relative movement with respect to the body 121 is not restricted. Thereby, in the said battery, the relative position of the positive electrode 122 and the negative electrode / separator pressurization body 121 may shift | deviate from the assumed position.

特開２０１３−２２２６０２号公報JP 2013-222602 A

そこで、本実施形態は、つづら折りされた第一の電極を含む部材の折り返し部に第二の電極を含む部材が狭持された蓄電素子であって、第一の電極を含む部材と第二の電極を含む部材とが位置ずれしにくい蓄電素子を提供することを目的とする。   Therefore, the present embodiment is an energy storage device in which a member including a second electrode is sandwiched between folded portions of a member including a first electrode that is folded, and includes a member including the first electrode and a second electrode. It is an object of the present invention to provide a power storage element that is not easily displaced from a member including an electrode.

本実施形態の蓄電素子は、
第一の電極を含むと共に、第一方向における一方側を開放するようにターン部で折り返された第一折り返し部、及び、前記第一方向における他方側を開放するようにターン部で折り返された第二折り返し部が交互に配されるようつづら折りされた長尺の第一部材と、
前記第一の電極と極性の異なる第二の電極を含み且つ前記第一折り返し部の内側に配置された第一の第二部材、及び、前記第二の電極を含み且つ前記第二折り返し部の内側に配置された第二の第二部材を含む複数の第二部材と、
を有する電極体
を備え、
前記第一の第二部材の前記他方側の端部は、前記第一折り返し部の前記ターン部に当接し、
前記第二の第二部材の前記一方側の端部は、前記第二折り返し部の前記ターン部に当接する。 The electricity storage device of this embodiment is
The first folded portion including the first electrode and folded at the turn portion so as to open one side in the first direction, and folded at the turn portion so as to open the other side in the first direction A long first member that is spelled so that the second folded portions are alternately arranged;
A first second member including a second electrode having a polarity different from that of the first electrode and disposed inside the first folded portion; and a second second member including the second electrode and the second folded portion. A plurality of second members including a second second member disposed inside;
An electrode body having
The other end portion of the first second member abuts on the turn portion of the first folded portion,
The one end portion of the second second member is in contact with the turn portion of the second folded portion.

かかる構成によれば、第二部材の端部が第一折り返し部又は第二折り返し部のターン部に当接しているため、第二部材がターン部側に移動することを抑制できる。換言すると、第二部材が第一折り返し部又は第二折り返し部のターン部により位置決めされるため、第一部材と第二部材とが位置ずれしにくい。   According to this structure, since the edge part of the 2nd member is contact | abutting to the turn part of the 1st return part or the 2nd return part, it can suppress that a 2nd member moves to the turn part side. In other words, since the second member is positioned by the first folded portion or the turn portion of the second folded portion, the first member and the second member are not easily displaced.

前記第二の電極は、本体部と、該本体部から前記第一方向及び前記複数の第二部材が並ぶ方向のいずれにも直交する第二方向に突出するタブ部とを含み、
前記第一方向において、
前記第一の第二部材における前記他方側の端縁から前記タブ部の中心までの距離をＬ１とし、前記第二の第二部材における前記一方側の端縁から前記タブ部の中心までの距離をＬ２とし、前記第一折り返し部の前記ターン部の谷折り面から前記第二折り返し部の前記ターン部の谷折り面までの距離をＬ３とし、前記タブ部の幅をＴ１としたとき、以下の数式を満たしてもよい。
Ｌ３＞Ｔ１
Ｌ３−Ｔ１＜Ｌ１＋Ｌ２＜Ｌ３＋Ｔ１ The second electrode includes a main body part and a tab part protruding from the main body part in a second direction orthogonal to both the first direction and the direction in which the plurality of second members are arranged,
In the first direction,
The distance from the other end edge of the first second member to the center of the tab portion is L1, and the distance from the one end edge of the second second member to the center of the tab portion is L1. Is L2, the distance from the valley fold surface of the turn portion of the first folded portion to the valley fold surface of the turn portion of the second folded portion is L3, and the width of the tab portion is T1, May be satisfied.
L3> T1
L3-T1 <L1 + L2 <L3 + T1

第二部材の端部が第一折り返し部又は第二折り返し部のターン部に当接している構成では、第一部材のターン部の位置によって第二部材の端部の位置が定まることになる。このため、複数の第二部材の並ぶ方向から見て、第一の第二部材の端部と第二の第二部材の端部とは、必ずしも一致しない。その結果、複数の第二部材が並ぶ方向から見て、第一の第二部材におけるタブ部と第二の第二部材におけるタブ部とが重ならない場合があるという新たな課題が生じる。一方、かかる構成によれば、第一の第二部材の他方側の端縁（第一折り返し部のターン部に当接させる端縁）を基準とした距離や、第二の第二部材の一方側の端縁（第二折り返し部のターン部に当接させる端縁）を基準とした距離に応じてタブ部の位置を定めているため、第一、第二の第二部材の第一方向における端部の位置にかかわらず、第一、第二の第二部材でタブ部の少なくとも一部を重ねることができる。   In the configuration in which the end portion of the second member is in contact with the first folded portion or the turn portion of the second folded portion, the position of the end portion of the second member is determined by the position of the turn portion of the first member. For this reason, when viewed from the direction in which the plurality of second members are arranged, the end portion of the first second member does not necessarily match the end portion of the second second member. As a result, there is a new problem that the tab portion of the first second member and the tab portion of the second second member may not overlap each other when viewed from the direction in which the plurality of second members are arranged. On the other hand, according to this structure, the distance on the basis of the other side edge of the first second member (the edge to be in contact with the turn portion of the first folded portion) or one of the second second members Since the position of the tab portion is determined according to the distance based on the side edge (the edge to be brought into contact with the turn portion of the second folded portion), the first direction of the first and second second members Regardless of the position of the end portion, the tab portion can be overlapped with the first and second second members.

前記蓄電素子では、
前記第二の電極は、板状の本体部と、該本体部から前記第一方向及び前記複数の第二部材が並ぶ方向のいずれにも直交する第二方向に突出するタブ部とを含み、
前記複数の第二部材の各々は、前記本体部を挟むセパレータを有し、
前記第一の第二部材の形状と前記第二の第二部材の形状とは同じであり、
前記第一方向において、
前記第一部材における前記第一折り返し部の前記ターン部の谷折り面と前記第一部材における前記第二折り返し部の前記ターン部の谷折り面との間の距離をＸとし、前記セパレータの長さをＹとし、前記タブ部の幅をＴ１としたとき、以下の数式を満たしてもよい。
２Ｘ＞Ｔ１
Ｘ−（Ｔ１／２）＜Ｙ＜Ｘ＋（Ｔ１／２） In the storage element,
The second electrode includes a plate-like main body portion, and a tab portion protruding from the main body portion in a second direction orthogonal to both the first direction and the direction in which the plurality of second members are arranged,
Each of the plurality of second members has a separator sandwiching the main body portion,
The shape of the first second member and the shape of the second second member are the same,
In the first direction,
The distance between the valley fold surface of the turn portion of the first folded portion of the first member and the valley fold surface of the turn portion of the second folded portion of the first member is X, and the length of the separator When the thickness is Y and the width of the tab portion is T1, the following formula may be satisfied.
2X> T1
X- (T1 / 2) <Y <X + (T1 / 2)

第二部材の端部が第一折り返し部又は第二折り返し部のターン部に当接している構成では、第一部材のターン部の位置によって第二部材の端部の位置が定まることになる。このため、複数の第二部材の並ぶ方向から見て、第一の第二部材の端部と第二の第二部材の端部とは、必ずしも一致しない。その結果、複数の第二部材が並ぶ方向から見て、第一の第二部材におけるタブ部と第二の第二部材におけるタブ部とが重ならない場合があるという新たな課題が生じる。一方、かかる構成によれば、セパレータの第一方向における長さを、第一折り返し部及び第二折り返し部のターン部の谷折り面同士の距離に応じて調整することで、異なる形状の第二部材を用いることなく、第一、第二の第二部材でタブ部を重ねることができる。   In the configuration in which the end portion of the second member is in contact with the first folded portion or the turn portion of the second folded portion, the position of the end portion of the second member is determined by the position of the turn portion of the first member. For this reason, when viewed from the direction in which the plurality of second members are arranged, the end portion of the first second member does not necessarily match the end portion of the second second member. As a result, there is a new problem that the tab portion of the first second member and the tab portion of the second second member may not overlap each other when viewed from the direction in which the plurality of second members are arranged. On the other hand, according to such a configuration, the length in the first direction of the separator is adjusted according to the distance between the valley fold surfaces of the turn portions of the first folded portion and the second folded portion, thereby allowing the second shapes having different shapes. A tab part can be piled up by the 1st and 2nd 2nd member, without using a member.

前記蓄電素子は、
前記電極体を含むケース、を備え、
前記複数の第二部材の各々は、折り曲げ部を含むセパレータであって、前記第二の電極を挟むセパレータと、該セパレータから前記第一方向及び前記複数の第二部材が並ぶ方向のいずれにも直交する第二方向に突出するタブ部であって前記第二の電極の一部であるタブ部とを含み、
前記第二方向において、
前記第一の第二部材の前記セパレータにおける前記タブ部が突出する側と反対側の端部から前記タブ部が突出する位置までの寸法は、前記第二の第二部材の前記セパレータにおける前記タブ部が突出する側と反対側の端部から前記タブ部が突出する位置までの寸法と同じであり、
前記第一の第二部材の前記タブ部の突出量は、前記第二の第二部材の前記タブ部の突出量と同じであり、
前記折り曲げ部の谷折り面は、前記第二の電極の前記本体部における前記タブ部が突出する側と反対の端部を覆い、
前記電極体は、前記セパレータの前記折り曲げ部の山折り面を前記ケースの内面に直接または間接に当接させた状態で、前記ケース内に配置されていてもよい。 The power storage element is
A case including the electrode body,
Each of the plurality of second members is a separator including a bent portion, and both the separator sandwiching the second electrode and the first direction and the direction in which the plurality of second members are arranged from the separator. A tab portion protruding in a second direction orthogonal to each other, and a tab portion that is a part of the second electrode,
In the second direction,
The dimension from the end of the first second member opposite to the side where the tab portion protrudes to the position where the tab portion protrudes is the tab of the separator of the second second member. It is the same as the dimension from the end opposite to the side from which the part protrudes to the position where the tab part protrudes,
The protruding amount of the tab portion of the first second member is the same as the protruding amount of the tab portion of the second second member,
The valley fold surface of the bent portion covers the end opposite to the side from which the tab portion protrudes in the main body portion of the second electrode,
The electrode body may be disposed in the case in a state where a mountain fold surface of the bent portion of the separator is in direct or indirect contact with an inner surface of the case.

かかる構成によれば、セパレータのタブ部が突出する側と反対側の端部がケースの内部に当接しているため、第二の電極のタブ部の第二方向における位置を揃えることができる。   According to this configuration, since the end of the separator opposite to the side from which the tab portion projects is in contact with the inside of the case, the tab portion of the second electrode can be aligned in the second direction.

前記蓄電素子では、
前記複数の第二部材の各々は、折り曲げ部を含むセパレータであって、前記第二の電極を挟むセパレータを有し、
前記第一の第二部材において、
前記第二の電極の前記他方側の端部は、前記セパレータの前記折り曲げ部の谷折り面に当接し、
前記セパレータの前記折り曲げ部の山折り面は、前記第一折り返し部の前記ターン部に当接し、
前記第二の第二部材において、
前記第二の電極の前記一方側の端部は、前記セパレータの前記折り曲げ部の谷折り面に当接し、
前記セパレータの前記折り曲げ部の山折り面は、前記第二折り返し部の前記ターン部に当接してもよい。 In the storage element,
Each of the plurality of second members is a separator including a bent portion, and has a separator sandwiching the second electrode,
In the first second member,
The other end of the second electrode is in contact with the valley fold surface of the bent portion of the separator,
The mountain fold surface of the bent portion of the separator abuts on the turn portion of the first folded portion,
In the second second member,
The one end of the second electrode is in contact with the valley fold surface of the bent portion of the separator,
The mountain fold surface of the bent portion of the separator may contact the turn portion of the second folded portion.

かかる構成によれば、谷折り面側に第二の電極の端部が当接されたセパレータの折り曲げ部の山折り面が、第一折り返し部又は第二折り返し部のターン部に当接するため、セパレータが第一部材のターン部側に位置ずれしにくく、第二の電極がセパレータの折り曲げ部側に位置ずれしにくい。その結果、第二の電極が第一部材のターン部側に位置ずれしにくい。   According to such a configuration, because the mountain fold surface of the folded portion of the separator with which the end portion of the second electrode is in contact with the valley fold surface side is in contact with the turn portion of the first folded portion or the second folded portion, The separator is unlikely to be displaced toward the turn part side of the first member, and the second electrode is not likely to be displaced toward the bent part side of the separator. As a result, the second electrode is unlikely to be displaced toward the turn part side of the first member.

前記蓄電素子では、
前記第二の電極は、本体部と、該本体部から前記第一方向及び前記複数の第二部材が並ぶ方向のいずれにも直交する第二方向に突出するタブ部とを含み
前記第一方向において、
前記第一の第二部材における第二の電極と前記第二の第二部材における第二の電極とで、前記他方側の端縁同士の位置が異なり、
前記第二の第二部材における前記第二の電極の形状は、前記第一の第二部材における前記第二の電極を反転させた形状と同一であり、
前記第一の第二部材において、
前記タブ部は、前記第一の第二部材における前記第二の電極の前記他方側の端縁と前記第一の第二部材における前記第二の電極の前記一方側の端縁との中心から、前記一方側にずれており、
前記タブ部のずれ量をＡとし、前記第一の第二部材における前記第二の電極の前記他方側の端縁と前記第二の第二部材における前記第二の電極の前記他方側の端縁との距離をＢとし、前記タブ部の幅をＴ１としたとき、以下の数式を満たしてもよい。
Ｂ＞Ｔ１
（Ｂ／２）−（Ｔ１／２）＜Ａ＜（Ｂ／２）＋（Ｔ１／２） In the storage element,
The second electrode includes a main body portion and a tab portion protruding from the main body portion in a second direction orthogonal to both the first direction and the direction in which the plurality of second members are arranged. In
In the second electrode in the first second member and the second electrode in the second second member, the positions of the edges on the other side are different,
The shape of the second electrode in the second second member is the same as the inverted shape of the second electrode in the first second member,
In the first second member,
The tab portion is formed from the center of the other end edge of the second electrode in the first second member and the one end edge of the second electrode in the first second member. , Shifted to the one side,
The deviation amount of the tab portion is A, and the other end of the second electrode in the first second member and the other end of the second electrode in the second second member. When the distance from the edge is B and the width of the tab portion is T1, the following formula may be satisfied.
B> T1
(B / 2)-(T1 / 2) <A <(B / 2) + (T1 / 2)

かかる構成によれば、第一、第二の第二部材で異なる形状の第二の電極を用いることなく、第一、第二の第二部材における第二の電極でタブ部同士の位置を重ねることができる。   According to such a configuration, the positions of the tab portions are overlapped by the second electrode in the first and second second members without using the second electrodes having different shapes in the first and second second members. be able to.

本実施形態の蓄電素子によれば、つづら折りされた第一の電極を含む部材の折り返し部に第二の電極を含む部材が狭持された蓄電素子であって、第一の電極を含む部材と第二の電極を含む部材とが位置ずれしにくい蓄電素子を提供することができる。   According to the electricity storage device of the present embodiment, the electricity storage device in which the member including the second electrode is sandwiched between the folded portions of the member including the first electrode folded in a zigzag manner, and the member including the first electrode; It is possible to provide a power storage element that is less likely to be displaced from the member including the second electrode.

図１は、本発明の一実施形態に係る蓄電素子の斜視図である。FIG. 1 is a perspective view of a power storage device according to an embodiment of the present invention. 図２は、前記蓄電素子の分解斜視図である。FIG. 2 is an exploded perspective view of the power storage element. 図３は、図１のＩＩＩ―ＩＩＩ線位置の断面図である。3 is a cross-sectional view taken along the line III-III in FIG. 図４は、電極体の構成を説明するための斜視図である。FIG. 4 is a perspective view for explaining the configuration of the electrode body. 図５は、第一部材と第二部材との位置関係を説明するための断面模式図である。FIG. 5 is a schematic cross-sectional view for explaining the positional relationship between the first member and the second member. 図６は、負極の構成を説明するための図である。FIG. 6 is a diagram for explaining the configuration of the negative electrode. 図７は、つづら折り状態の負極の構成を説明するための斜視図である。FIG. 7 is a perspective view for explaining the structure of the negatively folded negative electrode. 図８は、負極の折り返し部を説明するための斜視図である。FIG. 8 is a perspective view for explaining a folded portion of the negative electrode. 図９は、第二部材の構成を説明するための図である。FIG. 9 is a diagram for explaining the configuration of the second member. 図１０は、第二部材の構成を説明するための図である。FIG. 10 is a diagram for explaining the configuration of the second member. 図１１は、折り返し部を説明するための断面模式図である。FIG. 11 is a schematic cross-sectional view for explaining the folded portion. 図１２は、折り返し部及び正極タブを説明するための模式図である。FIG. 12 is a schematic diagram for explaining the folded portion and the positive electrode tab. 図１３は、他実施形態に係る折り返し部及び正極タブを説明するための模式図である。FIG. 13 is a schematic diagram for explaining a folded portion and a positive electrode tab according to another embodiment. 図１４は、他実施形態に係る折り返し部及び正極タブを説明するための模式図である。FIG. 14 is a schematic diagram for explaining a folded portion and a positive electrode tab according to another embodiment. 図１５は、他実施形態に係る第二部材の構成を説明するための斜視図である。FIG. 15 is a perspective view for explaining the configuration of the second member according to another embodiment. 図１６は、他実施形態に係る第二部材の構成を説明するための斜視図である。FIG. 16 is a perspective view for explaining the configuration of the second member according to another embodiment. 図１７は、他実施形態に係る折り返し部及び正極タブを説明するための模式図である。FIG. 17 is a schematic diagram for explaining a folded portion and a positive electrode tab according to another embodiment. 図１８は、前記蓄電素子を備えた蓄電装置の斜視図である。FIG. 18 is a perspective view of a power storage device including the power storage element. 図１９は、従来の蓄電素子の断面図である。FIG. 19 is a cross-sectional view of a conventional power storage element.

以下、本発明に係る蓄電素子の一実施形態について、図１〜図１２を参照しつつ説明する。蓄電素子には、一次電池、二次電池、キャパシタ等がある。本実施形態では、蓄電素子の一例として、充放電可能な二次電池について説明する。尚、本実施形態の各構成部材（各構成要素）の名称は、本実施形態におけるものであり、背景技術における各構成部材（各構成要素）の名称と異なる場合がある。   Hereinafter, an embodiment of a power storage device according to the present invention will be described with reference to FIGS. Examples of the power storage element include a primary battery, a secondary battery, and a capacitor. In the present embodiment, a chargeable / dischargeable secondary battery will be described as an example of a power storage element. In addition, the name of each component (each component) of this embodiment is a thing in this embodiment, and may differ from the name of each component (each component) in background art.

本実施形態の蓄電素子は、非水電解質二次電池である。より詳しくは、蓄電素子は、リチウムイオンの移動に伴って生じる電子移動を利用したリチウムイオン二次電池である。この種の蓄電素子は、電気エネルギーを供給する。蓄電素子は、単一又は複数で使用される。具体的に、蓄電素子は、要求される出力及び要求される電圧が小さいときには、単一で使用される。一方、蓄電素子は、要求される出力及び要求される電圧の少なくとも一方が大きいときには、他の蓄電素子と組み合わされて蓄電装置に用いられる。前記蓄電装置では、該蓄電装置に用いられる蓄電素子が電気エネルギーを供給する。   The electricity storage device of this embodiment is a nonaqueous electrolyte secondary battery. More specifically, the power storage element is a lithium ion secondary battery that utilizes electron transfer that occurs as lithium ions move. This type of power storage element supplies electrical energy. One or a plurality of power storage elements are used. Specifically, the storage element is used singly when the required output and the required voltage are small. On the other hand, when at least one of a required output and a required voltage is large, the power storage element is used in a power storage device in combination with another power storage element. In the power storage device, a power storage element used in the power storage device supplies electric energy.

蓄電素子は、図１〜図３に示すように、電極体２を備える。また、蓄電素子１は、電解液、電極体２と電解液とを収容するケース３、電極体２とケース３との間に配置される絶縁部材４、及び、少なくとも一部が外部に露出する外部端子５等も備える。尚、各図においては、構造を示すために、電極体２を構成する電極等の厚さを誇張して表す等、電極体２の構成を模式的に表している。   The power storage element includes an electrode body 2 as shown in FIGS. In addition, the storage element 1 has an electrolytic solution, a case 3 containing the electrode body 2 and the electrolytic solution, an insulating member 4 disposed between the electrode body 2 and the case 3, and at least a part thereof exposed to the outside. An external terminal 5 is also provided. In each figure, in order to show the structure, the configuration of the electrode body 2 is schematically shown, such as exaggerating the thickness of the electrodes that constitute the electrode body 2.

電解液は、非水溶液系電解液である。この電解液は、有機溶媒に電解質塩を溶解させることによって得られる。有機溶媒は、例えば、プロピレンカーボネート及びエチレンカーボネートなどの環状炭酸エステル類、ジメチルカーボネート、ジエチルカーボネート、及びエチルメチルカーボネートなどの鎖状カーボネート類である。電解質塩は、ＬｉＣｌＯ４、ＬｉＢＦ４、及びＬｉＰＦ６等である。本実施形態の電解液は、エチレンカーボネート、ジメチルカーボネート、及びエチルメチルカーボネートを、エチレンカーボネート：ジメチルカーボネート：エチルメチルカーボネート＝３：２：５の割合で調整した混合溶媒に、１ｍｏｌ／ＬのＬｉＰＦ６を溶解させたものである。 The electrolytic solution is a non-aqueous electrolytic solution. This electrolytic solution is obtained by dissolving an electrolyte salt in an organic solvent. Examples of the organic solvent include cyclic carbonates such as propylene carbonate and ethylene carbonate, and chain carbonates such as dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate. The electrolyte salt is LiClO 4 , LiBF 4 , LiPF 6 or the like. The electrolytic solution of the present embodiment was prepared by adding 1 mol / L LiPF 6 to a mixed solvent prepared by adjusting ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate at a ratio of ethylene carbonate: dimethyl carbonate: ethyl methyl carbonate = 3: 2: 5. Is dissolved.

電極体２は、図４及び図５にも示すように、第一部材２１と、第二部材２２と、を有する。第一部材２１は、第一の電極２１０を含む。第二部材２２は、第一の電極２１０と極性の異なる第二の電極２２０を含む。   As shown in FIGS. 4 and 5, the electrode body 2 includes a first member 21 and a second member 22. The first member 21 includes a first electrode 210. The second member 22 includes a second electrode 220 having a polarity different from that of the first electrode 210.

本実施形態の電極体２は、第一の電極２１０と第二の電極２２０との間に配置されるセパレータ２２１も有する。また、本実施形態の電極体２では、第二部材２２は、第二の電極２２０に加えて、セパレータ２２１も含む。さらに、本実施形態の電極体２では、第一部材２１は、第一の電極２１０で構成される。尚、本実施形態の電極体２では、第一の電極２１０は、負極であり、第二の電極２２０は、正極である。   The electrode body 2 of this embodiment also includes a separator 221 that is disposed between the first electrode 210 and the second electrode 220. In the electrode body 2 of the present embodiment, the second member 22 includes a separator 221 in addition to the second electrode 220. Furthermore, in the electrode body 2 of the present embodiment, the first member 21 is configured by the first electrode 210. In the electrode body 2 of the present embodiment, the first electrode 210 is a negative electrode, and the second electrode 220 is a positive electrode.

負極２１０は、図６及び図７にも示すように、金属箔２１１と、金属箔２１１の両面のそれぞれに重ねられる負極活物質層２１２と、を有する。即ち、負極２１０は、一つの金属箔２１１と、一対の負極活物質層２１２と、を有する。本実施形態の金属箔２１１は、例えば、銅箔である。   As shown in FIGS. 6 and 7, the negative electrode 210 includes a metal foil 211 and a negative electrode active material layer 212 stacked on both surfaces of the metal foil 211. That is, the negative electrode 210 includes one metal foil 211 and a pair of negative electrode active material layers 212. The metal foil 211 of this embodiment is a copper foil, for example.

この負極２１０は、長尺な帯状であり、複数の折り返し部２３を有するようにつづら折りされている。具体的に、負極２１０は、第一方向（長尺方向）における一方側を開放するようにターン部２３４で折り返された第一折り返し部２３Ａ、及び、長尺方向における他方側を開放するようにターン部２３４で折り返された第二折り返し部２３Ｂが交互に配されるよう、つづら折りされている（図７参照）。   The negative electrode 210 has a long band shape and is folded so as to have a plurality of folded portions 23. Specifically, the negative electrode 210 opens the first folded portion 23A folded by the turn portion 234 so as to open one side in the first direction (long direction) and the other side in the long direction. The second folded portions 23B folded at the turn portions 234 are folded in a zigzag manner (see FIG. 7).

負極活物質層２１２は、負極活物質と、バインダーと、を有する。   The negative electrode active material layer 212 includes a negative electrode active material and a binder.

負極活物質は、例えば、グラファイト、難黒鉛化炭素、及び易黒鉛化炭素などの炭素材、又は、ケイ素（Ｓｉ）及び錫（Ｓｎ）などのリチウムイオンと合金化反応を生じる材料である。本実施形態の負極活物質は、グラファイトである。   The negative electrode active material is, for example, a carbon material such as graphite, non-graphitizable carbon, and graphitizable carbon, or a material that causes an alloying reaction with lithium ions such as silicon (Si) and tin (Sn). The negative electrode active material of this embodiment is graphite.

負極活物質層２１２に用いられるバインダーは、例えば、ポリフッ化ビニリデン（ＰＶｄＦ）、エチレンとビニルアルコールとの共重合体、ポリメタクリル酸メチル、ポリエチレンオキサイド、ポリプロピレンオキサイド、ポリビニルアルコール、ポリアクリル酸、ポリメタクリル酸、スチレンブタジエンゴム（ＳＢＲ）である。本実施形態のバインダーは、ポリフッ化ビニリデンである。   Examples of the binder used for the negative electrode active material layer 212 include polyvinylidene fluoride (PVdF), a copolymer of ethylene and vinyl alcohol, polymethyl methacrylate, polyethylene oxide, polypropylene oxide, polyvinyl alcohol, polyacrylic acid, and polymethacrylic acid. Acid, styrene butadiene rubber (SBR). The binder of this embodiment is polyvinylidene fluoride.

負極活物質層２１２は、ケッチェンブラック（登録商標）、アセチレンブラック、黒鉛等の導電助剤をさらに有してもよい。本実施形態の負極活物質層２１２は、導電助剤を有していない。   The negative electrode active material layer 212 may further include a conductive additive such as ketjen black (registered trademark), acetylene black, or graphite. The negative electrode active material layer 212 of this embodiment does not have a conductive additive.

第一折り返し部２３Ａは、内側の面である谷折り面２３１及び外側の面（谷折り面２３１と反対側の面）である山折り面２３２をそれぞれ有し且つ谷折り面２３１同士を対向させた一対の平坦部２３３と、一対の平坦部２３３の端部同士を接続するターン部２３４と、を含む。第二折り返し部２３Ｂも、第一折り返し部２３Ａと同様の構成を有する。   The first folded portion 23A has a valley fold surface 231 that is an inner surface and a mountain fold surface 232 that is an outer surface (surface opposite to the valley fold surface 231), and makes the valley fold surfaces 231 face each other. A pair of flat portions 233 and a turn portion 234 connecting the ends of the pair of flat portions 233 are included. The second folded portion 23B has the same configuration as the first folded portion 23A.

ターン部２３４は、図１１にも示すように、負極２１０における平坦部２３３を除いた領域（図１１における境界αよりも外側の部分）である。本実施形態のターン部２３４では、山折り面（外周面）及び谷折り面（内周面）はいずれも、Ｘ軸方向における中央に位置する平坦な部分と、この平坦な部分の両側に位置し湾曲した部分とを有する。   As shown in FIG. 11, the turn portion 234 is a region (a portion outside the boundary α in FIG. 11) excluding the flat portion 233 in the negative electrode 210. In the turn part 234 of the present embodiment, both the mountain fold surface (outer peripheral surface) and the valley fold surface (inner peripheral surface) are positioned at a flat portion located at the center in the X-axis direction and on both sides of the flat portion. And a curved portion.

本実施形態の負極２１０は、ターン部２３４を反対に向けた状態で隣り合う第一折り返し部２３Ａ及び第二折り返し部２３Ｂ同士がその一部（平坦部２３３）を共通させた状態で連続するつづら折り状態（蛇腹状）である。即ち、図７において、第一折り返し部２３Ａに着目したときに、第一折り返し部２３Ａと、その隣（図７における下側）の第二折り返し部２３Ｂとでは、第一折り返し部２３Ａのターン部２３４と、第二折り返し部２３Ｂのターン部２３４との間の平坦部２３３Ａ、２３３Ｂを共通させている。   In the negative electrode 210 of the present embodiment, the first folded portion 23A and the second folded portion 23B that are adjacent to each other with the turn portion 234 facing away from each other are continuously folded in a state in which a part (flat portion 233) is shared. It is in a state (bellows shape). That is, in FIG. 7, when paying attention to the first folded portion 23A, the first folded portion 23A and the second folded portion 23B adjacent thereto (the lower side in FIG. 7) have a turn portion of the first folded portion 23A. The flat portions 233A and 233B between the H.234 and the turn portion 234 of the second folded portion 23B are made common.

具体的には、負極２１０では、帯状の負極２１０が長尺方向において所定間隔で交互に折り返されることによって、平坦部２３３とターン部２３４とが交互に形成されている。即ち、長尺な負極２１０が、図６に示す長手方向に所定間隔で交互に設定された山折り線２１Ａの位置と谷折り線２１Ｂの位置とで山折り及び谷折りが交互に繰り返されることによって、つづら折り状態となる。これにより、負極２１０は、複数の平坦部２３３と複数のターン部２３４とを有し、複数の平坦部２３３のそれぞれは、平行若しくは略平行に並び、複数のターン部２３４のそれぞれは、隣り合う平坦部２３３の長尺方向の一端側の端部同士と他端側の端部同士とを交互に接続している。   Specifically, in the negative electrode 210, the flat portions 233 and the turn portions 234 are alternately formed by alternately folding the strip-shaped negative electrodes 210 at predetermined intervals in the longitudinal direction. That is, in the long negative electrode 210, mountain folds and valley folds are alternately repeated at the positions of the mountain fold lines 21A and the valley fold lines 21B alternately set at predetermined intervals in the longitudinal direction shown in FIG. As a result, the spelling is folded. Accordingly, the negative electrode 210 includes a plurality of flat portions 233 and a plurality of turn portions 234, each of the plurality of flat portions 233 being arranged in parallel or substantially in parallel, and each of the plurality of turn portions 234 being adjacent to each other. The ends on the one end side in the longitudinal direction of the flat portion 233 and the ends on the other end side are alternately connected.

以下では、第二部材２２が並ぶ方向を直交座標系におけるＸ軸方向とし、平坦部２３３に対してターン部２３４が配置されている方向（図５における左右方向）を直交座標系におけるＹ軸方向（第一方向）とし、Ｙ軸方向及び複数の第二部材２２が並ぶ方向のいずれにも直交する方向（負極２１０の折目（山折り線２１Ａ、谷折り線２１Ｂ）方向）を直交座標系のＺ軸方向（第二方向）とする。   Hereinafter, the direction in which the second members 22 are arranged is defined as the X-axis direction in the orthogonal coordinate system, and the direction in which the turn portion 234 is disposed with respect to the flat portion 233 (the left-right direction in FIG. 5) is the Y-axis direction in the orthogonal coordinate system. (First direction) and a direction orthogonal to both the Y-axis direction and the direction in which the plurality of second members 22 are arranged (the direction of the fold line (mountain fold line 21A, valley fold line 21B) of the negative electrode 210) is an orthogonal coordinate system. The Z-axis direction (second direction).

複数の平坦部２３３のそれぞれは、図７及び図８に示すように、矩形状の平坦部本体２３３１と、平坦部本体２３３１の矩形状の輪郭を構成する一辺から突出する（本実施形態の例では、Ｚ軸方向の端縁からＺ軸方向に延びる負極タブ２３３２と、を有する。本実施形態の平坦部本体２３３１は、Ｙ軸方向に長い矩形状である。平坦部本体２３３１では、金属箔２１１の両面が負極活物質層２１２に覆われ、負極タブ２３３２では、金属箔２１１が露出している。即ち、負極タブ２３３２は、負極活物質層２１２を有しない。   As shown in FIGS. 7 and 8, each of the plurality of flat portions 233 protrudes from a rectangular flat portion main body 2331 and from one side constituting the rectangular outline of the flat portion main body 2331 (example of this embodiment) Then, it has a negative electrode tab 2332 extending in the Z-axis direction from the edge in the Z-axis direction, The flat portion main body 2331 of this embodiment has a rectangular shape that is long in the Y-axis direction. Both surfaces of 211 are covered with the negative electrode active material layer 212, and the metal foil 211 is exposed in the negative electrode tab 2332. That is, the negative electrode tab 2332 does not have the negative electrode active material layer 212.

つづら折り状態の負極２１０において、各平坦部２３３の負極タブ２３３２は、Ｘ軸方向から見て重なっている。本実施形態の負極２１０では、各負極タブ２３３２は、平坦部本体２３３１のＺ軸方向の一方（図７における上側）の端縁におけるＹ軸方向の他方側（図７における右側）の端部からＺ軸方向に延びている。この複数の平坦部本体２３３１のそれぞれから延びている負極タブ２３３２は、束ねられ、集電体６を介して外部端子５と接続されている（図３参照）。本実施形態の負極タブ２３３２の束は、集電体６に溶接されている。   In the zigzag folded negative electrode 210, the negative electrode tabs 2332 of the flat portions 233 overlap each other when viewed from the X-axis direction. In the negative electrode 210 of the present embodiment, each negative electrode tab 2332 is formed from the end on the other side (right side in FIG. 7) in the Y-axis direction at one end (upper side in FIG. 7) of the flat portion main body 2331 in the Z-axis direction. It extends in the Z-axis direction. The negative electrode tabs 2332 extending from each of the plurality of flat portion main bodies 2331 are bundled and connected to the external terminal 5 via the current collector 6 (see FIG. 3). The bundle of negative electrode tabs 2332 of this embodiment is welded to the current collector 6.

複数のターン部２３４のそれぞれは、つづら折り状態の負極２１０において、Ｚ軸方向に延びる軸を折り返し軸２３４Ｓ（図７参照）として帯状の負極２１０が旋回している（換言すると、折り返し軸２３４Ｓに沿った折目が形成されるように折り返されている）部位である。このターン部２３４においても、金属箔２１１の両面が負極活物質層２１２に覆われている。   In each of the plurality of turn portions 234, the belt-shaped negative electrode 210 is swung around the negative electrode 210 in a zigzag state with the axis extending in the Z-axis direction as a return shaft 234S (see FIG. 7) (in other words, along the return shaft 234S). (Folded so that a fold is formed). Also in this turn part 234, both surfaces of the metal foil 211 are covered with the negative electrode active material layer 212.

第二部材２２は、図１１に示すように、第一折り返し部２３Ａに挟まれている第一の第二部材２２Ａと、第二折り返し部２３Ｂに挟まれている第二の第二部材２２Ｂとを含む。本実施形態の第二部材２２において、第一の第二部材２２Ａに含まれる正極２２０と、第二の第二部材２２Ｂに含まれる正極２２０とは、その形状を除く点では共通している。   As shown in FIG. 11, the second member 22 includes a first second member 22A sandwiched between the first folded portions 23A, and a second second member 22B sandwiched between the second folded portions 23B. including. In the second member 22 of the present embodiment, the positive electrode 220 included in the first second member 22A and the positive electrode 220 included in the second second member 22B are common except for the shape thereof.

正極２２０は、図９及び図１０にも示すように、金属箔２２２と、金属箔２２２の両面のそれぞれに重ねられる正極活物質層２２３と、を有する。即ち、正極２２０は、一つの金属箔２２２と一対の正極活物質層２２３とを有する。本実施形態の金属箔２２２は、例えば、アルミニウム箔である。この正極２２０は、セパレータ２２１に覆われた状態で、つづら折り状態の負極２１０において、Ｘ軸方向に隣り合う平坦部２３３間のそれぞれに配置されている。具体的には、正極２２０は、セパレータ２２１に覆われた状態で、第一折り返し部２３Ａ又は第二折り返し部２３Ｂに挟まれている。このため、本実施形態の電極体２は、複数の正極２２０を有している。   As shown in FIGS. 9 and 10, the positive electrode 220 includes a metal foil 222 and a positive electrode active material layer 223 that is stacked on both surfaces of the metal foil 222. That is, the positive electrode 220 includes one metal foil 222 and a pair of positive electrode active material layers 223. The metal foil 222 of this embodiment is an aluminum foil, for example. The positive electrode 220 is disposed between the flat portions 233 adjacent to each other in the X-axis direction in the zigzag folded negative electrode 210 while being covered with the separator 221. Specifically, the positive electrode 220 is sandwiched between the first folded portion 23A or the second folded portion 23B while being covered with the separator 221. For this reason, the electrode body 2 of this embodiment has a plurality of positive electrodes 220.

正極活物質層２２３は、正極活物質と、バインダーと、を有する。   The positive electrode active material layer 223 includes a positive electrode active material and a binder.

本実施形態の正極活物質は、例えば、リチウム金属酸化物である。具体的に、正極活物質は、例えば、ＬｉａＭｅｂＯｃ（Ｍｅは、１又は２以上の遷移金属を表す）によって表される複合酸化物（ＬｉａＣｏｙＯ２、ＬｉａＮｉｘＯ２、ＬｉａＭｎｚＯ４、ＬｉａＮｉｘＣｏｙＭｎｚＯ２等）、ＬｉａＭｅｂ（ＸＯｃ）ｄ（Ｍｅは、１又は２以上の遷移金属を表し、Ｘは例えばＰ、Ｓｉ、Ｂ、Ｖを表す）によって表されるポリアニオン化合物（ＬｉａＦｅｂＰＯ４、ＬｉａＭｎｂＰＯ４、ＬｉａＭｎｂＳｉＯ４、ＬｉａＣｏｂＰＯ４Ｆ等）である。本実施形態の正極活物質は、ＬｉＮｉ１／３Ｃｏ１／３Ｍｎ１／３Ｏ２である。 The positive electrode active material of this embodiment is a lithium metal oxide, for example. Specifically, the positive electrode active material is, for example, a composite oxide represented by LiaMebOc (Me represents one or more transition metals) (LiaCoyO 2 , LiaNixO 2 , LiaMnzO 4 , LiaNixCoyMnzO 2 etc.), LiaMeb ( XOc) d (Me represents one or more transition metals, and X represents, for example, P, Si, B, V) (LiaFebPO 4 , LiaMnbPO 4 , LiaMnbSiO 4 , LiaCobPO 4 F, etc.) ). The positive electrode active material of this embodiment is LiNi 1/3 Co 1/3 Mn 1/3 O 2 .

正極活物質層２２３に用いられるバインダーは、負極活物質層２１２に用いられたバインダーと同様のものである。本実施形態のバインダーは、ポリフッ化ビニリデンである。   The binder used for the positive electrode active material layer 223 is the same as the binder used for the negative electrode active material layer 212. The binder of this embodiment is polyvinylidene fluoride.

正極活物質層２２３は、ケッチェンブラック（登録商標）、アセチレンブラック、黒鉛等の導電助剤をさらに有してもよい。本実施形態の正極活物質層２２３は、導電助剤としてアセチレンブラックを有する。   The positive electrode active material layer 223 may further include a conductive additive such as ketjen black (registered trademark), acetylene black, and graphite. The positive electrode active material layer 223 of this embodiment has acetylene black as a conductive additive.

具体的に、複数の正極２２０のそれぞれは、本体部２２４と、本体部２２４の矩形状の輪郭を構成する一辺であるＺ軸方向の端縁からＺ軸方向に延びる（本実施形態の例では、Ｘ軸方向及びＹ軸方向いずれにも直交するＺ軸方向に延びる）正極タブ（タブ部）２２５と、を有する。本実施形態の本体部２２４は、Ｙ軸方向に長い矩形状であり且つ板状である。本体部２２４では、金属箔２２２の両面が正極活物質層２２３に覆われ、正極タブ２２５では、金属箔２２２が露出している。即ち、正極タブ２２５は、正極活物質層２２３を有しない。   Specifically, each of the plurality of positive electrodes 220 extends in the Z-axis direction from the main body portion 224 and an edge in the Z-axis direction, which is one side constituting the rectangular outline of the main body portion 224 (in the example of the present embodiment). And a positive electrode tab (tab portion) 225 extending in the Z-axis direction orthogonal to both the X-axis direction and the Y-axis direction. The main body 224 of this embodiment has a rectangular shape and a plate shape that are long in the Y-axis direction. In the main body 224, both surfaces of the metal foil 222 are covered with the positive electrode active material layer 223, and the metal foil 222 is exposed in the positive electrode tab 225. That is, the positive electrode tab 225 does not have the positive electrode active material layer 223.

本体部２２４における正極活物質層２２３は、Ｘ軸方向に対向する（詳しくは、セパレータ２２１を介して対向する）平坦部２３３の負極活物質層２１２よりＹ−Ｚ面（Ｙ軸とＺ軸とを含む平面）方向において小さい。即ち、本体部２２４の正極活物質層２２３は、全域において平坦部２３３の負極活物質層２１２と対向し、平坦部２３３の負極活物質層２１２は、周縁部を除いた領域において本体部２２４の正極活物質層２２３と対向する。本体部２２４のＺ軸方向における寸法は、負極２１０の平坦部２３３の寸法と比べて、例えば、２ｍｍ〜４ｍｍだけ小さい。   The positive electrode active material layer 223 in the main body portion 224 has a YZ plane (Y-axis and Z-axis) from the negative electrode active material layer 212 of the flat portion 233 facing in the X-axis direction (specifically, facing through the separator 221). Small in the plane) direction. That is, the positive electrode active material layer 223 of the main body portion 224 is opposed to the negative electrode active material layer 212 of the flat portion 233 in the entire region, and the negative electrode active material layer 212 of the flat portion 233 is in the region excluding the peripheral portion. Opposite to the positive electrode active material layer 223. The dimension of the main body part 224 in the Z-axis direction is smaller than the dimension of the flat part 233 of the negative electrode 210 by, for example, 2 mm to 4 mm.

各正極２２０の正極タブ２２５は、Ｘ軸方向から見て重なっている。本実施形態の各正極２２０の正極タブ２２５は、Ｘ軸方向に長い矩形状である（図９、図１０参照）。各正極タブ２２５は、いずれも、同じ形状をしている。また、各正極タブ２２５は、いずれも、本体部２２４のＺ軸方向の一方（図９における上側）の端縁におけるＹ軸方向の一方側（平坦部本体２３３１に対する負極タブ２３３２の位置とは反対側：図９、図１０における左側）の端部からＺ軸方向に延びている。また、各正極タブ２２５のＹ軸方向における両端縁は、いずれも、Ｘ軸方向に延びる。本実施形態のこの複数の本体部２２４のそれぞれから延びている正極タブ２２５は、束ねられ、集電体６を介して外部端子５と接続されている（図３参照）。本実施形態の正極タブ２２５の束は、集電体６に溶接されている。   The positive electrode tab 225 of each positive electrode 220 overlaps when viewed from the X-axis direction. The positive electrode tab 225 of each positive electrode 220 of the present embodiment has a rectangular shape that is long in the X-axis direction (see FIGS. 9 and 10). Each positive electrode tab 225 has the same shape. In addition, each positive electrode tab 225 is opposite to the position of the negative electrode tab 2332 with respect to one side in the Y-axis direction (on the flat portion main body 2331) at one edge in the Z-axis direction (upper side in FIG. 9) of the main body portion 224. Side: It extends in the Z-axis direction from the end of the left side in FIGS. Further, both end edges of each positive electrode tab 225 in the Y-axis direction extend in the X-axis direction. The positive electrode tabs 225 extending from each of the plurality of main body portions 224 of the present embodiment are bundled and connected to the external terminal 5 via the current collector 6 (see FIG. 3). The bundle of positive electrode tabs 225 of this embodiment is welded to the current collector 6.

尚、本実施形態の正極タブ２２５は、本体部２２４のＺ軸方向の一方の端縁における第一の位置、又は、本体部２２４のＺ軸方向の一方の端縁における第二の位置からＺ軸方向に延びている。本体部２２４のＺ軸方向の一方の端縁における一方側の端部から第一の位置までの距離は、本体部２２４のＺ軸方向の一方の端縁における一方側の端部から第二の位置までの距離と異なる。   In addition, the positive electrode tab 225 of this embodiment is Z from the 1st position in one edge of the Z-axis direction of the main-body part 224, or the 2nd position in the one edge of the Z-axis direction of the main-body part 224. It extends in the axial direction. The distance from one end of the one end edge of the main body 224 in the Z-axis direction to the first position is the second distance from the one end of the one end edge of the main body 224 in the Z-axis direction. Different from the distance to the position.

セパレータ２２１は、絶縁性を有する部材であり、負極２１０と正極２２０との間に配置される。これにより、電極体２において、負極２１０と正極２２０とが互いに絶縁される。また、セパレータ２２１は、ケース３内において、電解液を保持する。これにより、蓄電素子１の充放電時において、セパレータ２２１を挟んで対向する負極２１０と正極２２０との間を、リチウムイオンが移動可能となる。   The separator 221 is an insulating member and is disposed between the negative electrode 210 and the positive electrode 220. Thereby, in the electrode body 2, the negative electrode 210 and the positive electrode 220 are insulated from each other. The separator 221 holds the electrolytic solution in the case 3. Thereby, during charging / discharging of the electrical storage element 1, lithium ions can move between the negative electrode 210 and the positive electrode 220 facing each other with the separator 221 interposed therebetween.

このセパレータ２２１は、帯状であり、例えば、ポリエチレン、ポリプロピレン、セルロース、ポリアミドなどの多孔質膜によって構成される。本実施形態のセパレータ２２１は、ＳｉＯ２粒子、Ａｌ２Ｏ３粒子、ベーマイト（アルミナ水和物）等の無機粒子を含んだ無機層を、多孔質膜によって形成された基材の上に設けることで形成されている。本実施形態のセパレータ２２１の基材は、例えば、ポリエチレンによって形成される。 The separator 221 has a strip shape and is made of, for example, a porous film such as polyethylene, polypropylene, cellulose, or polyamide. In the separator 221 of this embodiment, an inorganic layer containing inorganic particles such as SiO 2 particles, Al 2 O 3 particles, boehmite (alumina hydrate) is provided on a substrate formed of a porous film. It is formed with. The base material of the separator 221 of this embodiment is formed of, for example, polyethylene.

本実施形態のセパレータ２２１は、上述のように、正極２２０を覆っている。具体的に、セパレータ２２１は、本体部２２４全体をＸ軸方向に挟み込むように覆っている。この正極２２０を挟み込んだ状態のセパレータ２２１は、Ｘ軸方向から見て矩形状であり、Ｚ軸方向の寸法は、負極２１０の平坦部２３３の寸法より大きく、Ｙ軸方向の寸法は、平坦部２３３の寸法と比べて小さい。尚、この正極２２０を挟み込んだ状態のセパレータ２２１が、第二部材２２である。   The separator 221 of this embodiment covers the positive electrode 220 as described above. Specifically, the separator 221 covers the entire main body 224 so as to be sandwiched in the X-axis direction. The separator 221 sandwiching the positive electrode 220 has a rectangular shape when viewed from the X-axis direction, the dimension in the Z-axis direction is larger than the dimension of the flat portion 233 of the negative electrode 210, and the dimension in the Y-axis direction is a flat portion. It is smaller than the size of 233. The separator 221 in a state where the positive electrode 220 is sandwiched is the second member 22.

また、本実施形態のセパレータ２２１は、折り曲げ部２２１０を有する。具体的に、セパレータ２２１の折り曲げ部２２１０は、矩形状のものを、間に正極２２０を挟み込むようにして長尺方向の中央部で折り曲げられることで形成される。さらに、本実施形態のセパレータ２２１は、折目方向の両端縁（二辺）が接合（接着、溶着等）されている。   Further, the separator 221 of the present embodiment has a bent portion 2210. Specifically, the bent portion 2210 of the separator 221 is formed by bending a rectangular shape at the center in the longitudinal direction with the positive electrode 220 interposed therebetween. Furthermore, the separator 221 of the present embodiment is joined (adhered, welded, etc.) at both edges (two sides) in the fold direction.

本実施形態のセパレータ２２１のうちＹ軸方向における他方側に折り曲げ部２２１０が配されたセパレータ２２１では、セパレータ２２１の折り曲げ部２２１０の谷折り面に、正極２２０のＹ軸方向における他方側の端部２２０Ａが当接している（図９参照）。また、本実施形態のセパレータ２２１のうちＹ軸方向における一方側に折り曲げ部２２１０が配されたセパレータ２２１では、セパレータ２２１の折り曲げ部２２１０の谷折り面に、正極２２０のＹ軸方向における一方側の端部２２０Ｂが当接している（図１０参照）。   In the separator 221 in which the bent portion 2210 is arranged on the other side in the Y-axis direction among the separators 221 of the present embodiment, the end portion on the other side in the Y-axis direction of the positive electrode 220 is formed on the valley fold surface of the bent portion 2210 of the separator 221. 220A is in contact (see FIG. 9). Further, in the separator 221 in which the bent portion 2210 is arranged on one side in the Y-axis direction among the separators 221 of the present embodiment, the valley fold surface of the bent portion 2210 of the separator 221 is on the one side in the Y-axis direction of the positive electrode 220. The end 220B is in contact (see FIG. 10).

尚、本実施形態の折り曲げ部２２１０は、セパレータ２２１における平坦な部分を除いた領域である。また、本実施形態の折り曲げ部２２１０の山折り面は、図１１に示すように、Ｘ軸方向における中央に位置する平坦な部分と、この平坦な部分の両側に位置し湾曲した部分とを有する。折り曲げ部２２１０の谷折り面は、全体的に平坦である。   Note that the bent portion 2210 of this embodiment is a region excluding a flat portion in the separator 221. Further, as shown in FIG. 11, the mountain fold surface of the bent portion 2210 of the present embodiment has a flat portion located at the center in the X-axis direction and curved portions located on both sides of the flat portion. . The valley folding surface of the bent portion 2210 is generally flat.

本実施形態のセパレータ２２１は、図４に示すように、折り曲げ部２２１０に加えて、本体部２２４の表面を覆う第一被覆部２２１１と、本体部２２４の裏面を覆う第二被覆部２２１２と、を含むと共に、第一被覆部２２１１及び第二被覆部２２１２からそれぞれ一方側に延び且つ本体部２２４の一方側の端縁２２４Ｂよりも外側に位置する部位同士を重ねた状態で接合した第一出代部２２１３、又は、第一被覆部２２１１及び前記第二被覆部２２１２からそれぞれ他方側に延び本体部２２４の他方側の端縁２２４Ａよりも外側に位置する部位同士を重ねた状態で接合した第二出代部２２１４も含む。   As shown in FIG. 4, the separator 221 of the present embodiment includes a first covering portion 2211 that covers the surface of the main body portion 224, a second covering portion 2212 that covers the back surface of the main body portion 224, in addition to the bent portion 2210. The first covering portion 2211 and the second covering portion 2212 extending from the first covering portion 2212 to one side and joined to each other in a state where the portions located outside the one end edge 224B of the main body portion 224 are overlapped with each other. The second portion 2213 or the first covering portion 2211 and the second covering portion 2212 extend from the other side to the other side, and are joined in a state where the portions positioned outside the other side edge 224A of the main body portion 224 are overlapped with each other. Also included is a second generation portion 2214.

尚、セパレータ２２１の第一被覆部２２１１及び第二被覆部２２１２は、Ｘ軸方向から見て矩形状であり、このＺ軸方向の寸法は、正極２２０の本体部２２４の寸法と略同じであり、このＹ軸方向の寸法は、正極２２０の本体部２２４の寸法と比べて大きい。   The first covering portion 2211 and the second covering portion 2212 of the separator 221 are rectangular when viewed from the X-axis direction, and the dimensions in the Z-axis direction are substantially the same as the dimensions of the main body portion 224 of the positive electrode 220. The dimension in the Y-axis direction is larger than the dimension of the main body 224 of the positive electrode 220.

また、セパレータ２２１が正極２２０を挟み込んだ状態において、正極タブ２２５が、折り返されたセパレータ２２１から突出し、セパレータ２２１における折目方向の両端縁（二辺）の接合は、正極タブ２２５を避けて行われている。また、第一出代部２２１３のＹ軸方向における寸法及び第二出代部２２１４のＹ軸方向における寸法は、いずれも、セパレータ２２１の厚みよりも大きい（図１１参照）。さらに、正極２２０は金属箔２２２を含み、セパレータ２２１が金属箔２２２のような金属材料を含まないため、正極２２０はセパレータ２２１よりも硬い。尚、本実施形態の電極体２では、セパレータ２２１が正極２２０を挟み込んだ状態で、この両端縁（セパレータ２２１の両端縁）が接合されているため、各第二部材２２は、自身との相対位置を固定した状態で正極２２０を含んでいる。   Further, in a state where the separator 221 sandwiches the positive electrode 220, the positive electrode tab 225 protrudes from the folded separator 221, and joining of both end edges (two sides) in the fold direction of the separator 221 is performed while avoiding the positive electrode tab 225. It has been broken. Moreover, the dimension in the Y-axis direction of the first allowance portion 2213 and the dimension in the Y-axis direction of the second allowance portion 2214 are both larger than the thickness of the separator 221 (see FIG. 11). Further, since the positive electrode 220 includes a metal foil 222 and the separator 221 does not include a metal material such as the metal foil 222, the positive electrode 220 is harder than the separator 221. In the electrode body 2 of the present embodiment, since both end edges (both end edges of the separator 221) are joined with the separator 221 sandwiching the positive electrode 220, each second member 22 is relative to itself. The positive electrode 220 is included with the position fixed.

尚、第一出代部２２１３のＹ軸方向における寸法は、第一出代部２２１３におけるＹ軸方向における両端縁間の距離である。第二出代部２２１４のＹ軸方向における寸法も、同様である。   In addition, the dimension in the Y-axis direction of the first allowance portion 2213 is a distance between both end edges in the Y-axis direction of the first allowance portion 2213. The same applies to the dimensions of the second allowance portion 2214 in the Y-axis direction.

本実施形態の電極体２では、Ｙ軸方向において、第一の第二部材２２Ａの他方側の端部２２Ｃが、第一折り返し部２３Ａのターン部２３４に当接している。具体的には、Ｙ軸方向において、セパレータ２２１の谷折り面に正極２２０の他方側の端部２２０Ａが当接された折り曲げ部２２１０の山折り面は、第一折り返し部２３Ａのターン部２３４の谷折り面に当接している。また、本実施形態の電極体２では、第二の第二部材２２Ｂの一方側の端部２２Ｄは、第二折り返し部２３Ｂのターン部２３４に当接している。具体的には、Ｙ軸方向において、セパレータ２２１の谷折り面に正極２２０の一方側の端部２２０Ｂが当接された折り曲げ部２２１０の山折り面は、第二折り返し部２３Ｂのターン部２３４の谷折り面に当接している。このように第一の第二部材２２Ａ及び第二の第二部材２２Ｂが、第一折り返し部２３Ａ又は第二折り返し部２３Ｂに当接した状態で、Ｘ軸方向に隣り合う平坦部２３３間のそれぞれに配置されることにより、正極２２０が、負極２１０の平坦部２３３の各面と対向した状態となる。   In the electrode body 2 of the present embodiment, the other end 22C of the first second member 22A is in contact with the turn portion 234 of the first folded portion 23A in the Y-axis direction. Specifically, in the Y-axis direction, the mountain fold surface of the bent portion 2210 in which the other end portion 220A of the positive electrode 220 is in contact with the valley fold surface of the separator 221 is the width of the turn portion 234 of the first folded portion 23A. It is in contact with the valley folding surface. In the electrode body 2 of the present embodiment, one end 22D of the second second member 22B is in contact with the turn portion 234 of the second folded portion 23B. Specifically, in the Y-axis direction, the mountain fold surface of the bent portion 2210 in which the end portion 220B on one side of the positive electrode 220 is in contact with the valley fold surface of the separator 221 is the fold surface of the turn portion 234 of the second turned portion 23B. It is in contact with the valley folding surface. In this way, the first second member 22A and the second second member 22B are in contact with the first folded portion 23A or the second folded portion 23B, respectively, between the flat portions 233 adjacent in the X-axis direction. As a result, the positive electrode 220 faces each surface of the flat portion 233 of the negative electrode 210.

本実施形態の電極体２では、第一の第二部材２２Ａの形状と第二の第二部材２２Ｂの形状とは同じである。そのため、本実施形態の各第二部材２２のＹ軸方向における寸法は同じである。   In the electrode body 2 of the present embodiment, the shape of the first second member 22A and the shape of the second second member 22B are the same. Therefore, the dimension in the Y-axis direction of each second member 22 of the present embodiment is the same.

また、本実施形態の電極体２では、第二部材２２のＹ軸方向における両端縁が、第一折り返し部２３Ａのターン部２３４の谷折り面及び第二折り返し部２３Ｂのターン部２３４谷折り面（負極２１０における平坦部２３３とターン部２３４との境界α）よりも内側に位置する。換言すると、本実施形態の電極体２では、正極２２０のＹ軸方向における寸法は、第一折り返し部２３Ａのターン部２３４の谷折り面から第二折り返し部２３Ｂのターン部２３４の谷折り面までのＹ軸方向における距離よりも小さい。   Further, in the electrode body 2 of the present embodiment, both end edges in the Y-axis direction of the second member 22 are the valley folded surface of the turn portion 234 of the first folded portion 23A and the turn portion 234 valley folded surface of the second folded portion 23B. It is located inside (a boundary α between the flat portion 233 and the turn portion 234 in the negative electrode 210). In other words, in the electrode body 2 of the present embodiment, the dimension of the positive electrode 220 in the Y-axis direction is from the valley folding surface of the turn portion 234 of the first folding portion 23A to the valley folding surface of the turn portion 234 of the second folding portion 23B. Is smaller than the distance in the Y-axis direction.

また、本実施形態の電極体２では、図１２に示すように、Ｙ軸方向において、第一の第二部材２２Ａにおける他方側の端縁２２Ｅから正極タブ２２５の中心２２５Ｃまでの距離をＬ１とし、第二の第二部材２２Ｂにおける一方側の端縁２２Ｆから正極タブ２２５の中心２２５Ｃまでの距離をＬ２とし、第一折り返し部２３Ａのターン部２３４の谷折り面から第二折り返し部２３Ｂのターン部２３４の谷折り面までの距離をＬ３とし、正極タブ２２５のＹ軸方向における幅をＴ１としたとき、以下の数式を満たす。
Ｌ３＞Ｔ１
Ｌ３−Ｔ１＜Ｌ１＋Ｌ２＜Ｌ３＋Ｔ１ In the electrode body 2 of the present embodiment, as shown in FIG. 12, the distance from the other end 22E of the first second member 22A to the center 225C of the positive electrode tab 225 in the Y-axis direction is L1. The distance from one end edge 22F of the second second member 22B to the center 225C of the positive electrode tab 225 is L2, and the turn of the second folded portion 23B from the valley folded surface of the turn portion 234 of the first folded portion 23A. When the distance to the valley fold surface of the portion 234 is L3 and the width of the positive electrode tab 225 in the Y-axis direction is T1, the following formula is satisfied.
L3> T1
L3-T1 <L1 + L2 <L3 + T1

電極体２が上記数式を満たすことで、正極タブ２２５の少なくとも一部は、Ｘ軸方向から見て重なる。尚、図１２では、正極タブ２２５の位置を明らかにするため、正極タブ２２５を黒色で塗って示している。   When the electrode body 2 satisfies the above formula, at least a part of the positive electrode tab 225 overlaps when viewed from the X-axis direction. In FIG. 12, in order to clarify the position of the positive electrode tab 225, the positive electrode tab 225 is shown in black.

また、正極タブ２２５の接合部のＹ軸方向における幅をＴ２とした場合、以下の数式を満たすことで、Ｙ軸方向において、正極タブ２２５の接合部の全体を正極タブ２２５と重なる大きさとすることができる。
Ｌ３＞（Ｔ１−Ｔ２）
Ｌ３−（Ｔ１−Ｔ２）＜Ｌ１＋Ｌ２＜Ｌ３＋（Ｔ１−Ｔ２）
尚、正極タブ２２５のＹ軸方向における幅Ｔ１は、例えば、５ｍｍ〜１５ｍｍ程度である。正極タブ２２５の接合部のＹ軸方向における幅Ｔ２は、例えば、１ｍｍ〜５ｍｍ程度である。 When the width in the Y-axis direction of the joint portion of the positive electrode tab 225 is T2, the entire joint portion of the positive electrode tab 225 overlaps the positive electrode tab 225 in the Y-axis direction by satisfying the following mathematical formula. be able to.
L3> (T1-T2)
L3- (T1-T2) <L1 + L2 <L3 + (T1-T2)
The width T1 of the positive electrode tab 225 in the Y-axis direction is, for example, about 5 mm to 15 mm. The width T2 in the Y-axis direction of the joint portion of the positive electrode tab 225 is, for example, about 1 mm to 5 mm.

具体的に、本実施形態の電極体２では、図１２に示すように、Ｙ軸方向において、第一の第二部材２２Ａにおける他方側の端縁２２Ｅから正極タブ２２５の中心２２５Ｃまでの距離Ｌ１と、第二の第二部材２２Ｂにおける一方側の端縁２２Ｆから正極タブ２２５の中心２２５Ｃまでの距離Ｌ２との和が、第一折り返し部２３Ａのターン部２３４の谷折り面から第二折り返し部２３Ｂのターン部２３４の谷折り面までの距離Ｌ３と等しい。尚、「Ｌ１とＬ２との和がＬ３と等しい」とは、Ｌ１とＬ２との和に製造誤差（０．５ｍｍ以内）を考慮した値がＬ３に等しい場合も含む。「Ｌ１とＬ２との和がＬ３と等しい」構成とすることにより、複数の正極タブ２２５同士が重なる面積を最大化することができるため、電極体２の電気抵抗を小さくすることができる。   Specifically, in the electrode body 2 of the present embodiment, as shown in FIG. 12, a distance L1 from the other end 22E of the first second member 22A to the center 225C of the positive electrode tab 225 in the Y-axis direction. And the sum of the distance L2 from the one end edge 22F of the second second member 22B to the center 225C of the positive electrode tab 225 is the second folded portion from the valley folded surface of the turn portion 234 of the first folded portion 23A. It is equal to the distance L3 to the valley folding surface of the turn part 234 of 23B. Note that “the sum of L1 and L2 is equal to L3” includes a case where a value in consideration of a manufacturing error (within 0.5 mm) is equal to L3 in the sum of L1 and L2. By adopting a configuration in which “the sum of L1 and L2 is equal to L3”, the area where the plurality of positive electrode tabs 225 overlap each other can be maximized, so that the electrical resistance of the electrode body 2 can be reduced.

本実施形態の第一の第二部材２２Ａの山折り面及び第二の第二部材２２Ｂの山折り面は、セパレータ２２１の端縁であり、上述のように、Ｘ軸方向における中央に位置する平坦な部分と、この平坦な部分の両側に位置し湾曲した部分とを有する。また、本実施形態の第一の第二部材２２Ａにおける他方側の端縁２２Ｅから正極タブ２２５の中心２２５Ｃまでの距離Ｌ１、及び、第二の第二部材２２Ｂにおける一方側の端縁２２Ｆから正極タブ２２５の中心２２５Ｃまでの距離Ｌ２は、いずれも、セパレータ２２１の一方側の端縁又はセパレータ２２１の一方側の端縁における中央に位置する平坦な部分から正極タブ２２５の中心２２５Ｃ（正極タブ２２５のＹ軸方向における中心２２５Ｃ）までの距離である。   The mountain fold surface of the first second member 22A and the mountain fold surface of the second second member 22B of the present embodiment are the edges of the separator 221, and are located at the center in the X-axis direction as described above. It has a flat part and a curved part located on both sides of this flat part. In addition, the distance L1 from the other end edge 22E of the first second member 22A of the present embodiment to the center 225C of the positive electrode tab 225, and the one end edge 22F of the second second member 22B to the positive electrode. The distance L2 from the center of the tab 225 to the center 225C is either a flat portion located at the center of one end edge of the separator 221 or the one end edge of the separator 221, and the center 225C of the positive electrode tab 225 (positive electrode tab 225). To the center 225C in the Y-axis direction.

尚、本実施形態の第一の第二部材２２Ａにおける他方側の端縁２２Ｅから正極タブ２２５の中心２２５Ｃまでの距離Ｌ１、及び、第二の第二部材２２Ｂにおける一方側の端縁２２Ｆから正極タブ２２５の中心２２５Ｃまでの距離Ｌ２は、正極タブ２２５のＹ軸方向における形成位置を異ならせることにより（具体的に、本体部２２４のＺ軸方向の一方の端縁における一方側の端部から正極タブ２２５が形成される第一の位置までの距離と、本体部２２４のＺ軸方向の一方の端縁における一方側の端部から正極タブ２２５が形成される第二の位置までの距離と、を異ならせることにより）、異ならせることができる。   Note that the distance L1 from the other end edge 22E of the first second member 22A of the present embodiment to the center 225C of the positive electrode tab 225 and the one end edge 22F of the second second member 22B to the positive electrode. The distance L2 to the center 225C of the tab 225 is determined by changing the formation position of the positive electrode tab 225 in the Y-axis direction (specifically, from one end of one end edge of the main body 224 in the Z-axis direction). The distance to the first position where the positive electrode tab 225 is formed, and the distance from the one end of the one end edge in the Z-axis direction of the main body 224 to the second position where the positive electrode tab 225 is formed Can be made different).

また、本実施形態の正極タブ２２５の中心は、正極タブ２２５のＹ軸方向における両端縁を基準とした中心（この両端縁からのＹ軸方向における距離が等しくなる中心）である。   Further, the center of the positive electrode tab 225 of the present embodiment is a center with respect to both end edges in the Y-axis direction of the positive electrode tab 225 (a center where distances in the Y-axis direction from both end edges are equal).

図１〜図３に戻り、ケース３は、開口を有するケース本体３１と、ケース本体３１の開口を塞ぐ（閉じる）蓋板３２と、を有する。このケース３では、ケース本体３１と蓋板３２とによって内部空間が画定される。ケース３は、この内部空間に、電極体２と共に電解液を収容する。このため、ケース３は、電解液に耐性を有する金属によって形成される。本実施形態のケース３は、例えば、アルミニウム、又は、アルミニウム合金等のアルミニウム系金属材料によって形成される。   Returning to FIGS. 1 to 3, the case 3 includes a case main body 31 having an opening and a lid plate 32 that closes (closes) the opening of the case main body 31. In the case 3, an internal space is defined by the case main body 31 and the lid plate 32. The case 3 accommodates the electrolyte together with the electrode body 2 in this internal space. For this reason, the case 3 is formed of a metal having resistance to the electrolytic solution. The case 3 of the present embodiment is formed of an aluminum metal material such as aluminum or an aluminum alloy, for example.

ケース本体３１は、板状の閉塞部３１１と、閉塞部３１１の周縁に接続される筒状の胴部（周壁）３１２と、を備える（図２参照）。   The case main body 31 includes a plate-like closing part 311 and a cylindrical body part (peripheral wall) 312 connected to the periphery of the closing part 311 (see FIG. 2).

閉塞部３１１は、ケース本体３１が開口を上に向けた姿勢で配置されたときにケース本体３１の下端に位置する（即ち、前記開口が上を向いたときのケース本体３１の底壁部となる）部位である。本実施形態の閉塞部３１１は、矩形状である。   The closing portion 311 is positioned at the lower end of the case body 31 when the case body 31 is arranged with the opening facing upward (ie, the bottom wall portion of the case body 31 when the opening faces upward). Part). The obstruction | occlusion part 311 of this embodiment is rectangular shape.

胴部３１２は、角筒形状、より詳しくは、偏平な角筒形状を有する。胴部３１２は、閉塞部３１１の周縁における長辺から延びる一対の長壁部３１３と、閉塞部３１１の周縁における短辺から延びる一対の短壁部３１４とを有する。短壁部３１４が一対の長壁部３１３の対応（詳しくは、Ｘ軸方向に対向）する端部同士をそれぞれ接続することによって、角筒状の胴部３１２が形成される。   The body portion 312 has a rectangular tube shape, more specifically, a flat rectangular tube shape. The body portion 312 has a pair of long wall portions 313 extending from the long side at the periphery of the closing portion 311 and a pair of short wall portions 314 extending from the short side at the periphery of the closing portion 311. By connecting the end portions of the short wall portion 314 corresponding to the pair of long wall portions 313 (specifically, facing each other in the X-axis direction), a rectangular tube-shaped body portion 312 is formed.

以上のように、ケース本体３１は、開口方向（Ｚ軸方向）における一方の端部が塞がれた角筒形状（即ち、有底角筒形状）を有する。このケース本体３１には、負極２１０の各平坦部２３３が長壁部３１３と平行（略平行）となる（即ち、各ターン部２３４が短壁部３１４と対向する）ように、電極体２が収容される。   As described above, the case body 31 has a rectangular tube shape (that is, a bottomed rectangular tube shape) in which one end portion in the opening direction (Z-axis direction) is closed. The case body 31 accommodates the electrode body 2 such that each flat portion 233 of the negative electrode 210 is parallel (substantially parallel) to the long wall portion 313 (that is, each turn portion 234 faces the short wall portion 314). Is done.

蓋板３２は、ケース本体３１の開口を塞ぐ部材である。この蓋板３２の輪郭形状は、ケース本体３１の開口周縁部３１０に対応した形状である。即ち、蓋板３２は、Ｘ軸方向に長い矩形状の板材である。   The lid plate 32 is a member that closes the opening of the case body 31. The outline shape of the cover plate 32 is a shape corresponding to the opening peripheral edge portion 310 of the case main body 31. That is, the lid plate 32 is a rectangular plate material that is long in the X-axis direction.

絶縁部材４は、電極体２の少なくとも一部を覆っている。本実施形態の絶縁部材４は、非多孔性のシートであり、絶縁性を有する樹脂によって形成されている。例えば、絶縁部材４は、ポリエチレン、ポリスチレン、ポリフェニレンサルファイド等によって形成されている。具体的に、絶縁部材４は、所定の形状に裁断された絶縁性を有するシート状の部材を折り曲げることによって蓋板３２側が開口した袋状に形成されている。   The insulating member 4 covers at least a part of the electrode body 2. The insulating member 4 of this embodiment is a non-porous sheet and is formed of a resin having insulating properties. For example, the insulating member 4 is made of polyethylene, polystyrene, polyphenylene sulfide, or the like. Specifically, the insulating member 4 is formed in a bag shape having an opening on the lid plate 32 side by bending an insulating sheet-like member cut into a predetermined shape.

また、本実施形態の絶縁部材４は、ケース本体３１に沿った形の袋状である。この袋状の絶縁部材４には、負極２１０の各平坦部２３３が絶縁部材４における長壁部３１３と対応する部位（Ｘ軸方向に対向する壁状の部位）と略平行となり、各ターン部２３４が絶縁部材４における短壁部３１４と対応する部位（Ｙ軸方向に対向する壁状の部位）と対向するように、電極体２が収容される。本実施形態の絶縁部材４は、蓋板３２側が開口した袋状であるため、電極体２が収容された状態では、Ｚ軸方向における電極体２の一方（図２における上側）の端部を開放した状態となっている。   Further, the insulating member 4 of the present embodiment has a bag shape along the case main body 31. In this bag-like insulating member 4, each flat portion 233 of the negative electrode 210 is substantially parallel to a portion corresponding to the long wall portion 313 (a wall-like portion facing in the X-axis direction) of the insulating member 4, and each turn portion 234. The electrode body 2 is accommodated so as to face a portion corresponding to the short wall portion 314 in the insulating member 4 (a wall-like portion facing the Y-axis direction). Since the insulating member 4 of the present embodiment has a bag shape with an opening on the cover plate 32 side, in the state in which the electrode body 2 is accommodated, one end (upper side in FIG. 2) of the electrode body 2 in the Z-axis direction is formed. It is in an open state.

外部端子５は、他の蓄電素子の外部端子又は外部機器等と電気的に接続される部位である。このため、外部端子５は、導電性を有する部材によって形成される。また、外部端子５は、溶接性の高い金属材料によって形成される。例えば、正極の外部端子５は、アルミニウム又はアルミニウム合金等のアルミニウム系金属材料によって形成され、負極の外部端子５は、銅又は銅合金等の銅系金属材料によって形成される。本実施形態の外部端子５は、少なくとも一部がケース３の外部に露出した状態で蓋板３２に取り付けられる。   The external terminal 5 is a part that is electrically connected to an external terminal of another power storage element or an external device. For this reason, the external terminal 5 is formed of a conductive member. The external terminal 5 is formed of a metal material having high weldability. For example, the positive external terminal 5 is formed of an aluminum-based metal material such as aluminum or an aluminum alloy, and the negative external terminal 5 is formed of a copper-based metal material such as copper or a copper alloy. The external terminal 5 of the present embodiment is attached to the cover plate 32 with at least a part thereof exposed to the outside of the case 3.

以上の蓄電素子１によれば、第二部材２２の端部（第一の第二部材２２Ａにおける他方側の端部２２Ｃ、第二の第二部材２２Ｂにおける一方側の端部２２Ｄ）は、第一折り返し部２３Ａ又は第二折り返し部２３Ｂのターン部２３４に当接しているため、第二部材２２がターン部２３４側に移動することを抑制できる。換言すると、第二部材２２が第一折り返し部２３Ａ又は第二折り返し部２３Ｂのターン部２３４により位置決めされているため、第一部材２１と第二部材２２とが位置ずれしにくい。   According to the power storage device 1 described above, the end portions of the second member 22 (the other end portion 22C of the first second member 22A and the one end portion 22D of the second second member 22B) Since the first folded portion 23A or the second folded portion 23B is in contact with the turn portion 234, the second member 22 can be prevented from moving toward the turn portion 234. In other words, since the second member 22 is positioned by the turn part 234 of the first folded part 23A or the second folded part 23B, the first member 21 and the second member 22 are not easily displaced.

また、本実施形態の電極体２では、第一部材２１に対して位置決めされている第二部材２２の端縁２２Ｅ、２２Ｆを基準として正極タブ２２５の位置を定めているため、第一の第二部材２２ＡのＹ軸方向における寸法や第二の第二部材２２ＢのＹ軸方向における端部の位置にかかわらず、第一の第二部材２２Ａと第二の第二部材２２Ｂとで正極タブ２２５同士の少なくとも一部を重ねることができる。   Moreover, in the electrode body 2 of this embodiment, since the position of the positive electrode tab 225 is defined on the basis of the edge 22E, 22F of the 2nd member 22 positioned with respect to the 1st member 21, 1st 1st Regardless of the size of the two members 22A in the Y-axis direction and the position of the end of the second second member 22B in the Y-axis direction, the positive tab 225 is composed of the first second member 22A and the second second member 22B. At least a part of each other can be overlapped.

より詳細に説明すると、第二部材２２の端部２２Ｃ、２２Ｄが第一折り返し部２３Ａ又は第二折り返し部２３Ｂのターン部２３４の谷折り面に当接している構成では、第一部材２１のターン部２３４の位置によって第一の第二部材２２Ａ及び第二の第二部材２２Ｂの端部２２Ｃ、２２Ｄの位置が定まることになる。このため、Ｘ軸方向から見て、第一の第二部材２２Ａの端部２２Ｃと第二の第二部材２２Ｂの端部２２Ｄとは、必ずしも一致しない。その結果、Ｘ軸方向から見て、第一の第二部材２２Ａにおける正極タブ２２５と第二の第二部材２２Ｂにおける正極タブ２２５とが重ならない場合があるという新たな課題が生じる。正極タブ２２５同士が重ならないと、正極タブ２２５同士の接合部位の面積を十分に確保できないことがある。   More specifically, in the configuration in which the end portions 22C and 22D of the second member 22 are in contact with the valley fold surface of the turn portion 234 of the first folded portion 23A or the second folded portion 23B, the turn of the first member 21 is turned on. The positions of the end portions 22C and 22D of the first second member 22A and the second second member 22B are determined by the position of the portion 234. For this reason, when viewed from the X-axis direction, the end 22C of the first second member 22A and the end 22D of the second second member 22B do not necessarily match. As a result, there is a new problem that the positive electrode tab 225 of the first second member 22A and the positive electrode tab 225 of the second second member 22B may not overlap each other when viewed from the X-axis direction. If the positive electrode tabs 225 do not overlap with each other, there may be a case where a sufficient area of the joint portion between the positive electrode tabs 225 cannot be secured.

これに対して、本実施形態の電極体２では、第一の第二部材２２Ａの他方側の端縁２２Ｅ（第一折り返し部２３Ａのターン部２３４に当接させる端縁）を基準とした距離や、第二の第二部材２２Ｂの一方側の端縁２２Ｆ（第二折り返し部２３Ｂのターン部２３４に当接させる端縁）を基準とした距離に応じて正極タブ２２５の位置を定めている。具体的には、電極体２は、Ｙ軸方向において、第一の第二部材２２Ａにおける他方側の端縁２２Ｅから正極タブ２２５の中心２２５Ｃまでの距離をＬ１とし、第二の第二部材２２Ｂにおける一方側の端縁２２Ｆから正極タブ２２５の中心２２５Ｃまでの距離をＬ２とし、第一折り返し部２３Ａのターン部２３４の谷折り面から第二折り返し部２３Ｂのターン部２３４の谷折り面までの距離をＬ３とし、正極タブ２２５のＹ軸方向における幅をＴ１としたとき、以下の数式を満たす（図１２参照）。
Ｌ３＞Ｔ１
Ｌ３−Ｔ１＜Ｌ１＋Ｌ２＜Ｌ３＋Ｔ１ On the other hand, in the electrode body 2 of the present embodiment, the distance based on the other end edge 22E of the first second member 22A (the end edge abutted against the turn portion 234 of the first folded portion 23A). Alternatively, the position of the positive electrode tab 225 is determined according to the distance based on the end edge 22F on one side of the second second member 22B (the end edge to be brought into contact with the turn portion 234 of the second folded portion 23B). . Specifically, in the electrode body 2, in the Y-axis direction, the distance from the other edge 22E of the first second member 22A to the center 225C of the positive electrode tab 225 is L1, and the second second member 22B The distance from one end edge 22F to the center 225C of the positive electrode tab 225 is L2, and from the valley fold surface of the turn portion 234 of the first turn-up portion 23A to the valley fold surface of the turn portion 234 of the second turn-up portion 23B When the distance is L3 and the width of the positive electrode tab 225 in the Y-axis direction is T1, the following formula is satisfied (see FIG. 12).
L3> T1
L3-T1 <L1 + L2 <L3 + T1

これにより、第一の第二部材２２ＡのＹ軸方向における寸法や第二の第二部材２２ＢのＹ軸方向における寸法にかかわらず、第一の第二部材２２Ａと第二の第二部材２２Ｂとで正極タブ２２５同士の少なくとも一部を重ねることができる。尚、第一折り返し部２３Ａのターン部２３４の谷折り面から第二折り返し部２３Ｂのターン部２３４の谷折り面までの距離Ｌ３は、第一折り返し部２３Ａのターン部２３４の谷折り面のうち最も内側に位置する点と、第二折り返し部２３Ｂのターン部２３４の谷折り面のうち最も内側に位置する点との間の距離である。   Thereby, regardless of the dimension in the Y-axis direction of the first second member 22A and the dimension in the Y-axis direction of the second second member 22B, the first second member 22A and the second second member 22B Thus, at least a part of the positive electrode tabs 225 can be overlapped. Note that the distance L3 from the valley fold surface of the turn portion 234 of the first fold portion 23A to the valley fold surface of the turn portion 234 of the second fold portion 23B is the valley fold surface of the turn portion 234 of the first fold portion 23A. This is the distance between the point located on the innermost side and the point located on the innermost side among the valley fold surfaces of the turn part 234 of the second folded part 23B.

さらに、本実施形態の電極体２では、セパレータ２２１の折り曲げ部２２１０の谷折り面が、正極２２０のＹ軸方向における他方側の端部２２０Ａ又は一方側の端部２２０Ｂを位置決めしているため、負極２１０と正極２２０との位置ずれを抑制できる。   Furthermore, in the electrode body 2 of the present embodiment, the valley fold surface of the bent portion 2210 of the separator 221 positions the other end portion 220A or one end portion 220B in the Y-axis direction of the positive electrode 220. Position shift between the negative electrode 210 and the positive electrode 220 can be suppressed.

より詳細に説明すると、正極２２０がセパレータ２２１に挟まれ、第二部材２２のＹ軸方向における両端がセパレータ２２１の第一出代部２２１３及び第二出代部２２１４である場合には、この第二部材２２の端部を第一部材２１の第一折り返し部２３Ａや第二折り返し部２３Ｂのターン部２３４の谷折り面に当接させても、位置決めが難しく、負極２１０と正極２２０との相対位置がずれるおそれがある。尚、位置決めが難しい理由は、セパレータ２２１の第一出代部２２１３及び第二出代部２２１４は、金属材料等の硬い部位を含んでおらず比較的やわらかいことから、当接させたターン部２３４側に向かって力がかかると曲がりやすいためである。   More specifically, when the positive electrode 220 is sandwiched between the separators 221 and both ends of the second member 22 in the Y-axis direction are the first protruding portion 2213 and the second protruding portion 2214 of the separator 221, Even if the end portions of the two members 22 are brought into contact with the valley fold surfaces of the first folded portion 23A of the first member 21 and the turn portion 234 of the second folded portion 23B, positioning is difficult, and the relative relationship between the negative electrode 210 and the positive electrode 220 There is a risk of displacement. The reason why the positioning is difficult is that the first protruding portion 2213 and the second protruding portion 2214 of the separator 221 do not include a hard portion such as a metal material and are relatively soft, so that the turn portion 234 that is in contact with the first protruding portion 2213 and the second protruding portion 2214 are not soft. This is because it is easy to bend when a force is applied toward the side.

これに対して、上記電極体２では、Ｙ軸方向において、谷折り面に正極２２０の端部２２０Ａ、２２０Ｂが当接されたセパレータ２２１の折り曲げ部２２１０の山折り面が、第一折り返し部２３Ａ又は第二折り返し部２３Ｂのターン部２３４の谷折り面に当接するため、セパレータ２２１の第一出代部２２１３や第二出代部２２１４が第一折り返し部２３Ａ又は第二折り返し部２３Ｂのターン部２３４の谷折り面に当接する構成よりも、正極２２０と負極２１０とが位置ずれしにくい。   On the other hand, in the electrode body 2, in the Y-axis direction, the mountain folded surface of the folded portion 2210 of the separator 221 in which the end portions 220A and 220B of the positive electrode 220 are in contact with the valley folded surface is the first folded portion 23A. Alternatively, the first protruding portion 2213 and the second protruding portion 2214 of the separator 221 are in contact with the valley folding surface of the turn portion 234 of the second folded portion 23B, so that the turn portion of the first folded portion 23A or the second folded portion 23B. The positive electrode 220 and the negative electrode 210 are less likely to be misaligned than the configuration in which the 234 contacts with the valley folding surface.

さらに、第二部材２２における第一部材２１（第一折り返し部２３Ａ又は第二折り返し部２３Ｂのターン部２３４の谷折り面）に当接している部位周辺は、第一部材２１に囲まれているため、電解液がしみ込みにくい傾向がある。これに対して、この構成では、第二部材２２における第一部材２１（第一折り返し部２３Ａ又は第二折り返し部２３Ｂのターン部２３４の谷折り面）に当接している部位周辺は、セパレータ２２１同士の接合箇所を不要とできるため、第一出代部２２１３や第二出代部２２１４のように二枚の部材が接合された部位が当接している場合よりも、電解液がしみ込みやすい。   Further, the first member 21 is surrounded by the first member 21 around the portion of the second member 22 that is in contact with the first member 21 (the valley folding surface of the turn portion 234 of the first folded portion 23A or the second folded portion 23B). Therefore, there is a tendency that the electrolytic solution is difficult to penetrate. In contrast, in this configuration, the periphery of the portion of the second member 22 that is in contact with the first member 21 (the valley folding surface of the turn portion 234 of the first folded portion 23A or the second folded portion 23B) is separated from the separator 221. Since it is possible to eliminate the need for a joint portion between the two, the electrolyte solution is more likely to be infiltrated compared to the case where the portions where the two members are joined, such as the first departure portion 2213 and the second departure portion 2214 are in contact. .

尚、本発明の蓄電素子は、上記実施形態に限定されるものではなく、本発明の要旨を逸脱しない範囲内において種々変更を加え得ることは勿論である。例えば、ある実施形態の構成に他の実施形態の構成を追加することができ、また、ある実施形態の構成の一部を他の実施形態の構成に置き換えることができる。さらに、ある実施形態の構成の一部を削除することができる。   In addition, the electrical storage element of this invention is not limited to the said embodiment, Of course, a various change can be added in the range which does not deviate from the summary of this invention. For example, the configuration of another embodiment can be added to the configuration of a certain embodiment, and a part of the configuration of a certain embodiment can be replaced with the configuration of another embodiment. Furthermore, a part of the configuration of an embodiment can be deleted.

上述したように、第二部材２２の端部２２Ｃ、２２Ｄが第一折り返し部２３Ａ又は第二折り返し部２３Ｂのターン部２３４の谷折り面に当接している構成では、第一部材２１のターン部２３４の位置（第一部材２１のターン部２３４のＹ軸方向における位置）によって第一の第二部材２２Ａ及び第二の第二部材２２Ｂの端部２２Ｃ、２２Ｄの位置が定まることになる。このため、Ｘ軸方向から見て、第一の第二部材２２Ａの一方側の端部２２Ｄと第二の第二部材２２Ｂの一方側の端部２２Ｄとは、必ずしも一致しない。その結果、Ｘ軸方向から見て、第一の第二部材２２Ａにおける正極タブ２２５と第二の第二部材２２Ｂにおける正極タブ２２５とが重ならない場合がある。これに対して、上記実施形態の蓄電素子１では、図１２に示したように、第二部材の形状を異ならせることで（例えば、第一の第二部材２２Ａの他方側の端縁２２Ｅを基準とした距離や、第二の第二部材２２Ｂの一方側の端縁２２Ｆを基準とした距離に応じて正極２２０の形状を異ならせることで）、正極タブ２２５の少なくとも一部を重ねたが、図１３に示すように、第一部材２１の折り返し部２３の谷折り面側のターン部２３４に、セパレータの第一出代部２２１３又は第二出代部２２１４を当接させると共に、ターン部２３４に当接されたセパレータ２２１の第一出代部２２１３又は第二出代部２２１４のＹ軸方向における長さを調節して正極タブ２２５同士の少なくとも一部を重ねてもよい。尚、図１３においても、正極タブ２２５の位置を明らかにするため、正極タブ２２５を黒色で塗って示している。   As described above, in the configuration in which the end portions 22C and 22D of the second member 22 are in contact with the valley fold surface of the turn portion 234 of the first turn-up portion 23A or the second turn-up portion 23B, the turn portion of the first member 21 The positions of the end portions 22C and 22D of the first second member 22A and the second second member 22B are determined by the position of 234 (the position of the turn portion 234 of the first member 21 in the Y-axis direction). For this reason, when viewed from the X-axis direction, the one end 22D of the first second member 22A does not necessarily match the one end 22D of the second second member 22B. As a result, when viewed from the X-axis direction, the positive electrode tab 225 of the first second member 22A and the positive electrode tab 225 of the second second member 22B may not overlap. On the other hand, in the electrical storage element 1 of the said embodiment, as shown in FIG. 12, by making the shape of a 2nd member different (for example, the edge 22E of the other side of 22 A of 1st 2nd members is used). At least a part of the positive electrode tab 225 is overlapped by changing the shape of the positive electrode 220 in accordance with the reference distance or the distance based on the one end edge 22F of the second second member 22B. As shown in FIG. 13, the first protruding portion 2213 or the second protruding portion 2214 of the separator is brought into contact with the turn portion 234 on the valley folding surface side of the folded portion 23 of the first member 21, and the turn portion At least a part of the positive electrode tabs 225 may be overlapped by adjusting the length in the Y-axis direction of the first protruding portion 2213 or the second protruding portion 2214 of the separator 221 in contact with the H.234. In FIG. 13 also, the positive electrode tab 225 is shown in black to clarify the position of the positive electrode tab 225.

具体的に、各正極２２０の形状が同じであることにより、各正極タブ２２５は、各本体部２２４のＺ軸方向の一方の端縁のうちＹ軸方向における同一の位置からＺ軸方向に延びていてもよい。各正極２２０のＹ軸方向における寸法は、第一折り返し部２３Ａのターン部２３４の谷折り面から第二折り返し部２３Ｂのターン部２３４の谷折り面までのＹ軸方向における距離よりも狭くてもよい。さらに、第一の第二部材２２Ａにおけるセパレータ２２１の他方側の端縁２２１Ｃから正極タブ２２５までの距離（例えば、第一の第二部材２２Ａにおけるセパレータ２２１の他方側の端縁２２１Ｃから正極タブ２２５の中心２２５Ｃまでの距離Ｌ４）と、第二の第二部材２２Ｂにおけるセパレータ２２１の一方側の端縁２２１Ｄから正極タブ２２５までの距離（例えば、第二の第二部材２２Ｂにおけるセパレータ２２１の一方側の端縁２２１Ｄから正極タブ２２５の中心２２５Ｃまでの距離Ｌ５）との和が、第一折り返し部２３Ａのターン部２３４の谷折り面から第二折り返し部２３Ｂのターン部２３４の谷折り面までの距離Ｘと等しくなるよう、第一折り返し部２３Ａのターン部２３４の谷折り面に当接されたセパレータ２２１の第二出代部２２１４（第一の第二部材２２Ａの第二出代部２２１４）のＹ軸方向における寸法Ｗ２と、第二折り返し部２３Ｂのターン部２３４の谷折り面に当接されたセパレータ２２１の第一出代部２２１３（第二の第二部材２２Ｂの第一出代部２２１３）のＹ軸方向における寸法Ｗ１とを調整してもよい。   Specifically, since each positive electrode 220 has the same shape, each positive electrode tab 225 extends in the Z-axis direction from the same position in the Y-axis direction among one end edge of each main body 224 in the Z-axis direction. It may be. The dimension in the Y-axis direction of each positive electrode 220 may be smaller than the distance in the Y-axis direction from the valley folding surface of the turn part 234 of the first folding part 23A to the valley folding surface of the turn part 234 of the second folding part 23B. Good. Further, a distance from the other end edge 221C of the separator 221 in the first second member 22A to the positive electrode tab 225 (for example, the other end edge 221C of the separator 221 in the first second member 22A to the positive electrode tab 225). And the distance from the edge 221D on one side of the separator 221 in the second second member 22B to the positive electrode tab 225 (for example, one side of the separator 221 in the second second member 22B). The distance L5) from the edge 221D to the center 225C of the positive electrode tab 225 is from the valley folding surface of the turn portion 234 of the first folding portion 23A to the valley folding surface of the turn portion 234 of the second folding portion 23B. The second exit of the separator 221 in contact with the valley fold surface of the turn portion 234 of the first turn-up portion 23A so as to be equal to the distance X. Dimension W2 in the Y-axis direction of the portion 2214 (second protruding portion 2214 of the first second member 22A) and the first of the separator 221 in contact with the valley fold surface of the turn portion 234 of the second folded portion 23B The dimension W1 in the Y-axis direction of the allowance portion 2213 (the first allowance portion 2213 of the second second member 22B) may be adjusted.

例えば、第一折り返し部２３Ａのターン部２３４Ａの谷折り面から第一の第二部材２２Ａの正極２２０の他端側の端縁２２０Ｃとの距離が、第二折り返し部２３Ｂのターン部２３４Ｂの谷折り面から第二の第二部材２２Ｂの正極２２０の一端側の端縁２２０Ｄとの距離と等しい場合には、第一出代部２２１３の寸法Ｗ１と第二出代部２２１４の寸法Ｗ２とを等しくすればよい。また、第一折り返し部２３Ａのターン部２３４Ａの谷折り面から第一の第二部材２２Ａの正極２２０の他端側の端縁２２０Ｃとの距離が、第二折り返し部２３Ｂのターン部２３４Ｂの谷折り面から第二の第二部材２２Ｂの正極２２０の一端側の端縁２２０Ｄとの距離よりも大きい場合には、これらの距離の差だけ、第二出代部２２１４の寸法Ｗ２を第一出代部２２１３の寸法Ｗ１よりも大きくすればよい。   For example, the distance from the valley folding surface of the turn part 234A of the first folded part 23A to the edge 220C on the other end side of the positive electrode 220 of the first second member 22A is the valley of the turn part 234B of the second folded part 23B. When the distance from the folding surface is equal to the edge 220D on the one end side of the positive electrode 220 of the second second member 22B, the dimension W1 of the first allowance portion 2213 and the dimension W2 of the second allowance portion 2214 are It only has to be equal. Further, the distance from the valley folding surface of the turn part 234A of the first folded part 23A to the edge 220C on the other end side of the positive electrode 220 of the first second member 22A is the valley of the turn part 234B of the second folded part 23B. When the distance from the folding surface is larger than the distance from the edge 220D on the one end side of the positive electrode 220 of the second second member 22B, the dimension W2 of the second protruding portion 2214 is increased by the difference between these distances. What is necessary is just to make it larger than the dimension W1 of the margin part 2213. FIG.

この構成では、セパレータ２２１の第一出代部２２１３や第二出代部２２１４のＹ軸方向における寸法を調整することで、正極タブ２２５の位置を定めているため、第一の第二部材２２Ａと第二の第二部材２２Ｂとで正極タブ２２５同士の位置を揃えることができる。   In this configuration, since the position of the positive electrode tab 225 is determined by adjusting the dimensions of the first protruding portion 2213 and the second protruding portion 2214 of the separator 221 in the Y-axis direction, the first second member 22A And the second second member 22B can align the positions of the positive electrode tabs 225 with each other.

また、図１４に示すように、Ｙ軸方向における一方側と他方側とに配置されたターン部２３４の谷折り面同士の距離及びセパレータ２２１のＹ軸方向における長さを調節して、同じ形状の正極２２０を用いつつ正極タブ２２５同士の少なくとも一部を重ねてもよい。尚、図１４においても、正極タブ２２５の位置を明らかにするため、正極タブ２２５を黒色で塗って示している。   Moreover, as shown in FIG. 14, the same shape is obtained by adjusting the distance between the valley fold surfaces of the turn portions 234 arranged on one side and the other side in the Y-axis direction and the length of the separator 221 in the Y-axis direction. At least a part of the positive electrode tabs 225 may be overlapped while using the positive electrode 220. In FIG. 14 as well, the positive electrode tab 225 is shown in black to clarify the position of the positive electrode tab 225.

この場合、各正極２２０の形状が同じであるため、各正極タブ２２５は、各本体部２２４のＺ軸方向の一方の端縁のうちＹ軸方向における同一の位置からＺ軸方向に延びていてもよい。また、第一折り返し部２３Ａのターン部２３４Ａの谷折り面と第二折り返し部２３Ｂのターン部２３４Ｂの谷折り面との間の距離）をＸとし、セパレータ２２１のＹ軸方向における長さをＹとし、正極タブ２２５の幅をＴ１としたとき、以下の数式を満たしてもよい。
２Ｘ＞Ｔ１
Ｘ−（Ｔ１／２）＜Ｙ＜Ｘ＋（Ｔ１／２） In this case, since the shape of each positive electrode 220 is the same, each positive electrode tab 225 extends in the Z-axis direction from the same position in the Y-axis direction of one end edge of each main body portion 224 in the Z-axis direction. Also good. Further, the distance between the valley folding surface of the turn part 234A of the first folding part 23A and the valley folding surface of the turn part 234B of the second folding part 23B is X, and the length of the separator 221 in the Y-axis direction is Y When the width of the positive electrode tab 225 is T1, the following mathematical formula may be satisfied.
2X> T1
X- (T1 / 2) <Y <X + (T1 / 2)

尚、第一折り返し部２３Ａのターン部２３４の谷折り面から第二折り返し部２３Ｂのターン部２３４の谷折り面までの距離Ｘは、第一折り返し部２３Ａのターン部２３４の谷折り面のうち最も内側に位置する点と、第二折り返し部２３Ｂのターン部２３４の谷折り面のうち最も内側に位置する点との間の距離である。また、セパレータ２２１のＹ軸方向における長さＹは、セパレータ２２１のＹ軸方向における一方側の端縁と他方側の端縁との距離である。   In addition, the distance X from the valley folding surface of the turn part 234 of the first folding part 23A to the valley folding surface of the turn part 234 of the second folding part 23B is the valley folding surface of the turn part 234 of the first folding part 23A. This is the distance between the point located on the innermost side and the point located on the innermost side among the valley fold surfaces of the turn part 234 of the second folded part 23B. The length Y of the separator 221 in the Y-axis direction is the distance between one end edge and the other end edge of the separator 221 in the Y-axis direction.

この構成では、第一折り返し部２３Ａと第二折り返し部２３Ｂの谷折り面同士の距離に応じてセパレータ２２１のＹ軸方向における長さを調整することで、異なる形状の正極２２０を用いることなく、第一の第二部材２２Ａと第二の第二部材２２Ｂとで正極タブ２２５同士の少なくとも一部を重ねることができる。   In this configuration, by adjusting the length of the separator 221 in the Y-axis direction according to the distance between the valley folded surfaces of the first folded portion 23A and the second folded portion 23B, without using the positive electrode 220 having a different shape, At least a part of the positive electrode tabs 225 can be overlapped with each other between the first second member 22A and the second second member 22B.

また、この場合、正極タブ２２５の接合部のＹ軸方向における幅をＴ２とすると、以下の数式を満たすことで、Ｙ軸方向において、正極タブ２２５の接合部の全体を正極タブ２２５と重なる大きさとすることができる。
２Ｘ＞（Ｔ１−Ｔ２）
Ｘ−｛（Ｔ１−Ｔ２）／２｝＜Ｙ＜Ｘ＋｛（Ｔ１−Ｔ２）／２｝ In this case, if the width in the Y-axis direction of the joint portion of the positive electrode tab 225 is T2, the following equation is satisfied so that the entire joint portion of the positive electrode tab 225 overlaps the positive electrode tab 225 in the Y-axis direction. It can be.
2X> (T1-T2)
X-{(T1-T2) / 2} <Y <X + {(T1-T2) / 2}

さらに、この場合、「ＹがＸと等しい」構成とすることにより、複数の正極タブ２２５同士が重なる面積を最大化することができるため、電極体２の電気抵抗を小さくすることができる。「ＹがＸと等しい」とは、Ｙに製造誤差（０．５ｍｍ以内）を考慮した値がＸに等しい場合も含む。   Furthermore, in this case, by adopting a configuration in which “Y is equal to X”, the area where the plurality of positive electrode tabs 225 overlap can be maximized, so that the electrical resistance of the electrode body 2 can be reduced. “Y is equal to X” includes the case where Y takes into account a manufacturing error (within 0.5 mm) equal to X.

さらに、セパレータ２２１の折り曲げ部２２１０がケース３の内部に当接していてもよい。   Further, the bent portion 2210 of the separator 221 may be in contact with the inside of the case 3.

具体的には、電極体２では、図１５に示すように、セパレータ２２１の折り曲げ部２２１０の谷折り面は、正極２２０の本体部２２４における正極タブ２２５が突出する側と反対側の端部２２０Ｆを覆ってもよい。   Specifically, in the electrode body 2, as shown in FIG. 15, the valley fold surface of the bent portion 2210 of the separator 221 is an end portion 220 </ b> F opposite to the side from which the positive electrode tab 225 protrudes in the main body portion 224 of the positive electrode 220. May be covered.

この場合、図１６に示すように、第一の第二部材２２Ａのセパレータ２２１における正極タブ２２５が突出する側と反対側の端部２２１５から正極タブ２２５が突出する位置２２１６（例えば、正極タブ２２５が突出する側の端縁２２１６）までのＺ軸方向における寸法Ｌ６は、第二の第二部材２２Ｂのセパレータ２２１における正極タブ２２５が突出する側と反対側の端部２２１５から正極タブ２２５が突出する位置２２１６までのＺ軸方向における寸法Ｌ６と同じであってもよい。また、この場合、第一の第二部材２２Ａの正極タブ２２５の突出量２２５Ａ（例えば、セパレータ２２１における正極タブ２２５が突出する側の端縁２２１６から正極タブ２２５における本体部２２４と反対側の端縁２２５ＢまでのＺ軸方向における寸法）は、第二の第二部材２２Ｂの正極タブ２２５の突出量２２５Ａと同じであってもよい。この場合、電極体２は、前記セパレータ２２１の折り曲げ部２２１０の山折り面をケース３の内面に直接または間接に当接させた状態で、ケース３内に配置されてもよい。また、第一部材２１のＺ軸方向における端部も、ケース３の内面に直接または間接に当接させた状態で、ケース３内に配置されてもよい。   In this case, as shown in FIG. 16, a position 2216 where the positive electrode tab 225 protrudes from an end 2215 opposite to the side where the positive electrode tab 225 protrudes in the separator 221 of the first second member 22A (for example, the positive electrode tab 225). The dimension L6 in the Z-axis direction up to the edge 2216) on the side from which the positive electrode tab protrudes is such that the positive electrode tab 225 protrudes from the end 2215 opposite to the side on which the positive electrode tab 225 protrudes in the separator 221 of the second second member 22B. It may be the same as the dimension L6 in the Z-axis direction up to the position 2216. Further, in this case, the protruding amount 225A of the positive electrode tab 225 of the first second member 22A (for example, the end of the positive electrode tab 225 opposite to the main body 224 from the edge 2216 of the separator 221 on the side where the positive electrode tab 225 protrudes). The dimension in the Z-axis direction up to the edge 225B) may be the same as the protruding amount 225A of the positive electrode tab 225 of the second second member 22B. In this case, the electrode body 2 may be disposed in the case 3 in a state where the mountain fold surface of the bent portion 2210 of the separator 221 is in direct or indirect contact with the inner surface of the case 3. Further, the end portion of the first member 21 in the Z-axis direction may also be disposed in the case 3 in a state of being in direct or indirect contact with the inner surface of the case 3.

この電極体２では、セパレータ２２１の正極タブ２２５が突出する側と反対側の端部２２１５（折り曲げ部２２１０）は、ケース３の内部に当接しているため、正極２２０の正極タブ２２５のＺ軸方向における位置を揃えることができる。   In this electrode body 2, the end 2215 (bending portion 2210) opposite to the side from which the positive electrode tab 225 protrudes of the separator 221 is in contact with the inside of the case 3, so the Z-axis of the positive electrode tab 225 of the positive electrode 220. The position in the direction can be aligned.

具体的に、この電極体２では、セパレータ２２１の折り曲げ部２２１０は、正極２２０におけるケース３の閉塞部３３１側の端縁（図９、図１０等における下側の端縁）を覆っていてもよい。   Specifically, in the electrode body 2, the bent portion 2210 of the separator 221 may cover the edge of the positive electrode 220 on the closing portion 331 side of the case 3 (the lower edge in FIGS. 9 and 10). Good.

より詳細に説明すると、ケース３内に電極体２及び電解液を収容した蓄電素子１において、正極２２０がセパレータ２２１に挟まれる場合、セパレータ２２１の折目方向の両端縁（二辺）の接合箇所に隙間が存在し、且つ、この隙間が正極２２０におけるケース３の閉塞部３１１側の端部の周辺に位置していると、ケース３の閉塞部３１１と正極２２０とがセパレータ２２１の隙間を介して導通して電流集中が生じる場合があった。   More specifically, when the positive electrode 220 is sandwiched between the separators 221 in the power storage device 1 in which the electrode body 2 and the electrolytic solution are housed in the case 3, the joining points of the two edges (two sides) in the fold direction of the separator 221. And the gap is located in the vicinity of the end of the positive electrode 220 on the closed portion 311 side of the case 3, the closed portion 311 of the case 3 and the positive electrode 220 pass through the gap of the separator 221. In some cases, current concentration occurs due to electrical conduction.

これに対して、電極体２では、図１４に示すように、セパレータ２２１の折り曲げ部２２１０の谷折り面は、正極２２０の本体部２２４におけるケース３の閉塞部３３１側に位置する端部２２０Ｆを覆ってもよい。この場合、電極体２は、前記セパレータ２２１の折り曲げ部２２１０の山折り面をケース３の閉塞部３３１に当接させた状態で、ケース３内に配置されてもよい。   On the other hand, in the electrode body 2, as shown in FIG. 14, the valley fold surface of the bent portion 2210 of the separator 221 has an end portion 220 </ b> F positioned on the closed portion 331 side of the case 3 in the main body portion 224 of the positive electrode 220. It may be covered. In this case, the electrode body 2 may be disposed in the case 3 in a state where the mountain fold surface of the bent portion 2210 of the separator 221 is in contact with the closing portion 331 of the case 3.

この電極体２では、ケース３の閉塞部３１１と正極２２０の端部２２０Ｆとの間にセパレータ２２１の折り曲げ部２２１０の折り目部位が介在しているため、この周辺（ケース３の閉塞部３１１と正極２２０の端部２２０Ｆとの間の周辺）にセパレータ２２１の接合箇所が存在しない。その結果、ケース３の閉塞部３１１と正極２２０との導通が抑制される。   In this electrode body 2, the crease part of the bent part 2210 of the separator 221 is interposed between the closed part 311 of the case 3 and the end part 220 F of the positive electrode 220. There is no joining point of the separator 221 in the vicinity of the end 220F of 220. As a result, conduction between the closed portion 311 of the case 3 and the positive electrode 220 is suppressed.

また、上述したように、第二部材２２の端部２２Ｃ、２２Ｄが第一折り返し部２３Ａ又は第二折り返し部２３Ｂのターン部２３４の谷折り面に当接している構成では、第一部材２１のターン部２３４の位置によって第一の第二部材２２Ａ及び第二の第二部材２２Ｂの端部２２Ｃ、２２Ｄの位置が定まることになる。このため、Ｘ軸方向から見て、第一の第二部材２２Ａの端部２２Ｃと第二の第二部材２２Ｂの端部２２Ｄとは、必ずしも一致しない。その結果、Ｘ軸方向から見て、第一の第二部材２２Ａにおける正極タブ２２５と第二の第二部材２２Ｂにおける正極タブ２２５とが重ならない場合がある。これに対して、上記実施形態の蓄電素子１では、図１２や図１３に示すような構成により、正極タブ２２５を重ねていたが、別の基準に応じて正極タブ２２５を重ねてもよい。   In addition, as described above, in the configuration in which the end portions 22C and 22D of the second member 22 are in contact with the valley folding surface of the turn portion 234 of the first folded portion 23A or the second folded portion 23B, The positions of the end portions 22C and 22D of the first second member 22A and the second second member 22B are determined by the position of the turn portion 234. For this reason, when viewed from the X-axis direction, the end 22C of the first second member 22A and the end 22D of the second second member 22B do not necessarily match. As a result, when viewed from the X-axis direction, the positive electrode tab 225 of the first second member 22A and the positive electrode tab 225 of the second second member 22B may not overlap. On the other hand, in the electricity storage device 1 of the above embodiment, the positive electrode tabs 225 are stacked according to the configuration shown in FIGS. 12 and 13, but the positive electrode tabs 225 may be stacked according to another standard.

具体的に、図１７に示すように、Ｙ軸方向において、第一の第二部材２２Ａの正極２２０と第二の第二部材２２Ｂの正極２２０とで、他方側の端縁２２０Ｃ同士の位置が異なると共に、第二部材２２の各々において正極２２０のＹ軸方向における寸法は等しく、正極２２０は、第一折り返し部２３Ａのターン部２３４の谷折り面と第二折り返し部２３Ｂのターン部２３４の谷折り面との間に（図１１における境界αの内側に）配置されてもよい。この場合、第一の第二部材２２Ａにおいて、正極タブ２２５（例えば、正極タブ２２５の中心２２５Ｃ）は、第一の第二部材２２Ａにおける正極２２０の他方側の端縁２２Ｅと第一の第二部材２２Ａにおける正極２２０の一方側の端縁２２０Ｄとの中心２２Ｇから一方側にずれており、正極タブ２２５のずれ量をＡとし、第一の第二部材２２Ａにおける正極２２０の他方側の端縁２２０Ｃと第二の第二部材２２Ｂにおける正極２２０の他方側の端縁２２０Ｃとの距離をＢとし、正極タブ２２５の幅をＴ１としたとき、以下の数式を満たしてもよい。
Ｂ＞Ｔ１（Ｂ／２）−（Ｔ１／２）＜Ａ＜（Ｂ／２）＋（Ｔ１／２）
また、第二の第二部材２２Ｂにおける正極２２０の形状は、第一の第二部材２２Ａにおける正極２２０の形状を反転させた形状と同一であってもよい。換言すると、第二の第二部材２２Ｂにおいて、正極タブ２２５（例えば、正極タブ２２５の中心２２５Ｃ）は、第二の第二部材２２Ｂにおける正極２２０の一方側の端縁２２０Ｄと第二の第二部材２２Ｂにおける正極２２０の他方側の端縁２２０Ｃとの中心２２Ｈから他方側にずれており、正極タブ２２５のずれ量をＣとし、第一の第二部材２２Ａにおける正極２２０の一方側の端縁２２０Ｄと第二の第二部材２２Ｂにおける正極２２０の一方側の端縁２２０Ｄとの距離をＤとし、正極タブ２２５の幅をＴ１としたときに、以下の数式を満たしてもよい。
Ｄ＞Ｔ１
（Ｄ／２）−（Ｔ１／２）＜Ｃ＜（Ｄ／２）＋（Ｔ／２）
尚、図１８においても、正極タブ２２５の位置を明らかにするため、正極タブ２２５を黒色で塗って示している。 Specifically, as shown in FIG. 17, in the Y-axis direction, the positions of the other end edges 220C of the positive electrode 220 of the first second member 22A and the positive electrode 220 of the second second member 22B are the same. In addition, the dimensions of the positive electrode 220 in each of the second members 22 in the Y-axis direction are the same, and the positive electrode 220 has a valley folded surface of the turn portion 234 of the first folded portion 23A and a valley of the turn portion 234 of the second folded portion 23B. You may arrange | position between the folding surfaces (inside the boundary (alpha) in FIG. 11). In this case, in the first second member 22A, the positive electrode tab 225 (for example, the center 225C of the positive electrode tab 225) is connected to the other edge 22E of the positive electrode 220 in the first second member 22A and the first second member 22A. The member 22A is shifted to one side from the center 22G with respect to the one end edge 220D of the positive electrode 220, and the shift amount of the positive electrode tab 225 is A, and the other end edge of the positive electrode 220 in the first second member 22A When the distance between 220C and the end 220C on the other side of the positive electrode 220 in the second second member 22B is B and the width of the positive electrode tab 225 is T1, the following mathematical formula may be satisfied.
B> T1 (B / 2)-(T1 / 2) <A <(B / 2) + (T1 / 2)
The shape of the positive electrode 220 in the second second member 22B may be the same as the shape obtained by inverting the shape of the positive electrode 220 in the first second member 22A. In other words, in the second second member 22B, the positive electrode tab 225 (for example, the center 225C of the positive electrode tab 225) is connected to the edge 220D on one side of the positive electrode 220 in the second second member 22B and the second second member 22B. The member 22B is shifted to the other side from the center 22H with respect to the other end edge 220C of the positive electrode 220, the shift amount of the positive electrode tab 225 is C, and the one end edge of the positive electrode 220 in the first second member 22A When the distance between 220D and the edge 220D on one side of the positive electrode 220 in the second second member 22B is D and the width of the positive electrode tab 225 is T1, the following mathematical formula may be satisfied.
D> T1
(D / 2)-(T1 / 2) <C <(D / 2) + (T / 2)
Also in FIG. 18, the positive electrode tab 225 is shown in black to clarify the position of the positive electrode tab 225.

また、正極タブ２２５の接合部のＹ軸方向における幅をＴ２とすると、以下の数式を満たすことで、Ｙ軸方向において、正極タブ２２５の接合部の全体を正極タブ２２５と重なる大きさとすることができる。
Ｂ＞Ｔ１−Ｔ２
（Ｂ／２）−｛（Ｔ１−Ｔ２）／２｝＜Ｃ＜（Ｂ／２）＋｛（Ｔ１−Ｔ２）／２｝ Also, assuming that the width in the Y-axis direction of the joint portion of the positive electrode tab 225 is T2, the entire joint portion of the positive electrode tab 225 overlaps with the positive electrode tab 225 in the Y-axis direction by satisfying the following mathematical formula. Can do.
B> T1-T2
(B / 2)-{(T1-T2) / 2} <C <(B / 2) + {(T1-T2) / 2}

この場合、第一の第二部材２２Ａ及び第二の第二部材２２Ｂにおいて、異なる形状の正極２２０を用いることなく、第一の第二部材２２Ａの正極２２０及び第二の第二部材２２Ｂの正極２２０で正極タブ２２５を重ねることができる。   In this case, in the first second member 22A and the second second member 22B, the positive electrode 220 of the first second member 22A and the positive electrode of the second second member 22B are used without using the positive electrodes 220 of different shapes. The positive electrode tab 225 can be overlaid at 220.

さらに、この場合、「Ｃが（Ｂ／２）と等しい」構成とすることにより、複数の正極タブ２２５同士が重なる面積を最大化することができるため、電極体２の電気抵抗を小さくすることができる。「Ｃが（Ｂ／２）と等しい」とは、Ｃに製造誤差（０．５ｍｍ以内）を考慮した値が（Ｂ／２）に等しい場合も含む。   Furthermore, in this case, by setting “C equal to (B / 2)”, the area where the plurality of positive electrode tabs 225 overlap each other can be maximized, so that the electrical resistance of the electrode body 2 can be reduced. Can do. The phrase “C is equal to (B / 2)” includes the case where the value of C considering a manufacturing error (within 0.5 mm) is equal to (B / 2).

上記実施形態の折り返し部２３のターン部２３４における山折り面及び谷折り面はいずれも、Ｘ軸方向における中央に位置する平坦な部分と、この平坦な部分の両側に位置し湾曲した部分とを有していたが、山折り面及び谷折り面の少なくとも一方が、全体的に湾曲していてもよい。例えば、ターン部２３４の谷折り面が全体的に湾曲している場合、第一折り返し部２３Ａのターン部２３４の谷折り面から第二折り返し部２３Ｂのターン部２３４の谷折り面までの距離は、第一折り返し部２３Ａのターン部２３４の谷折り面のうち最も外側に位置する点と、第二折り返し部２３Ｂのターン部２３４の谷折り面のうち最も外側に位置する点との距離であってもよい。   Each of the mountain fold surface and the valley fold surface in the turn portion 234 of the turn-up portion 23 of the above embodiment includes a flat portion located in the center in the X-axis direction and curved portions located on both sides of the flat portion. However, at least one of the mountain fold surface and the valley fold surface may be entirely curved. For example, when the valley folding surface of the turn part 234 is entirely curved, the distance from the valley folding surface of the turn part 234 of the first folding part 23A to the valley folding surface of the turn part 234 of the second folding part 23B is The distance between the point located on the outermost side of the valley fold surface of the turn portion 234 of the first folded portion 23A and the point located on the outermost side of the valley fold surface of the turn portion 234 of the second folded portion 23B. May be.

また、上記実施形態の図１２、図１３、図１７では、正極タブ２２５の位置を、正極タブ２２５の中心Ｃを定めることで定めたが、正極タブ２２５の位置を、正極タブ２２５のＹ軸方向における端縁等で定めてもよい。   12, 13, and 17 of the above embodiment, the position of the positive electrode tab 225 is determined by determining the center C of the positive electrode tab 225, but the position of the positive electrode tab 225 is determined by the Y axis of the positive electrode tab 225. It may be determined by an edge or the like in the direction.

例えば、図１２の代わりに、Ｙ軸方向において、第一の第二部材２２Ａにおける他方側の端縁２２Ｅから正極タブ２２５の他方側の端縁までの距離と、第二の第二部材２２Ｂにおける一方側の端縁２２Ｆから正極タブ２２５の他方側の端縁までの距離との和、又は、第一の第二部材２２Ａにおける他方側の端縁２２Ｅから正極タブ２２５の一方側の端縁までの距離と、第二の第二部材２２Ｂにおける一方側の端縁２２Ｆから正極タブ２２５の一方側の端縁までの距離との和、或いは、第一の第二部材２２Ａにおける他方側の端縁２２Ｅから正極タブ２２５の他方側の端縁までの距離と、正極タブ２２５における一方側の端縁から他方側の端縁までの距離と、第二の第二部材２２Ｂにおける一方側の端縁２２Ｆから正極タブ２２５の他方側の端縁までの距離との和が、第一折り返し部２３Ａのターン部２３４の谷折り面から第二折り返し部２３Ｂのターン部２３４の谷折り面までの距離と等しくてもよい。   For example, instead of FIG. 12, in the Y-axis direction, the distance from the other end edge 22E of the first second member 22A to the other end edge of the positive electrode tab 225, and the second second member 22B The sum of the distance from the one side edge 22F to the other edge of the positive electrode tab 225, or the other edge 22E of the first second member 22A to the one edge of the positive electrode tab 225 And the distance from one edge 22F of the second second member 22B to one edge of the positive electrode tab 225, or the other edge of the first second member 22A The distance from 22E to the other edge of the positive electrode tab 225, the distance from one edge of the positive electrode tab 225 to the other edge, and the one edge 22F of the second second member 22B To the other end of the positive electrode tab 225 The sum of the distances to may be equal to the distance from the valley-fold surface of the turn portion 234 of the first folded portion 23A to the valley fold surface of the turn portion 234 of the second folded portion 23B.

例えば、図１３の代わりに、Ｙ軸方向において、第一の第二部材２２Ａにおけるセパレータ２２１の他方側の端縁２２１Ｃからの正極タブ２２５の他方側の端縁までの距離と、第二の第二部材２２Ｂにおけるセパレータ２２１の一方側の端縁２２１Ｄから正極タブ２２５の他方側の端縁までの距離との和、又は、第一の第二部材２２Ａにおけるセパレータ２２１の他方側の端縁２２１Ｃからの正極タブ２２５の一方側の端縁までの距離と、第二の第二部材２２Ｂにおけるセパレータ２２１の一方側の端縁２２１Ｄから正極タブ２２５の一方側の端縁までの距離との和、或いは、第一の第二部材２２Ａにおけるセパレータ２２１の他方側の端縁２２１Ｃからの正極タブ２２５の他方側の端縁までの距離と、正極タブ２２５における一方側の端縁から他方側の端縁までの距離と、第二の第二部材２２Ｂにおけるセパレータ２２１の一方側の端縁２２１Ｄから正極タブ２２５の他方側の端縁までの距離との和が、第一折り返し部２３Ａのターン部２３４の谷折り面から第二折り返し部２３Ｂのターン部２３４の谷折り面までの距離と等しくなるよう、第一の第二部材２２Ａの第二出代部２２１４のＹ軸方向における寸法と、第二の第二部材２２Ｂの第一出代部２２１３のＹ軸方向における寸法と、を定めてもよい。   For example, instead of FIG. 13, in the Y-axis direction, the distance from the other end 221C of the separator 221 in the first second member 22A to the other end of the positive electrode tab 225, and the second second From the sum of the distance from one end edge 221D of the separator 221 in the two members 22B to the other end edge of the positive electrode tab 225, or from the other end edge 221C of the separator 221 in the first second member 22A And the sum of the distance to one edge of the positive electrode tab 225 and the distance from one edge 221D of the separator 221 to the one edge of the positive electrode tab 225 in the second second member 22B, or The distance from the other end edge 221C of the separator 221 in the first second member 22A to the other end edge of the positive electrode tab 225, and the one end edge in the positive electrode tab 225 The sum of the distance from the other edge to the other edge and the distance from the one edge 221D of the separator 221 to the other edge of the positive electrode tab 225 in the second second member 22B is the first folded portion. The second protruding portion 2214 of the first second member 22A in the Y-axis direction is equal to the distance from the valley folding surface of the turn portion 234 of 23A to the valley folding surface of the turn portion 234 of the second folded portion 23B. You may determine a dimension and the dimension in the Y-axis direction of the 1st protrusion part 2213 of the 2nd 2nd member 22B.

例えば、図１７の代わりに、第一の第二部材２２Ａにおいて、正極タブ２２５の一方側の端縁又は他方側の端縁は、第一の第二部材２２Ａにおける正極２２０他方側の端縁２２０Ｃと第一の第二部材２２Ａにおける正極２２０の一方側の端縁２２０Ｄとの中心２２Ｇから、第一の第二部材２２Ａにおける正極２２０の他方側の端縁２２０Ｃと第二の第二部材２２Ｂにおける正極２２０の他方側の端縁２２０Ｃとの距離Ｂの半分だけ一方側にずれており、第二の第二部材２２Ｂにおいて、正極タブ２２５の一方側の端縁又は他方側の端縁は、第二の第二部材２２Ｂにおける正極２２０の一方側の端縁２２０Ｄと第二の第二部材２２Ｂにおける正極２２０の他方側の端縁２２０Ｃとの中心２２Ｈから、第一の第二部材２２Ａにおける正極２２０の他方側の端縁２２０Ｃと第二の第二部材２２Ｂにおける正極２２０の他方側の端縁２２０Ｃとの距離Ｄの半分だけ他方側にずれていてもよい。   For example, instead of FIG. 17, in the first second member 22A, one end edge or the other end edge of the positive electrode tab 225 is the other end edge 220C of the positive electrode 220 in the first second member 22A. And from the center 22G of one end edge 220D of the positive electrode 220 in the first second member 22A to the other end edge 220C of the positive electrode 220 in the first second member 22A and the second second member 22B. It is shifted to one side by a half of the distance B from the other end edge 220C of the positive electrode 220. In the second second member 22B, one end edge or the other end edge of the positive electrode tab 225 is The positive electrode 220 in the first second member 22A from the center 22H between the one end edge 220D of the positive electrode 220 in the second second member 22B and the other end edge 220C of the positive electrode 220 in the second second member 22B. of Only half the distance D between the other side edge 220C of the positive electrode 220 square side edge 220C and in the second of the second member 22B may be shifted to the other side.

また、上記実施形態の蓄電素子１では、各第二部材２２のＹ軸方向における寸法は、同じであったが、これは異なっていてもよい。また、上記実施形態の蓄電素子１では、第二部材２２は、Ｙ軸方向の各端縁が負極の平坦部２３３とターン部２３４との境界αよりも内側に位置していたが、第二部材２２は、Ｙ軸方向の各端縁が負極の平坦部２３３とターン部２３４との境界αに位置してもよいし、Ｙ軸方向の各端縁が負極の平坦部２３３とターン部２３４との境界αよりも外側に位置してもよい。換言すると、正極２２０のＹ軸方向における寸法は、第一折り返し部２３Ａの谷折り面側のターン部２３４から第二折り返し部２３Ｂの谷折り面側のターン部２３４までのＹ軸方向における距離よりも狭かったが、第一折り返し部２３Ａの谷折り面側のターン部２３４から第二折り返し部２３Ｂの谷折り面側のターン部２３４までのＹ軸方向における距離と同じであってもよいし、この距離より広くてもよい。   Moreover, in the electrical storage element 1 of the said embodiment, although the dimension in the Y-axis direction of each 2nd member 22 was the same, this may differ. In the electricity storage device 1 of the above embodiment, the second member 22 has each edge in the Y-axis direction positioned on the inner side of the boundary α between the flat portion 233 and the turn portion 234 of the negative electrode. Each edge of the member 22 in the Y-axis direction may be positioned at a boundary α between the flat portion 233 and the turn portion 234 of the negative electrode, and each edge in the Y-axis direction may be positioned at the negative portion of the flat portion 233 and the turn portion 234. It may be located outside the boundary α. In other words, the dimension of the positive electrode 220 in the Y-axis direction is based on the distance in the Y-axis direction from the turn part 234 on the valley folded surface side of the first folded part 23A to the turn part 234 on the valley folded surface side of the second folded part 23B. Although it was narrow, it may be the same as the distance in the Y-axis direction from the turn part 234 on the valley folded surface side of the first folded part 23A to the turn part 234 on the valley folded surface side of the second folded part 23B. It may be wider than this distance.

さらに、上記実施形態の正極タブ２２５は、Ｘ軸方向に長い矩形状であったが、Ｙ軸方向に長い矩形状や正方形状等その他の形状であってもよい。また、上記実施形態の正極タブ２２５同士は、一箇所で接合されていたが、複数箇所で接合されていてもよい。尚、各正極タブ２２５の面積は、接合箇所よりも広いことが好ましい。また、各正極タブ２２５同士は、溶着等により接合される代わりに、クリップ等により束ねられていてもよい。   Furthermore, although the positive electrode tab 225 of the above embodiment has a rectangular shape that is long in the X-axis direction, it may have other shapes such as a rectangular shape or a square shape that is long in the Y-axis direction. Moreover, although the positive electrode tabs 225 of the said embodiment were joined in one place, you may join in multiple places. In addition, it is preferable that the area of each positive electrode tab 225 is wider than a joining location. Further, the positive electrode tabs 225 may be bundled by clips or the like instead of being joined by welding or the like.

上記実施形態のセパレータ２２１は、折り曲げ部２２１０を含んでいたが、折り曲げ部２２１０を含まない構成、例えば、第一被覆部２２１１を含むシート状の第一部材と、第二被覆部２２１２を含むシート状の第二部材とを接合して形成された構成であってもよい。この場合においても、セパレータ２２１は、第一出代部２２１３及び第二出代部２２１４を含んでいてもよい。また、セパレータ２２１同士は接合されていなくてもよい。   The separator 221 of the above embodiment includes the bent portion 2210, but does not include the bent portion 2210, for example, a sheet-like first member including the first covering portion 2211 and a sheet including the second covering portion 2212. The structure formed by joining the shape-like 2nd member may be sufficient. Also in this case, the separator 221 may include a first allowance portion 2213 and a second allowance portion 2214. Moreover, the separators 221 do not need to be joined.

また、上記実施形態の折り曲げ部２２１０の山折り面は、全体的に湾曲していてもよい。この場合、セパレータ２２１の折り曲げ部を含む端縁は、折り曲げ部２２１０の山折り面のうち最も外側に位置する点であってもよい。さらに、上記実施形態の折り曲げ部２２１０の谷折り面は、全体的に湾曲していてもよく、Ｘ軸方向における中央に位置する平坦な部分と、この平坦な部分の両側に位置し湾曲した部分とを有してもよい。   Moreover, the mountain fold surface of the bending part 2210 of the said embodiment may be curving as a whole. In this case, the end edge including the bent portion of the separator 221 may be a point located on the outermost side among the mountain fold surfaces of the bent portion 2210. Furthermore, the valley folding surface of the bent portion 2210 of the above embodiment may be entirely curved, and a flat portion located at the center in the X-axis direction and a curved portion located on both sides of the flat portion. You may have.

上記実施形態の蓄電素子１では、第一部材２１が負極２１０で構成され、第二部材２２が正極２２０及びセパレータ２２１で構成されていたが、セパレータ２２１は第一部材２１に含まれていてもよい。この場合、セパレータ２２１は、負極２１０と同様のつづら折り状（複数の折り返し部を有するつづら折り状）であってもよい。長尺な電極に沿ってセパレータ２５が配置される場合には、該セパレータ２５は、第一部材２１に含まれ、矩形状の電極に沿ってセパレータ２５が配置される場合には、該セパレータ２５は、第二部材２２に含まれる。   In the electricity storage device 1 of the above embodiment, the first member 21 is configured by the negative electrode 210 and the second member 22 is configured by the positive electrode 220 and the separator 221, but the separator 221 may be included in the first member 21. Good. In this case, the separator 221 may have a zigzag shape (zigzag shape having a plurality of folded portions) similar to that of the negative electrode 210. When the separator 25 is disposed along the long electrode, the separator 25 is included in the first member 21. When the separator 25 is disposed along the rectangular electrode, the separator 25 is disposed. Is included in the second member 22.

また、上記実施形態の蓄電素子１では、正極２２０を挟み込んだ状態のセパレータ２２１は、Ｘ軸方向から見て矩形状であり、Ｚ軸方向の寸法は、負極２１０の平坦部２３３の寸法より大きく、Ｙ軸方向の寸法は、平坦部２３３の寸法と比べて小さかったが、Ｚ軸方向の寸法は、負極２１０の平坦部２３３の寸法と比べて略同じ又は小さくてもよく、Ｙ軸方向の寸法は、平坦部２３３の寸法と比べて略同じであってもよい。   In the electricity storage device 1 of the above embodiment, the separator 221 with the positive electrode 220 sandwiched is rectangular when viewed from the X-axis direction, and the dimension in the Z-axis direction is larger than the dimension of the flat portion 233 of the negative electrode 210. The dimension in the Y-axis direction is smaller than the dimension of the flat part 233, but the dimension in the Z-axis direction may be substantially the same or smaller than the dimension of the flat part 233 of the negative electrode 210. The dimensions may be substantially the same as the dimensions of the flat portion 233.

さらに、上記実施形態の蓄電素子１では、負極２１０が複数の折り返し部２３を有するつづら折り状態であり、正極２２０が短冊状であるが、互いが逆の構成、即ち、正極２２０が複数の折り返し部２３を有するつづら折り状態であり、負極２１０が短冊状でもよい。   Furthermore, in the electricity storage device 1 of the above-described embodiment, the negative electrode 210 is in a zigzag folded state having a plurality of folded portions 23 and the positive electrode 220 has a strip shape, but the configuration is reversed, that is, the positive electrode 220 has a plurality of folded portions. 23, and the negative electrode 210 may have a strip shape.

上記実施形態においては、蓄電素子が充放電可能な非水電解質二次電池（例えばリチウムイオン二次電池）として用いられる場合について説明したが、蓄電素子の種類や大きさ（容量）は任意である。また、上記実施形態において、蓄電素子の一例として、リチウムイオン二次電池について説明したが、これに限定されるものではない。例えば、本発明は、種々の二次電池、その他、一次電池や、電気二重層キャパシタ等のキャパシタの蓄電素子にも適用可能である。   In the said embodiment, although the case where it was used as a nonaqueous electrolyte secondary battery (for example, lithium ion secondary battery) in which an electrical storage element can be charged / discharged was demonstrated, the kind and magnitude | size (capacity | capacitance) of an electrical storage element are arbitrary. . Moreover, in the said embodiment, although the lithium ion secondary battery was demonstrated as an example of an electrical storage element, it is not limited to this. For example, the present invention can be applied to various secondary batteries, other primary batteries, and power storage elements of capacitors such as electric double layer capacitors.

蓄電素子（例えば電池）１は、図１８に示すような蓄電装置（蓄電素子が電池の場合は電池モジュール）１１に用いられてもよい。蓄電装置１１は、少なくとも二つの蓄電素子１と、二つの（異なる）蓄電素子１同士を電気的に接続するバスバ部材１２と、を有する。この場合、本発明の技術が少なくとも一つの蓄電素子１に適用されていればよい。   The power storage element (for example, battery) 1 may be used in a power storage device 11 (a battery module when the power storage element is a battery) 11 as shown in FIG. The power storage device 11 includes at least two power storage elements 1 and a bus bar member 12 that electrically connects two (different) power storage elements 1 to each other. In this case, the technique of the present invention only needs to be applied to at least one power storage element 1.

１…蓄電素子、２…電極体、２１…第一部材、２１Ａ…山折り線、２１Ｂ…谷折り線、２１０…負極（第一の電極）、２１１…金属箔、２１２…負極活物質層、２２…第二部材、２２Ａ…第一の第二部材、２２Ｂ…第二の第二部材、２２Ｃ、２２Ｄ…端部、２２Ｅ、２２Ｆ…端縁、２２０…正極（第二の電極）、２２０Ａ、２２０Ｂ、２２０Ｆ…端部、２２０Ｃ、２２０Ｄ…端縁、２２１…セパレータ、２２１０…折り曲げ部、２２１１…第一被覆部、２２１２…第二被覆部、２２１３…第一出代部、２２１４…第二出代部、２２１５…端部、２２１６…位置、２２２…金属箔、２２３…正極活物質層、２２４…本体部、２２４Ａ、２２４Ｂ…端縁、２２５…正極タブ、２２５Ａ…突出量、２２５Ｃ…中心、２２５Ｂ…端縁、２３…折り返し部、２３Ａ…第一折り返し部、２３Ｂ…第二折り返し部、２３１…谷折り面、２３２…山折り面、２３３、２３３Ａ、２３３Ｂ…平坦部、２３３１…平坦部本体、２３３２…負極タブ、２３４…ターン部、２３４Ｓ…折り返し軸、３…ケース、３１…ケース本体、３１０…開口周縁部、３１１…閉塞部、３１２…胴部、３１３…長壁部、３１４…短壁部、３２…蓋板、４…絶縁部材、５…外部端子、６…集電体、１１…蓄電装置、１２…バスバ部材、１０２…電極体、１２１…負極・セパレータ圧着体、１２２…正極、１２３…セパレータ、１２４…負極体、α…平坦部とターン部との境界   DESCRIPTION OF SYMBOLS 1 ... Power storage element, 2 ... Electrode body, 21 ... First member, 21A ... Mountain fold line, 21B ... Valley fold line, 210 ... Negative electrode (first electrode), 211 ... Metal foil, 212 ... Negative electrode active material layer, 22 ... second member, 22A ... first second member, 22B ... second second member, 22C, 22D ... end, 22E, 22F ... end edge, 220 ... positive electrode (second electrode), 220A, 220B, 220F ... end, 220C, 220D ... end edge, 221 ... separator, 2210 ... bent part, 2211 ... first covering part, 2212 ... second covering part, 2213 ... first exiting part, 2214 ... second exit Substrate, 2215 ... end, 2216 ... position, 222 ... metal foil, 223 ... positive electrode active material layer, 224 ... main body, 224A, 224B ... edge, 225 ... positive electrode tab, 225A ... protrusion amount, 225C ... center, 225B ... edge, 23 ... turned back , 23A ... first folded portion, 23B ... second folded portion, 231 ... valley folded surface, 232 ... mountain folded surface, 233, 233A, 233B ... flat portion, 2331 ... flat portion main body, 2332 ... negative electrode tab, 234 ... turn Part, 234S ... folding axis, 3 ... case, 31 ... case main body, 310 ... opening peripheral part, 311 ... closing part, 312 ... trunk part, 313 ... long wall part, 314 ... short wall part, 32 ... cover plate, 4 ... Insulating member, 5 ... external terminal, 6 ... current collector, 11 ... power storage device, 12 ... bus bar member, 102 ... electrode body, 121 ... negative electrode / separator crimped body, 122 ... positive electrode, 123 ... separator, 124 ... negative electrode body, α: Boundary between flat part and turn part

Claims (6)

第一の電極を含むと共に、第一方向における一方側を開放するようにターン部で折り返された第一折り返し部、及び、前記第一方向における他方側を開放するようにターン部で折り返された第二折り返し部が交互に配されるようつづら折りされた長尺の第一部材と、
前記第一の電極と極性の異なる第二の電極を含み且つ前記第一折り返し部の内側に配置された第一の第二部材、及び、前記第二の電極を含み且つ前記第二折り返し部の内側に配置された第二の第二部材を含む複数の第二部材と、
を有する電極体
を備え、
前記第一の第二部材の前記他方側の端部は、前記第一折り返し部の前記ターン部に当接し、
前記第二の第二部材の前記一方側の端部は、前記第二折り返し部の前記ターン部に当接する、蓄電素子。 The first folded portion including the first electrode and folded at the turn portion so as to open one side in the first direction, and folded at the turn portion so as to open the other side in the first direction A long first member that is spelled so that the second folded portions are alternately arranged;
A first second member including a second electrode having a polarity different from that of the first electrode and disposed inside the first folded portion; and a second second member including the second electrode and the second folded portion. A plurality of second members including a second second member disposed inside;
An electrode body having
The other end portion of the first second member abuts on the turn portion of the first folded portion,
The one end of the second second member is in contact with the turn portion of the second folded portion. 前記第二の電極は、本体部と、該本体部から前記第一方向及び前記複数の第二部材が並ぶ方向のいずれにも直交する第二方向に突出するタブ部とを含み、
前記第一方向において、
前記第一の第二部材における前記他方側の端縁から前記タブ部の中心までの距離をＬ１とし、前記第二の第二部材における前記一方側の端縁から前記タブ部の中心までの距離をＬ２とし、前記第一折り返し部の前記ターン部の谷折り面から前記第二折り返し部の前記ターン部の谷折り面までの距離をＬ３とし、前記タブ部の幅をＴ１としたとき、以下の数式を満たす、請求項１に記載の蓄電素子。
Ｌ３＞Ｔ１
Ｌ３−Ｔ１＜Ｌ１＋Ｌ２＜Ｌ３＋Ｔ１ The second electrode includes a main body part and a tab part protruding from the main body part in a second direction orthogonal to both the first direction and the direction in which the plurality of second members are arranged,
In the first direction,
The distance from the other end edge of the first second member to the center of the tab portion is L1, and the distance from the one end edge of the second second member to the center of the tab portion is L1. Is L2, the distance from the valley fold surface of the turn portion of the first folded portion to the valley fold surface of the turn portion of the second folded portion is L3, and the width of the tab portion is T1, The electrical storage element of Claim 1 which satisfy | fills numerical formula.
L3> T1
L3-T1 <L1 + L2 <L3 + T1 前記第二の電極は、板状の本体部と、該本体部から前記第一方向及び前記複数の第二部材が並ぶ方向のいずれにも直交する第二方向に突出するタブ部とを含み、
前記複数の第二部材の各々は、前記本体部を挟むセパレータを有し、
前記第一の第二部材の形状と前記第二の第二部材の形状とは同じであり、
前記第一方向において、
前記第一部材における前記第一折り返し部の前記ターン部の谷折り面と前記第一部材における前記第二折り返し部の前記ターン部の谷折り面との間の距離をＸとし、前記セパレータの長さをＹとし、前記タブ部の幅をＴ１としたとき、以下の数式を満たす、請求項１に記載の蓄電素子。
２Ｘ＞Ｔ１、
Ｘ−（Ｔ１／２）＜Ｙ＜Ｘ＋（Ｔ１／２） The second electrode includes a plate-like main body portion, and a tab portion protruding from the main body portion in a second direction orthogonal to both the first direction and the direction in which the plurality of second members are arranged,
Each of the plurality of second members has a separator sandwiching the main body portion,
The shape of the first second member and the shape of the second second member are the same,
In the first direction,
The distance between the valley fold surface of the turn portion of the first folded portion of the first member and the valley fold surface of the turn portion of the second folded portion of the first member is X, and the length of the separator The electricity storage device according to claim 1, wherein Y is the thickness, and the width of the tab portion is T1, which satisfies the following mathematical formula.
2X> T1,
X- (T1 / 2) <Y <X + (T1 / 2) 前記電極体を含むケースを備え、
前記複数の第二部材の各々は、折り曲げ部を含むセパレータであって、前記第二の電極を挟むセパレータと、該セパレータから前記第一方向及び前記複数の第二部材が並ぶ方向のいずれにも直交する第二方向に突出するタブ部であって前記第二の電極の一部であるタブ部とを含み、
前記第二方向において、
前記第一の第二部材の前記セパレータにおける前記タブ部が突出する側と反対側の端部から前記タブ部が突出する位置までの寸法は、前記第二の第二部材の前記セパレータにおける前記タブ部が突出する側と反対側の端部から前記タブ部が突出する位置までの寸法と同じであり、
前記第一の第二部材の前記タブ部の突出量は、前記第二の第二部材の前記タブ部の突出量と同じであり、
前記折り曲げ部の谷折り面は、前記第二の電極の前記本体部における前記タブ部が突出する側と反対の端部を覆い、
前記電極体は、前記セパレータの前記折り曲げ部の山折り面を前記ケースの内面に直接または間接に当接させた状態で、前記ケース内に配置されている、請求項１〜３のいずれか１項に記載の蓄電素子。 A case including the electrode body;
Each of the plurality of second members is a separator including a bent portion, and both the separator sandwiching the second electrode and the first direction and the direction in which the plurality of second members are arranged from the separator. A tab portion protruding in a second direction orthogonal to each other, and a tab portion that is a part of the second electrode,
In the second direction,
The dimension from the end of the first second member opposite to the side where the tab portion protrudes to the position where the tab portion protrudes is the tab of the separator of the second second member. It is the same as the dimension from the end opposite to the side from which the part protrudes to the position where the tab part protrudes,
The protruding amount of the tab portion of the first second member is the same as the protruding amount of the tab portion of the second second member,
The valley fold surface of the bent portion covers the end opposite to the side from which the tab portion protrudes in the main body portion of the second electrode,
4. The electrode assembly according to claim 1, wherein the electrode body is disposed in the case in a state in which a mountain fold surface of the bent portion of the separator is in direct or indirect contact with an inner surface of the case. The electricity storage device according to item. 前記複数の第二部材の各々は、折り曲げ部を含むセパレータであって、前記第二の電極を挟むセパレータを有し、
前記第一の第二部材において、
前記第二の電極の前記他方側の端部は、前記セパレータの前記折り曲げ部の谷折り面に当接し、
前記セパレータの前記折り曲げ部の山折り面は、前記第一折り返し部の前記ターン部に当接し、
前記第二の第二部材において、
前記第二の電極の前記一方側の端部は、前記セパレータの前記折り曲げ部の谷折り面に当接し、
前記セパレータの前記折り曲げ部の山折り面は、前記第二折り返し部の前記ターン部に当接する、請求項１〜４のいずれか１項に記載の蓄電素子。 Each of the plurality of second members is a separator including a bent portion, and has a separator sandwiching the second electrode,
In the first second member,
The other end of the second electrode is in contact with the valley fold surface of the bent portion of the separator,
The mountain fold surface of the bent portion of the separator abuts on the turn portion of the first folded portion,
In the second second member,
The one end of the second electrode is in contact with the valley fold surface of the bent portion of the separator,
The storage element according to any one of claims 1 to 4, wherein a mountain fold surface of the bent portion of the separator is in contact with the turn portion of the second folded portion. 前記第二の電極は、本体部と、該本体部から前記第一方向及び前記複数の第二部材が並ぶ方向のいずれにも直交する第二方向に突出するタブ部とを含み
前記第一方向において、
前記第一の第二部材における前記第二の電極と前記第二の第二部材における前記第二の電極とで、前記他方側の端縁同士の位置が異なり、
前記第二の第二部材における前記第二の電極の形状は、前記第一の第二部材における前記第二の電極を反転させた形状と同一であり、
前記第一の第二部材において、
前記タブ部は、前記第一の第二部材における前記第二の電極の前記他方側の端縁と前記第一の第二部材における前記第二の電極の前記一方側の端縁との中心から、前記一方側にずれており、
前記タブ部のずれ量をＡとし、前記第一の第二部材における前記第二の電極の前記他方側の端縁と前記第二の第二部材における前記第二の電極の前記他方側の端縁との距離をＢとし、前記タブ部の幅をＴ１としたとき、以下の数式を満たす、請求項５に記載の蓄電素子。
Ｂ＞Ｔ１
（Ｂ／２）−（Ｔ１／２）＜Ａ＜（Ｂ／２）＋（Ｔ１／２） The second electrode includes a main body portion and a tab portion protruding from the main body portion in a second direction orthogonal to both the first direction and the direction in which the plurality of second members are arranged. In
In the second electrode in the first second member and the second electrode in the second second member, the positions of the edges on the other side are different,
The shape of the second electrode in the second second member is the same as the inverted shape of the second electrode in the first second member,
In the first second member,
The tab portion is formed from the center of the other end edge of the second electrode in the first second member and the one end edge of the second electrode in the first second member. , Shifted to the one side,
The deviation amount of the tab portion is A, and the other end of the second electrode in the first second member and the other end of the second electrode in the second second member. The storage element according to claim 5, wherein a distance from the edge is B and a width of the tab portion is T1, and the following mathematical formula is satisfied.
B> T1
(B / 2)-(T1 / 2) <A <(B / 2) + (T1 / 2)
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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04167375A (en) * 1990-10-30 1992-06-15 Toyo Takasago Kandenchi Kk Rectangular lithium secondary cell
JP2014103082A (en) * 2012-11-22 2014-06-05 Denso Corp Power storage element and manufacturing method thereof

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04167375A (en) * 1990-10-30 1992-06-15 Toyo Takasago Kandenchi Kk Rectangular lithium secondary cell
JP2014103082A (en) * 2012-11-22 2014-06-05 Denso Corp Power storage element and manufacturing method thereof

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