JP2021111538A - Secondary battery and manufacturing method of secondary battery - Google Patents

Secondary battery and manufacturing method of secondary battery Download PDF

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JP2021111538A
JP2021111538A JP2020003347A JP2020003347A JP2021111538A JP 2021111538 A JP2021111538 A JP 2021111538A JP 2020003347 A JP2020003347 A JP 2020003347A JP 2020003347 A JP2020003347 A JP 2020003347A JP 2021111538 A JP2021111538 A JP 2021111538A
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positive electrode
negative electrode
current collector
electrode plate
electrode current
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JP7369351B2 (en
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祐輝 松田
Yuki Matsuda
祐輝 松田
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Toyota Boshoku 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
    • 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 secondary battery that suppresses the occurrence of a short circuit.SOLUTION: A secondary battery 10 comprises an electrode laminate 17 formed by laminating positive electrode plates 20 having a positive current collector 21 and negative electrode plates 30 having a negative current collector 31 via a separator 40. The positive current collector 21 has a burr 23 that protrudes toward one side of a thickness direction on at least a part of a peripheral edge 22. The negative current collector 31 has a burr 23 that protrudes toward one side of the thickness direction on at least a part of a peripheral edge 32. The positive electrode plates 20 and the negative electrode plates 30 are laminated such that the protruding direction of the burr 23 of the positive current collector 21 and the protruding direction of the burr 33 of the negative current collector 31 are the same direction, and at least a part of a peripheral edge 22 of the positive current collector 21 and at least a part of the peripheral edge 32 of the negative current collector 31 are overlapping in a laminate direction.SELECTED DRAWING: Figure 4

Description

本開示は、二次電池及び二次電池の製造方法に関する。 The present disclosure relates to a secondary battery and a method for manufacturing the secondary battery.

特許文献１には、正極および負極が交互に積層された積層体を備えた積層型二次電池が開示されている。そして、正極の縁部および負極の縁部に押圧力が加わらないように構成することにより、正極および負極の形成工程（切断工程）において、正極および負極の切断面にバリ突起が発生している場合でも、このバリ突起によって正極と負極とが短絡するのを抑制することができる、と記載されている。 Patent Document 1 discloses a laminated secondary battery including a laminated body in which positive electrodes and negative electrodes are alternately laminated. Then, by configuring the edge of the positive electrode and the edge of the negative electrode so that no pressing force is applied, burr protrusions are generated on the cut surfaces of the positive electrode and the negative electrode in the process of forming the positive electrode and the negative electrode (cutting step). Even in this case, it is stated that the burr projection can prevent the positive electrode and the negative electrode from being short-circuited.

特許文献２には、負極電極層、負極活物質層、固体電解質層、正極活物質層、正極電極層を１単位として構成される全固体電池が開示されている。この全固体電池は、電池外周端部の欠損や電極バリ等による短絡を防止するために、各層の間に絶縁部材が配設された構造を有している。 Patent Document 2 discloses an all-solid-state battery composed of a negative electrode layer, a negative electrode active material layer, a solid electrolyte layer, a positive electrode active material layer, and a positive electrode layer as one unit. This all-solid-state battery has a structure in which an insulating member is arranged between each layer in order to prevent a short circuit due to a chipping at the outer peripheral end of the battery or an electrode burr or the like.

特開２０１１−２２２３８８号公報Japanese Unexamined Patent Publication No. 2011-222388 特開２０１４−１３０７５４号公報Japanese Unexamined Patent Publication No. 2014-130754

特許文献１及び特許文献２に記載の構成では、正極板及び負極板におけるバリに起因した短絡を十分に抑制することができず、問題がある。 The configurations described in Patent Document 1 and Patent Document 2 have a problem because short circuits caused by burrs on the positive electrode plate and the negative electrode plate cannot be sufficiently suppressed.

本開示は、短絡が抑制された二次電池を提供すること、また、そのような二次電池の製造方法を提供することを目的としている。 It is an object of the present disclosure to provide a secondary battery in which a short circuit is suppressed, and to provide a method for manufacturing such a secondary battery.

本開示の二次電池は、正極集電体を有する正極板と、負極集電体を有する負極板とがセパレータを介して積層されてなる電極積層体を備えた二次電池であって、前記正極集電体は、周端縁の少なくとも一部に、厚さ方向における一方側に向かって突出するバリを有し、前記負極集電体は、周端縁の少なくとも一部に、厚さ方向における一方側に向かって突出するバリを有し、前記正極板及び前記負極板は、前記正極集電体のバリの突出方向と前記負極集電体のバリの突出方向を同じ方向とし、前記正極集電体の周端縁と前記負極集電体の周端縁の少なくとも一部が積層方向に重なる形態で積層されている。 The secondary battery of the present disclosure is a secondary battery including an electrode laminate in which a positive electrode plate having a positive electrode current collector and a negative electrode plate having a negative electrode current collector are laminated via a separator. The positive electrode current collector has burrs protruding toward one side in the thickness direction at least a part of the peripheral edge, and the negative electrode current collector has a thickness direction at least a part of the peripheral edge. The positive electrode plate and the negative electrode plate have burrs protruding toward one side of the above electrode, and the positive electrode current collector has burrs protruding in the same direction as the negative electrode current collector burrs. At least a part of the peripheral edge of the current collector and the peripheral edge of the negative electrode current collector are laminated in a stacking direction.

本開示の二次電池の製造方法は、正極集電体を有する正極板と、負極集電体を有する負極板とがセパレータを介して積層されてなる電極積層体を備えた二次電池の製造方法であって、前記正極集電体の材料である正極用金属箔に正極活物質が塗布された母材を打ち抜いて、前記正極板を得る工程と、前記正極集電体の材料である負極用金属箔に負極活物質が塗布された母材を打ち抜いて、前記負極板を得る工程と、前記正極板が打ち抜かれた方向と前記負極板が打ち抜かれた方向を同じ方向とし、前記正極集電体の周端縁と前記負極集電体の周端縁の少なくとも一部が積層方向に重なる形態で前記正極板及び前記負極板を積層する工程と、を含む。 The method for manufacturing a secondary battery of the present disclosure is to manufacture a secondary battery including an electrode laminate in which a positive electrode plate having a positive electrode current collector and a negative electrode plate having a negative electrode current collector are laminated via a separator. The method is a step of punching a base material in which a positive electrode active material is applied to a metal foil for a positive electrode, which is a material of the positive electrode current collector, to obtain the positive electrode plate, and a negative electrode, which is a material of the positive electrode current collector. The step of punching out the base material coated with the negative electrode active material on the metal foil to obtain the negative electrode plate and the direction in which the positive electrode plate is punched and the direction in which the negative electrode plate is punched are set to be the same direction, and the positive electrode collection is performed. The step of laminating the positive electrode plate and the negative electrode plate in a form in which at least a part of the peripheral edge of the electric body and the peripheral edge of the negative electrode current collector overlap in the stacking direction is included.

本開示によれば、短絡が抑制された二次電池を提供できる。また、そのような二次電池の製造方法を提供できる。 According to the present disclosure, it is possible to provide a secondary battery in which a short circuit is suppressed. Further, it is possible to provide a method for manufacturing such a secondary battery.

一実施形態における二次電池の斜視図である。It is a perspective view of the secondary battery in one Embodiment. 外装体及びセパレータを省略して、正極板及び負極板を表す平面図である。It is a top view which shows the positive electrode plate and the negative electrode plate by omitting an exterior body and a separator. 図２のＩＩＩ−ＩＩＩ断面に対応する断面図である。It is sectional drawing corresponding to the section III-III of FIG. 図２のＩＶ−ＩＶ断面に対応する断面図である。It is sectional drawing corresponding to the IV-IV cross section of FIG. 正極板を得る工程を説明するための説明図である。It is explanatory drawing for demonstrating the process of obtaining a positive electrode plate. 正極板及び負極板を積層する工程を説明するための説明図である。It is explanatory drawing for demonstrating the process of laminating the positive electrode plate and the negative electrode plate. 正極タブ部を正極端子に溶接する工程を説明するための説明図である。It is explanatory drawing for demonstrating the process of welding a positive electrode tab portion to a positive electrode terminal.

＜実施形態１＞
図１に示すように、二次電池１０は、例えばリチウムイオン電池などによって構成され、矩形状をなす可撓性を有した外装体１２と、外装体１２内に封止された電極積層体１７及び電解液（図示略）と、外装体１２から露出する正極端子１４及び負極端子１５とを備えている。外装体１２は、例えばアルミニウムを用いた一対の矩形状をなす可撓性のラミネートフィルムの周縁部同士を溶着することによって形成される。 <Embodiment 1>
As shown in FIG. 1, the secondary battery 10 is composed of, for example, a lithium ion battery or the like, and has a rectangular flexible outer body 12 and an electrode laminate 17 sealed in the outer body 12. And an electrolytic solution (not shown), and a positive electrode terminal 14 and a negative electrode terminal 15 exposed from the exterior body 12. The exterior body 12 is formed by welding the peripheral edges of a pair of rectangular flexible laminate films made of aluminum, for example.

図２及び図３に示すように、電極積層体１７は、矩形状の正極板２０と、正極板２０よりも一回り大きい矩形状の負極板３０とを、山折りと谷折りを交互に繰り返すつづら折りされた帯状のセパレータ４０を介して交互に複数積層することによって形成される。この場合、セパレータ４０の一方側の対向する面同士の間に正極板２０がそれぞれ挟まれ、他方側の対向する面同士の間に負極板３０がそれぞれ挟まれた状態になっている。 As shown in FIGS. 2 and 3, the electrode laminate 17 alternately repeats mountain folds and valley folds of a rectangular positive electrode plate 20 and a rectangular negative electrode plate 30 that is one size larger than the positive electrode plate 20. It is formed by alternately stacking a plurality of strip-shaped separators 40 which are folded in a zigzag manner. In this case, the positive electrode plates 20 are sandwiched between the opposing surfaces on one side of the separator 40, and the negative electrode plates 30 are sandwiched between the opposing surfaces on the other side.

セパレータ４０は、例えば絶縁性を有する合成樹脂製の不織布によって構成される。セパレータ４０における隣り合う２つの折り目間の矩形板状の部分は、負極板３０よりも一回り大きくなっている。つまり、図３に示すように、二次電池１０において、正極板２０、負極板３０、及びセパレータ４０の大きさを比較すると、セパレータ４０が最も大きく、正極板２０が最も小さい。 The separator 40 is made of, for example, a non-woven fabric made of a synthetic resin having an insulating property. The rectangular plate-shaped portion between the two adjacent folds in the separator 40 is one size larger than the negative electrode plate 30. That is, as shown in FIG. 3, when the sizes of the positive electrode plate 20, the negative electrode plate 30, and the separator 40 are compared in the secondary battery 10, the separator 40 is the largest and the positive electrode plate 20 is the smallest.

図４に示すように、正極板２０は、正極集電体２１と、正極集電体２１の両面に塗布された正極活物質２５とを有している。正極集電体２１は、例えば厚さが１０μｍ〜２０μｍのアルミニウム箔（正極用金属箔）２１Ａなどの導電性材料によって構成される。正極活物質２５は、例えばリチウムイオンなどの陽イオンを吸蔵及び放出可能な材料によって構成される。 As shown in FIG. 4, the positive electrode plate 20 has a positive electrode current collector 21 and a positive electrode active material 25 coated on both sides of the positive electrode current collector 21. The positive electrode current collector 21 is made of a conductive material such as an aluminum foil (metal foil for positive electrode) 21A having a thickness of 10 μm to 20 μm. The positive electrode active material 25 is made of a material capable of occluding and releasing cations such as lithium ions.

正極集電体２１は、周端縁２２の少なくとも一部に、厚さ方向における一方側に向かって突出するバリ２３を有している。バリ２３は、後述する正極板２０を得る工程において、アルミニウム箔２１Ａが打ち抜かれる方向に沿って延びる形態で形成される。バリ２３は、アルミニウム箔２１Ａの延性に起因して周端縁２２に沿って形成され、例えば、先端に向かうにつれて先細る鋸歯状をなしている。正極集電体２１は、厚さ方向においてバリ２３とは反対側の縁部に、いわゆるだれと呼ばれるＲ面を有している。つまり、バリ２３は、正極集電体２１の厚さ方向における一方側に向かって突出する一方、他方側に突出しない構成となっている。 The positive electrode current collector 21 has a burr 23 protruding toward one side in the thickness direction at least a part of the peripheral edge 22. The burr 23 is formed in a form in which the aluminum foil 21A extends along the punching direction in the step of obtaining the positive electrode plate 20 described later. The burr 23 is formed along the peripheral edge 22 due to the ductility of the aluminum foil 21A, and has a serrated shape that tapers toward the tip, for example. The positive electrode current collector 21 has an R surface called a so-called who on the edge opposite to the burr 23 in the thickness direction. That is, the burr 23 has a configuration in which the positive electrode current collector 21 projects toward one side in the thickness direction, but does not project toward the other side.

正極集電体２１は、図２に示すように、略矩形板状をなしており、その長手方向の一辺側の端部に矩形板状の正極タブ部（正極集電部）２７が突出するように形成されている。すなわち、正極タブ部２７は、正極集電体２１と一体形成されており、セパレータ４０から露出するように突出している。各正極タブ部２７は、正極端子１４に電気的に接続される。正極タブ部２７には、正極活物質２５が塗布されていない。 As shown in FIG. 2, the positive electrode current collector 21 has a substantially rectangular plate shape, and a rectangular plate-shaped positive electrode tab portion (positive electrode current collector) 27 projects from one end on one side in the longitudinal direction thereof. It is formed like this. That is, the positive electrode tab portion 27 is integrally formed with the positive electrode current collector 21, and projects so as to be exposed from the separator 40. Each positive electrode tab portion 27 is electrically connected to the positive electrode terminal 14. The positive electrode active material 25 is not applied to the positive electrode tab portion 27.

正極タブ部２７は、正極集電体２１の周端縁２２を一部切り欠いた切り欠き部２８を有している。切り欠き部２８は、正極板２０を二等分する中心線ＣＬに対して、正極板２０が非対称となるように形成されている。この中心線ＣＬは、略矩形板状をなす正極集電体２１において互いに対向する２辺の中間をとおる線であり、正極タブ部２７の突出方向に沿って直線状に延びている。切り欠き部２８は、正極タブ部２７の突出方向に沿って延びたスリット状をなし、正極タブ部２７に設けられている。中心線ＣＬが延びる方向について、切り欠き部２８の長さは、後述する第１溶接部２９Ａ及び第２溶接部２９Ｂの長さよりも大きい。切り欠き部２８は、中心線ＣＬの両側に第１溶接部２９Ａと第２溶接部２９Ｂをそれぞれ形成するスペースを残して、中心線ＣＬから離れる方向にオフセットして設けられている。 The positive electrode tab portion 27 has a notched portion 28 in which the peripheral edge 22 of the positive electrode current collector 21 is partially cut out. The cutout portion 28 is formed so that the positive electrode plate 20 is asymmetric with respect to the center line CL that bisects the positive electrode plate 20. The center line CL is a line passing through the middle of two opposite sides of the positive electrode current collector 21 forming a substantially rectangular plate shape, and extends linearly along the protruding direction of the positive electrode tab portion 27. The cutout portion 28 has a slit shape extending along the protruding direction of the positive electrode tab portion 27, and is provided in the positive electrode tab portion 27. In the direction in which the center line CL extends, the length of the cutout portion 28 is larger than the length of the first welded portion 29A and the second welded portion 29B, which will be described later. The cutout portion 28 is provided offset in the direction away from the center line CL, leaving a space for forming the first welded portion 29A and the second welded portion 29B on both sides of the center line CL.

複数の正極板２０は、複数の正極タブ部２７を積層方向に束ねた状態で切り欠き部２８の両側において正極端子１４に溶接されている。換言すれば、正極タブ部２７は、切り欠き部２８の両側に、正極端子１４に溶接された第１溶接部２９Ａ及び第２溶接部２９Ｂを有している。第１溶接部２９Ａ及び第２溶接部２９Ｂは、正極集電体２１と正極端子１４を物理的に固定するとともに電気的に接続する。本実施形態では、複数の正極板２０が、複数の溶接部２９Ａ，２９Ｂを介して正極端子１４に接続されることで、二次電池１０の高出力化に適した構成となっている。 The plurality of positive electrode plates 20 are welded to the positive electrode terminals 14 on both sides of the cutout portions 28 in a state where the plurality of positive electrode tab portions 27 are bundled in the stacking direction. In other words, the positive electrode tab portion 27 has a first welded portion 29A and a second welded portion 29B welded to the positive electrode terminal 14 on both sides of the notch portion 28. The first welded portion 29A and the second welded portion 29B physically fix the positive electrode current collector 21 and the positive electrode terminal 14 and electrically connect them. In the present embodiment, the plurality of positive electrode plates 20 are connected to the positive electrode terminals 14 via the plurality of welded portions 29A and 29B, so that the configuration is suitable for increasing the output of the secondary battery 10.

図４に示すように、負極板３０は、負極集電体３１と、負極集電体３１の両面に塗布された負極活物質３５とを有している。負極集電体３１は、例えば厚さが１０μｍ〜２０μｍの銅箔（負極用金属箔）などの導電性材料によって構成される。負極活物質３５は、例えばリチウムイオンなどの陽イオンを吸蔵及び放出可能な材料によって構成される。 As shown in FIG. 4, the negative electrode plate 30 has a negative electrode current collector 31 and a negative electrode active material 35 coated on both sides of the negative electrode current collector 31. The negative electrode current collector 31 is made of a conductive material such as a copper foil (metal foil for a negative electrode) having a thickness of 10 μm to 20 μm. The negative electrode active material 35 is made of a material capable of occluding and releasing cations such as lithium ions.

負極集電体３１は、周端縁３２の少なくとも一部に、厚さ方向における一方側に向かって突出するバリ３３を有している。バリ３３は、後述する負極板３０を得る工程において、銅箔が打ち抜かれる方向に沿って延びる形態で形成される。バリ３３は、銅箔の延性に起因して周端縁３２に沿って形成され、例えば、先端に向かうにつれて先細る鋸歯状をなしている。銅箔は、アルミニウム箔２１Ａに比して延性が大きく、バリ３３の突出高さがバリ２３の突出高さよりも大きくなる傾向にある。負極集電体３１は、厚さ方向においてバリ３３とは反対側の縁部に、いわゆるだれと呼ばれるＲ面を有している。つまり、バリ３３は、負極集電体３１の厚さ方向における一方側に向かって突出する一方、他方側に突出しない構成となっている。 The negative electrode current collector 31 has a burr 33 protruding toward one side in the thickness direction at least a part of the peripheral edge 32. The burr 33 is formed in a form extending along the direction in which the copper foil is punched in the step of obtaining the negative electrode plate 30, which will be described later. The burr 33 is formed along the peripheral edge 32 due to the ductility of the copper foil, and has, for example, a serrated shape that tapers toward the tip. The copper foil has a larger ductility than the aluminum foil 21A, and the protruding height of the burr 33 tends to be larger than the protruding height of the burr 23. The negative electrode current collector 31 has an R surface called a so-called who on the edge opposite to the burr 33 in the thickness direction. That is, the burr 33 has a configuration in which the negative electrode current collector 31 projects toward one side in the thickness direction, but does not project toward the other side.

負極集電体３１は、図２に示すように、略矩形板状をなしており、その長手方向の一辺側の端部に矩形板状の負極タブ部（負極集電部）３７が突出するように形成されている。すなわち、負極タブ部３７は、負極集電体３１と一体形成されており、セパレータ４０から露出するように突出している。各負極タブ部３７は、負極端子１５に電気的に接続される。負極タブ部３７には、負極活物質３５が塗布されていない。 As shown in FIG. 2, the negative electrode current collector 31 has a substantially rectangular plate shape, and a rectangular plate-shaped negative electrode tab portion (negative electrode current collector) 37 projects from one end on one side in the longitudinal direction thereof. It is formed like this. That is, the negative electrode tab portion 37 is integrally formed with the negative electrode current collector 31, and projects so as to be exposed from the separator 40. Each negative electrode tab portion 37 is electrically connected to the negative electrode terminal 15. The negative electrode active material 35 is not applied to the negative electrode tab portion 37.

負極タブ部３７は、負極集電体３１の周端縁３２を一部切り欠いた切り欠き部３８を有している。切り欠き部３８は、負極板３０を二等分する中心線ＣＬに対して、負極板３０が非対称となるように形成されている。この中心線ＣＬは、略矩形板状をなす負極集電体３１において互いに対向する２辺の中間をとおる線であり、負極タブ部３７の突出方向に沿って直線状に延びている。切り欠き部３８は、負極タブ部３７の突出方向に沿って延びたスリット状をなし、負極タブ部３７に設けられている。中心線ＣＬが延びる方向について、切り欠き部３８の長さは、後述する第１溶接部３９Ａ及び第２溶接部３９Ｂの長さよりも大きい。切り欠き部３８は、中心線ＣＬの両側に第１溶接部３９Ａと第２溶接部３９Ｂをそれぞれ形成するスペースを残して、中心線ＣＬから離れる方向にオフセットして設けられている。 The negative electrode tab portion 37 has a notched portion 38 in which the peripheral edge 32 of the negative electrode current collector 31 is partially cut out. The cutout portion 38 is formed so that the negative electrode plate 30 is asymmetric with respect to the center line CL that bisects the negative electrode plate 30. The center line CL is a line passing through the middle of two opposite sides of the negative electrode current collector 31 forming a substantially rectangular plate shape, and extends linearly along the protruding direction of the negative electrode tab portion 37. The cutout portion 38 has a slit shape extending along the protruding direction of the negative electrode tab portion 37, and is provided in the negative electrode tab portion 37. In the direction in which the center line CL extends, the length of the cutout portion 38 is larger than the length of the first welded portion 39A and the second welded portion 39B, which will be described later. The cutout portion 38 is provided offset in the direction away from the center line CL, leaving a space for forming the first welded portion 39A and the second welded portion 39B on both sides of the center line CL.

複数の負極板３０は、複数の負極タブ部３７を積層方向に束ねた状態で切り欠き部３８の両側において負極端子１５に溶接されている。換言すれば、負極タブ部３７は、切り欠き部３８の両側に、負極端子１５に溶接された第１溶接部３９Ａ及び第２溶接部３９Ｂを有している。第１溶接部３９Ａ及び第２溶接部３９Ｂは、負極集電体３１と負極端子１５を物理的に固定するとともに電気的に接続する。本実施形態では、複数の負極板３０が、複数の溶接部３９Ａ，３９Ｂを介して負極端子１５に接続されることで、二次電池１０の高出力化に適した構成となっている。 The plurality of negative electrode plates 30 are welded to the negative electrode terminals 15 on both sides of the notch 38 in a state where the plurality of negative electrode tab portions 37 are bundled in the stacking direction. In other words, the negative electrode tab portion 37 has a first welded portion 39A and a second welded portion 39B welded to the negative electrode terminal 15 on both sides of the notch portion 38. The first welded portion 39A and the second welded portion 39B physically fix the negative electrode current collector 31 and the negative electrode terminal 15 and electrically connect them. In the present embodiment, the plurality of negative electrode plates 30 are connected to the negative electrode terminals 15 via the plurality of welded portions 39A and 39B, so that the configuration is suitable for increasing the output of the secondary battery 10.

正極板２０及び負極板３０は、正極集電体２１の周端縁２２と負極集電体３１の周端縁３２の少なくとも一部が積層方向に重なる形態で積層されている。正極集電体２１の周端縁２２と負極集電体３１の周端縁３２の少なくとも一部が積層方向に重なる形態としては、図２に示すように、積層方向から見て正極集電体２１の周端縁２２と負極集電体３１の周端縁３２が交差して配置される構成を例示できる。正極板２０及び負極板３０は、正極タブ部２７及び負極タブ部３７が互いに反対方向に突出する構成上、周端縁２２と周端縁３２が積層方向から見て交差して配置される部分を有する。また、正極板２０及び負極板３０は、積層方向から見て負極板３０の周端縁３２に対して正極板２０の周端縁２２が傾いて配置される場合にも、傾斜角度に応じて周端縁２２と周端縁３２が積層方向から見て交差して配置され得る。その他にも、正極集電体２１の周端縁２２と負極集電体３１の周端縁３２の少なくとも一部が積層方向に重なる形態としては、正極集電体２１の周端縁２２と負極集電体３１の周端縁３２の一部が積層方向と直交する方向に平行に延びた構成であってもよい。 The positive electrode plate 20 and the negative electrode plate 30 are laminated so that at least a part of the peripheral edge 22 of the positive electrode current collector 21 and the peripheral edge 32 of the negative electrode current collector 31 overlap in the stacking direction. As shown in FIG. 2, as shown in FIG. 2, the positive electrode current collector has a form in which at least a part of the peripheral edge 22 of the positive electrode current collector 21 and the peripheral edge 32 of the negative electrode current collector 31 overlap in the stacking direction. It is possible to exemplify a configuration in which the peripheral edge 22 of 21 and the peripheral edge 32 of the negative electrode current collector 31 are arranged so as to intersect with each other. The positive electrode plate 20 and the negative electrode plate 30 are formed so that the positive electrode tab portion 27 and the negative electrode tab portion 37 project in opposite directions, so that the peripheral edge 22 and the peripheral edge 32 are arranged so as to intersect each other when viewed from the stacking direction. Has. Further, when the positive electrode plate 20 and the negative electrode plate 30 are arranged so that the peripheral edge 22 of the positive electrode plate 20 is tilted with respect to the peripheral edge 32 of the negative electrode plate 30 when viewed from the stacking direction, the positive electrode plate 20 and the negative electrode plate 30 are arranged according to the inclination angle. The peripheral edge 22 and the peripheral edge 32 may be arranged so as to intersect each other when viewed from the stacking direction. In addition, as a form in which at least a part of the peripheral edge 22 of the positive electrode current collector 21 and the peripheral edge 32 of the negative electrode current collector 31 overlap in the stacking direction, the peripheral edge 22 of the positive electrode current collector 21 and the negative electrode A part of the peripheral edge 32 of the current collector 31 may extend parallel to the direction orthogonal to the stacking direction.

正極板２０及び負極板３０は、図４に示すように、正極集電体２１のバリ２３の突出方向と負極集電体３１のバリ３３の突出方向を同じ方向として積層されている。図４では、セパレータ４０の第１部分４１、正極板２０、セパレータ４０の第２部分４２、負極板３０、セパレータ４０の第３部分４３が上からこの順に積層されている。正極集電体２１のバリ２３は図４の下方に向けて突出し、セパレータ４０の第２部分４２に一部陥入する。負極集電体３１のバリ３３は図４の下方に向けて突出し、セパレータ４０の第３部分４３に一部陥入する。つまり、セパレータ４０において正極板２０と負極板３０の間に介在する部分４１，４２，４３には、正極集電体２１のバリ２３と負極集電体３１のバリ３３の一方のみが陥入し、他方が陥入しない。正極板２０及び負極板３０は、正極集電体２１の周端縁２２と負極集電体３１の周端縁３２が積層方向に重なる位置において、セパレータ４０の表裏両側からバリ２３，３３が陥入しない構成となっている。セパレータ４０の厚さは特に限定しないが、例えば、正極集電体２１のバリ２３及び負極集電体３１のバリ３３について想定される最大突出量、本実施形態では、負極集電体３１のバリ３３における最大突出量より厚いことが好ましい。このような構成によれば、正極集電体２１のバリ２３及び負極集電体３１のバリ３３による二次電池１０の短絡をより一層抑制できる。 As shown in FIG. 4, the positive electrode plate 20 and the negative electrode plate 30 are laminated so that the protruding direction of the burr 23 of the positive electrode current collector 21 and the protruding direction of the burr 33 of the negative electrode current collector 31 are the same direction. In FIG. 4, the first portion 41 of the separator 40, the positive electrode plate 20, the second portion 42 of the separator 40, the negative electrode plate 30, and the third portion 43 of the separator 40 are laminated in this order from the top. The burr 23 of the positive electrode current collector 21 projects downward in FIG. 4 and partially enters the second portion 42 of the separator 40. The burr 33 of the negative electrode current collector 31 projects downward in FIG. 4 and partially enters the third portion 43 of the separator 40. That is, only one of the burrs 23 of the positive electrode current collector 21 and the burrs 33 of the negative electrode current collector 31 is embedded in the portions 41, 42, and 43 of the separator 40 that are interposed between the positive electrode plate 20 and the negative electrode plate 30. , The other does not invade. In the positive electrode plate 20 and the negative electrode plate 30, burrs 23 and 33 fall from both the front and back sides of the separator 40 at a position where the peripheral edge 22 of the positive electrode current collector 21 and the peripheral edge 32 of the negative electrode current collector 31 overlap in the stacking direction. It is configured not to enter. The thickness of the separator 40 is not particularly limited, but for example, the maximum protrusion amount assumed for the burr 23 of the positive electrode current collector 21 and the burr 33 of the negative electrode current collector 31, the burr of the negative electrode current collector 31 in the present embodiment. It is preferably thicker than the maximum protrusion amount at 33. According to such a configuration, the short circuit of the secondary battery 10 due to the burr 23 of the positive electrode current collector 21 and the burr 33 of the negative electrode current collector 31 can be further suppressed.

次に、二次電池１０の製造方法について説明する。二次電池１０の製造方法は、正極板２０を得る工程と、負極板３０を得る工程と、正極板２０及び負極板３０を積層する工程と、正極タブ部２７を正極端子１４に溶接する工程と、負極タブ部３７を負極端子１５に溶接する工程と、を含んでいる。二次電池１０の製造方法は、他の任意の工程を有していてもよいが、正極集電体２１のバリ２３を取り除く工程、及び負極集電体３１のバリ３３を取り除く工程、を含んでいなくてもよい。二次電池１０の製造方法は、このようなバリ２３，３３を取り除く工程を含まないから、工数低減に寄与することができる。 Next, a method of manufacturing the secondary battery 10 will be described. The method for manufacturing the secondary battery 10 includes a step of obtaining the positive electrode plate 20, a step of obtaining the negative electrode plate 30, a step of laminating the positive electrode plate 20 and the negative electrode plate 30, and a step of welding the positive electrode tab portion 27 to the positive electrode terminal 14. And a step of welding the negative electrode tab portion 37 to the negative electrode terminal 15. The method for manufacturing the secondary battery 10 may have any other steps, but includes a step of removing the burr 23 of the positive electrode current collector 21 and a step of removing the burr 33 of the negative electrode current collector 31. You don't have to. Since the method for manufacturing the secondary battery 10 does not include such a step of removing the burrs 23 and 33, it can contribute to the reduction of man-hours.

正極板２０を得る工程では、アルミニウム箔２１Ａに正極活物質２５が塗布された母材２０Ａを打ち抜いて、正極板２０を得る。正極板２０を得る工程は、例えば正極板２０の外形と同じ形状の打ち抜き刃を有するプレス機を用いて行うことができる。図５に示すように、母材２０Ａは、帯状のアルミニウム箔２１Ａの両面に所定間隔で正極活物質２５が塗布されてなる。正極板２０を得る工程では、母材２０Ａにおいて正極活物質２５が塗布された領域と塗布されていない領域に跨って打ち抜き刃を当てて、打ち抜き加工をすることで正極板２０を形成する。この過程で、正極集電体２１には、周端縁２２の少なくとも一部に、打ち抜き方向に沿って突出するバリ２３が形成される。正極板２０の打ち抜かれた方向は、正極板２０において、打ち抜き刃が最初に当たった位置から打ち抜き刃が抜けた位置に向かう方向として規定できる。 In the step of obtaining the positive electrode plate 20, the base metal 20A coated with the positive electrode active material 25 on the aluminum foil 21A is punched out to obtain the positive electrode plate 20. The step of obtaining the positive electrode plate 20 can be performed, for example, by using a press machine having a punching blade having the same shape as the outer shape of the positive electrode plate 20. As shown in FIG. 5, the base metal 20A is formed by applying the positive electrode active material 25 to both surfaces of the strip-shaped aluminum foil 21A at predetermined intervals. In the step of obtaining the positive electrode plate 20, the positive electrode plate 20 is formed by applying a punching blade across the region where the positive electrode active material 25 is applied and the region where the positive electrode active material 25 is not applied in the base material 20A and punching. In this process, the positive electrode current collector 21 is formed with burrs 23 protruding along the punching direction at least a part of the peripheral edge 22. The punched direction of the positive electrode plate 20 can be defined as a direction from the position where the punching blade first hits to the position where the punching blade is pulled out in the positive electrode plate 20.

負極板３０を得る工程では、銅箔に負極活物質３５が塗布された母材を打ち抜いて、負極板３０を得る。負極板３０を得る工程は、例えば負極板３０の外形と同じ形状の打ち抜き刃を有するプレス機を用いて行うことができる。母材は、帯状の銅箔の両面に所定間隔で負極活物質３５が塗布されてなる。負極板３０を得る工程では、母材における負極活物質３５が塗布された領域と塗布されていない領域に跨って打ち抜き刃を当てて、打ち抜き加工をすることで負極板３０を形成する。この過程で、負極集電体３１には、周端縁３２の少なくとも一部に、打ち抜き方向に沿って突出するバリ３３が形成される。負極板３０の打ち抜かれた方向は、負極板３０において、打ち抜き刃が最初に当たった位置から打ち抜き刃が抜けた位置に向かう方向として規定できる。 In the step of obtaining the negative electrode plate 30, the base metal coated with the negative electrode active material 35 on the copper foil is punched out to obtain the negative electrode plate 30. The step of obtaining the negative electrode plate 30 can be performed, for example, by using a press machine having a punching blade having the same shape as the outer shape of the negative electrode plate 30. The base material is formed by applying the negative electrode active material 35 on both sides of the strip-shaped copper foil at predetermined intervals. In the step of obtaining the negative electrode plate 30, the negative electrode plate 30 is formed by applying a punching blade across a region in which the negative electrode active material 35 is applied and a region in which the negative electrode active material 35 is not applied in the base material and punching. In this process, the negative electrode current collector 31 is formed with burrs 33 protruding along the punching direction at least a part of the peripheral edge 32. The punched direction of the negative electrode plate 30 can be defined as a direction from the position where the punching blade first hits to the position where the punching blade is pulled out in the negative electrode plate 30.

正極板２０及び負極板３０を積層する工程では、正極板２０が打ち抜かれた方向と負極板３０が打ち抜かれた方向を同じ方向とし、正極集電体２１の周端縁２２と負極集電体３１の周端縁３２の少なくとも一部が積層方向に重なる形態で正極板２０及び負極板３０を積層する。換言すれば、正極板２０及び負極板３０を積層する工程では、正極板２０を得る工程において、打ち抜き刃が当てられた側の面と、負極板３０を得る工程において、打ち抜き刃が当てられた側の負極板３０の面とは反対側の面とを、セパレータ４０を介して対向させるとともに、正極集電体２１の周端縁２２と、負極集電体３１の周端縁３２の少なくとも一部が重なるように正極板２０及び負極板３０を積層する。図６に示すように、正極板２０及び負極板３０を積層する工程では、正極板２０と負極板３０を交互に積層しつつセパレータ４０をつづら折りして、正極板２０と負極板３０の間にセパレータ４０を介在させる。この際、正極板２０及び負極板３０の切り欠き部２８，３８の位置を目安にして、正極板２０及び負極板３０が正規の向きから、表裏反転していないことを確認できる。正極板２０及び負極板３０の正規の向きは、正極板２０が打ち抜かれた方向と負極板３０が打ち抜かれた方向を同じ方向とした向きであり、すなわち、正極集電体２１のバリ２３の突出方向と負極集電体３１のバリ３３の突出方向を同じ方向とした向きである。 In the step of laminating the positive electrode plate 20 and the negative electrode plate 30, the direction in which the positive electrode plate 20 is punched and the direction in which the negative electrode plate 30 is punched are the same, and the peripheral edge 22 of the positive electrode current collector 21 and the negative electrode current collector are aligned. The positive electrode plate 20 and the negative electrode plate 30 are laminated so that at least a part of the peripheral edge 32 of 31 overlaps in the stacking direction. In other words, in the step of laminating the positive electrode plate 20 and the negative electrode plate 30, the surface on the side to which the punching blade was applied in the step of obtaining the positive electrode plate 20 and the punching blade were applied in the step of obtaining the negative electrode plate 30. The surface of the negative electrode plate 30 on the side opposite to the surface of the negative electrode plate 30 is opposed to each other via the separator 40, and at least one of the peripheral edge 22 of the positive electrode current collector 21 and the peripheral edge 32 of the negative electrode current collector 31. The positive electrode plate 20 and the negative electrode plate 30 are laminated so that the portions overlap. As shown in FIG. 6, in the step of laminating the positive electrode plate 20 and the negative electrode plate 30, the separator 40 is folded in a zigzag manner while alternately laminating the positive electrode plate 20 and the negative electrode plate 30, and between the positive electrode plate 20 and the negative electrode plate 30. A separator 40 is interposed. At this time, it can be confirmed that the positive electrode plate 20 and the negative electrode plate 30 are not turned upside down from the normal orientation by using the positions of the notched portions 28 and 38 of the positive electrode plate 20 and the negative electrode plate 30 as a guide. The normal orientation of the positive electrode plate 20 and the negative electrode plate 30 is the direction in which the positive electrode plate 20 is punched out and the negative electrode plate 30 is punched out in the same direction, that is, the burr 23 of the positive electrode current collector 21. The protruding direction and the protruding direction of the burr 33 of the negative electrode current collector 31 are the same direction.

正極タブ部２７を正極端子１４に溶接する工程では、複数の正極タブ部２７を積層方向に束ねた状態で切り欠き部２８の両側において正極端子１４に溶接する。図６に示すように、まず、複数の正極タブ部２７において切り欠き部２８の一方側に位置する部分に超音波振動が印加されたホーン５０を押圧し、第１溶接部２９Ａを形成する。次に、複数の正極タブ部２７において切り欠き部２８の他方側に位置する部分に超音波振動が印加されたホーン５０を押圧し、第２溶接部２９Ｂを形成する。この際、第１溶接部２９Ａと第２溶接部２９Ｂの間には、切り欠き部２８が介在するから、第２溶接部２９Ｂを形成する際の超音波振動や熱が第１溶接部２９Ａに及びにくくなっている。第１溶接部２９Ａを形成する前に、切り欠き部２８に位置決め用のピンを挿通させて、複数の正極タブ部２７の位置を互いに整合させてもよい。例えば、複数の正極板２０のうち1つの正極板２０が正規の向きから表裏反転した場合には、反転した正極板２０の正極タブ部２７が位置決め用のピンと干渉することで、複数の正極タブ部２７を溶接する前に正極板２０の表裏反転を容易に検出できる。 In the step of welding the positive electrode tab portion 27 to the positive electrode terminal 14, the positive electrode tab portions 27 are welded to the positive electrode terminals 14 on both sides of the notch portion 28 in a state of being bundled in the stacking direction. As shown in FIG. 6, first, the horn 50 to which ultrasonic vibration is applied is pressed against a portion of the plurality of positive electrode tab portions 27 located on one side of the notch portion 28 to form the first welded portion 29A. Next, the horn 50 to which ultrasonic vibration is applied is pressed against the portion of the plurality of positive electrode tab portions 27 located on the other side of the notch portion 28 to form the second welded portion 29B. At this time, since the notch 28 is interposed between the first welded portion 29A and the second welded portion 29B, ultrasonic vibration and heat when forming the second welded portion 29B are applied to the first welded portion 29A. And it is getting harder. Before forming the first welded portion 29A, a positioning pin may be inserted through the notch portion 28 to align the positions of the plurality of positive electrode tab portions 27 with each other. For example, when one of the plurality of positive electrode plates 20 is inverted from the normal orientation, the positive electrode tab portion 27 of the inverted positive electrode plate 20 interferes with the positioning pin, so that the plurality of positive electrode tabs The front and back inversion of the positive electrode plate 20 can be easily detected before welding the portion 27.

負極タブ部３７を負極端子１５に溶接する工程では、複数の負極タブ部３７を積層方向に束ねた状態で切り欠き部３８の両側において負極端子１５に溶接する。具体的には、まず、複数の負極タブ部３７において切り欠き部３８の一方側に位置する部分に超音波振動が印加されたホーン５０を押圧し、第１溶接部３９Ａを形成する。次に、複数の負極タブ部３７において切り欠き部３８の他方側に位置する部分に超音波振動が印加されたホーン５０を押圧し、第２溶接部３９Ｂを形成する。この際、第１溶接部３９Ａと第２溶接部３９Ｂの間には、切り欠き部３８が介在するから、第２溶接部３９Ｂを形成する際の超音波振動や熱が第１溶接部３９Ａに及びにくくなっている。第１溶接部３９Ａを形成する前に、切り欠き部３８に位置決め用のピンを挿通させて、複数の負極タブ部３７の位置を互いに整合させてもよい。例えば、複数の負極板３０のうち1つの負極板３０が正規の向きから表裏反転した場合には、反転した負極板３０の負極タブ部３７が位置決め用のピンと干渉することで、複数の負極タブ部３７を溶接する前に負極板３０の表裏反転を容易に検出できる。 In the step of welding the negative electrode tab portion 37 to the negative electrode terminal 15, a plurality of negative electrode tab portions 37 are welded to the negative electrode terminals 15 on both sides of the notch portion 38 in a state of being bundled in the stacking direction. Specifically, first, the horn 50 to which ultrasonic vibration is applied is pressed against a portion of the plurality of negative electrode tab portions 37 located on one side of the notch portion 38 to form the first welded portion 39A. Next, the horn 50 to which ultrasonic vibration is applied is pressed against the portion of the plurality of negative electrode tab portions 37 located on the other side of the notch portion 38 to form the second welded portion 39B. At this time, since the notch 38 is interposed between the first welded portion 39A and the second welded portion 39B, ultrasonic vibration and heat when forming the second welded portion 39B are applied to the first welded portion 39A. And it is getting harder. Before forming the first welded portion 39A, a positioning pin may be inserted through the notch portion 38 to align the positions of the plurality of negative electrode tab portions 37 with each other. For example, when one of the plurality of negative electrode plates 30 is inverted from the normal orientation, the negative electrode tab portion 37 of the inverted negative electrode plate 30 interferes with the positioning pin, so that the plurality of negative electrode tabs The front and back inversion of the negative electrode plate 30 can be easily detected before welding the portion 37.

以上説明した実施形態によれば、次のような効果が発揮される。例えば、正極集電体の周端縁と負極集電体が積層方向に重なる部位において、正極集電体のバリの突出方向と負極集電体のバリの突出方向が互いに向かう方向である場合、正極集電体のバリと負極集電体のバリがセパレータを貫通してバリ同士が接触する可能性がある。これに対し、本実施形態の二次電池１０は、正極集電体２１のバリ２３の突出方向と負極集電体３１のバリ３３の突出方向が同じ方向であるから、正極集電体２１の周端縁２２と負極集電体３１の周端縁３２が積層方向に重なる部位においてバリ２３，３３同士が接触することを抑制できる。したがって、短絡が抑制された二次電池１０を提供できる。また、そのような二次電池１０の製造方法を提供できる。 According to the embodiment described above, the following effects are exhibited. For example, when the peripheral edge of the positive electrode current collector and the negative electrode current collector overlap in the stacking direction, the protrusion direction of the burr of the positive electrode current collector and the protrusion direction of the burr of the negative electrode current collector are in directions toward each other. The burrs of the positive electrode current collector and the burrs of the negative electrode current collector may penetrate the separator and come into contact with each other. On the other hand, in the secondary battery 10 of the present embodiment, since the protruding direction of the burr 23 of the positive electrode current collector 21 and the protruding direction of the burr 33 of the negative electrode current collector 31 are the same, the positive electrode current collector 21 It is possible to prevent the burrs 23 and 33 from coming into contact with each other at a portion where the peripheral edge 22 and the peripheral edge 32 of the negative electrode current collector 31 overlap in the stacking direction. Therefore, it is possible to provide the secondary battery 10 in which short circuits are suppressed. Further, it is possible to provide a method for manufacturing such a secondary battery 10.

本実施形態では、正極板２０及び負極板３０の双方は、自身を２等分する中心線ＣＬに対して非対称となるように周端縁を一部切り欠いた切り欠き部２８、３８を有する。一般的にバリ２３，３３は視認することが難しい程度のサイズであるため、その突出方向を目視やセンサ等にて判別しにくいという事情がある。正極板２０が切り欠き部２８を有する構成では、正極板２０における切り欠き部２８の位置を目安にして、正極板２０が正規の向きから表裏反転しているか否かを容易に判別できる。負極板３０が切り欠き部３８を有する構成では、負極板３０における切り欠き部３８の位置を目安にして、負極板３０が正規の向きから表裏反転しているか否かを容易に判別できる。この結果、確実に、正極集電体２１のバリ２３の突出方向と負極集電体３１のバリ３３の突出方向を同じ方向とすることができる。 In the present embodiment, both the positive electrode plate 20 and the negative electrode plate 30 have notches 28, 38 in which the peripheral edge is partially cut out so as to be asymmetric with respect to the center line CL that divides itself into two equal parts. .. In general, the burrs 23 and 33 have a size that is difficult to visually recognize, so that it is difficult to visually determine the protruding direction or by a sensor or the like. In the configuration in which the positive electrode plate 20 has the notch portion 28, it can be easily determined whether or not the positive electrode plate 20 is turned upside down from the normal direction by using the position of the notch portion 28 in the positive electrode plate 20 as a guide. In the configuration in which the negative electrode plate 30 has the notch portion 38, it is possible to easily determine whether or not the negative electrode plate 30 is turned upside down from the normal direction by using the position of the notch portion 38 in the negative electrode plate 30 as a guide. As a result, the protruding direction of the burr 23 of the positive electrode current collector 21 and the protruding direction of the burr 33 of the negative electrode current collector 31 can be surely set to the same direction.

本実施形態では、正極板２０は、板状の正極集電体２１の両面に正極活物質２５が塗布された構成であり、正極集電体２１において正極活物質２５が塗布されていない正極タブ部２７が設けられている。正極タブ部２７には、切り欠き部２８が設けられている。複数の正極板２０は、複数の正極タブ部２７を積層方向に束ねた状態で切り欠き部２８の両側において正極端子１４に溶接されている。この構成によれば、第１溶接部２９Ａと第２溶接部２９Ｂの間に介在する切り欠き部２８を、正極板２０が正規の向きから表裏反転しているか否かを判別するために利用することができる。この結果、確実に、正極集電体２１のバリ２３の突出方向を所定の方向とすることができる。 In the present embodiment, the positive electrode plate 20 has a configuration in which the positive electrode active material 25 is applied to both sides of the plate-shaped positive electrode current collector 21, and the positive electrode tab 20 in which the positive electrode active material 25 is not applied is applied. A section 27 is provided. The positive electrode tab portion 27 is provided with a notch portion 28. The plurality of positive electrode plates 20 are welded to the positive electrode terminals 14 on both sides of the cutout portions 28 in a state where the plurality of positive electrode tab portions 27 are bundled in the stacking direction. According to this configuration, the cutout portion 28 interposed between the first welded portion 29A and the second welded portion 29B is used to determine whether or not the positive electrode plate 20 is turned upside down from the normal orientation. be able to. As a result, the protruding direction of the burr 23 of the positive electrode current collector 21 can be surely set to a predetermined direction.

本実施形態では、負極板３０は、板状の負極集電体３１の両面に負極活物質３５が塗布された構成であり、負極集電体３１において負極活物質３５が塗布されていない負極タブ部３７が設けられている。負極タブ部３７には、切り欠き部３８が設けられている。複数の負極板３０は、複数の負極タブ部３７を積層方向に束ねた状態で切り欠き部３８の両側において負極端子１５に溶接されている。この構成によれば、第１溶接部３９Ａと第２溶接部３９Ｂの間に介在する切り欠き部３８を、負極板３０が正規の向きから表裏反転しているか否かを判別するために利用することができる。この結果、確実に、負極集電体３１のバリ３３の突出方向を所定の方向とすることができる。 In the present embodiment, the negative electrode plate 30 has a configuration in which the negative electrode active material 35 is applied to both sides of the plate-shaped negative electrode current collector 31, and the negative electrode tab 30 in which the negative electrode active material 35 is not applied to the negative electrode current collector 31. A portion 37 is provided. The negative electrode tab portion 37 is provided with a notch portion 38. The plurality of negative electrode plates 30 are welded to the negative electrode terminals 15 on both sides of the notch 38 in a state where the plurality of negative electrode tab portions 37 are bundled in the stacking direction. According to this configuration, the cutout portion 38 interposed between the first welded portion 39A and the second welded portion 39B is used to determine whether or not the negative electrode plate 30 is turned upside down from the normal orientation. be able to. As a result, the protruding direction of the burr 33 of the negative electrode current collector 31 can be surely set to a predetermined direction.

＜他の実施形態＞
上記実施形態は、以下のように変更して実施することができる。また、上記実施形態及び以下の変更例は、技術的に矛盾しない範囲で互いに組み合わせて実施することができる。 <Other Embodiments>
The above embodiment can be modified and implemented as follows. Further, the above-described embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.

上記実施形態では、正極板及び負極板の双方が切り欠き部をそれぞれ有する構成を例示したが、これに限られない。例えば、正極板及び負極板の少なくとも一方が切り欠き部を有する構成であっても、上述のような表裏反転を規定する作用が奏される。また、正極板及び負極板は切り欠き部を有していなくてもよい。その他、切り欠き部の形状、配置は適宜変更可能である。 In the above embodiment, the configuration in which both the positive electrode plate and the negative electrode plate have notches, respectively, is illustrated, but the present invention is not limited to this. For example, even if at least one of the positive electrode plate and the negative electrode plate has a notch portion, the above-mentioned action of defining the front-back inversion is exhibited. Further, the positive electrode plate and the negative electrode plate do not have to have a notch. In addition, the shape and arrangement of the notch portion can be changed as appropriate.

セパレータは、必ずしも不織布によって構成する必要はない。すなわち、セパレータは、例えば延伸フィルムによって構成してもよい。 The separator does not necessarily have to be made of a non-woven fabric. That is, the separator may be made of, for example, a stretched film.

正極集電体には、正極活物質を片面だけにのみ塗布するようにしてもよい。負極集電体には、負極活物質を片面だけにのみ塗布するようにしてもよい。 The positive electrode current collector may be coated with the positive electrode active material on only one side. The negative electrode current collector may be coated with the negative electrode active material on only one side.

二次電池は、リチウムイオン電池以外の二次電池であってもよい。 The secondary battery may be a secondary battery other than the lithium ion battery.

本開示は、次のような実施の形態とされてもよい。
本開示の二次電池において、前記正極板及び前記負極板の少なくとも一方は、自身を２等分する中心線に対して非対称となるように周端縁を一部切り欠いた切り欠き部を有してもよい。 The present disclosure may be in the following embodiments.
In the secondary battery of the present disclosure, at least one of the positive electrode plate and the negative electrode plate has a notch portion in which a peripheral edge is partially cut out so as to be asymmetric with respect to the center line that divides itself into two equal parts. You may.

本開示の二次電池において、前記正極板は、板状の正極集電体における少なくとも一方の面に正極活物質が塗布された構成であり、前記正極集電体において前記正極活物質が塗布されていない正極集電部が設けられており、前記正極集電部には、前記切り欠き部が設けられており、複数の前記正極板は、複数の前記正極集電部を積層方向に束ねた状態で前記切り欠き部の両側において正極端子に溶接されていてもよい。 In the secondary battery of the present disclosure, the positive electrode plate has a configuration in which a positive electrode active material is applied to at least one surface of a plate-shaped positive electrode current collector, and the positive electrode active material is applied to the positive electrode current collector. A positive electrode current collecting portion that is not provided is provided, the positive electrode current collecting portion is provided with the notch portion, and the plurality of positive electrode plates bundle the plurality of the positive electrode current collecting portions in the stacking direction. In this state, the positive electrode terminals may be welded to both sides of the notch.

本開示の二次電池において、前記負極板は、板状の負極集電体における少なくとも一方の面に負極活物質が塗布された構成であり、前記負極集電体において前記負極活物質が塗布されていない負極集電部が設けられており、前記負極集電部には、前記切り欠き部が設けられており、複数の前記負極板は、複数の前記負極集電部を積層方向に束ねた状態で前記切り欠き部の両側において負極端子に溶接されていてもよい。 In the secondary battery of the present disclosure, the negative electrode plate has a configuration in which a negative electrode active material is coated on at least one surface of a plate-shaped negative electrode current collector, and the negative electrode active material is coated on the negative electrode current collector. A negative electrode current collecting portion that is not provided is provided, the negative electrode current collecting portion is provided with the notch portion, and the plurality of the negative electrode plates bundle the plurality of the negative electrode current collecting portions in the stacking direction. In this state, it may be welded to the negative electrode terminals on both sides of the notch.

前述の例は単に説明を目的とするものでしかなく、本発明を限定するものと解釈されるものではない。本発明を典型的な実施形態の例を挙げて説明したが、本発明の記述および図示において使用された文言は、限定的な文言ではなく説明的および例示的なものであると理解される。ここで詳述したように、その形態において本発明の範囲または本質から逸脱することなく、添付の特許請求の範囲内で変更が可能である。ここでは、本発明の詳述に特定の構造、材料および実施例を参照したが、本発明をここにおける開示事項に限定することを意図するものではなく、むしろ、本発明は添付の特許請求の範囲内における、機能的に同等の構造、方法、使用の全てに及ぶものとする。 The above examples are for illustration purposes only and are not to be construed as limiting the invention. Although the present invention has been described with reference to typical embodiments, the language used in the description and illustration of the invention is understood to be descriptive and exemplary rather than restrictive. As described in detail here, modifications can be made within the scope of the appended claims without departing from the scope or nature of the invention in that form. Although specific structures, materials and examples have been referred to herein in detail of the invention, it is not intended to limit the invention to the disclosures herein, but rather the invention is claimed in the accompanying claims. It shall cover all functionally equivalent structures, methods and uses within the scope.

１０…二次電池
１７…電極積層体
２０…正極板
２０Ａ…母材
２１…正極集電体
２１Ａ…アルミニウム箔（正極用金属箔）
２２…周端縁
２３…バリ
３０…負極板
３１…負極集電体
３２…周端縁
３３…バリ
４０…セパレータ 10 ... Secondary battery 17 ... Electrode laminate 20 ... Positive electrode plate 20A ... Base material 21 ... Positive electrode current collector 21A ... Aluminum foil (metal foil for positive electrode)
22 ... Peripheral edge 23 ... Burr 30 ... Negative electrode plate 31 ... Negative electrode current collector 32 ... Peripheral edge 33 ... Burr 40 ... Separator

Claims (2)

正極集電体を有する正極板と、負極集電体を有する負極板とがセパレータを介して積層されてなる電極積層体を備えた二次電池であって、
前記正極集電体は、周端縁の少なくとも一部に、厚さ方向における一方側に向かって突出するバリを有し、
前記負極集電体は、周端縁の少なくとも一部に、厚さ方向における一方側に向かって突出するバリを有し、
前記正極板及び前記負極板は、前記正極集電体のバリの突出方向と前記負極集電体のバリの突出方向を同じ方向とし、前記正極集電体の周端縁と前記負極集電体の周端縁の少なくとも一部が積層方向に重なる形態で積層されていることを特徴とする二次電池。 A secondary battery including an electrode laminate in which a positive electrode plate having a positive electrode current collector and a negative electrode plate having a negative electrode current collector are laminated via a separator.
The positive electrode current collector has burrs protruding toward one side in the thickness direction at least a part of the peripheral edge.
The negative electrode current collector has burrs protruding toward one side in the thickness direction at least a part of the peripheral edge.
The positive electrode plate and the negative electrode plate have the same direction as the protruding direction of the burr of the positive electrode current collector and the protruding direction of the burr of the negative electrode current collector, and the peripheral edge of the positive electrode current collector and the negative electrode current collector. A secondary battery characterized in that at least a part of the peripheral edge of the battery is laminated in a stacking direction. 正極集電体を有する正極板と、負極集電体を有する負極板とがセパレータを介して積層されてなる電極積層体を備えた二次電池の製造方法であって、
前記正極集電体の材料である正極用金属箔に正極活物質が塗布された母材を打ち抜いて、前記正極板を得る工程と、
前記正極集電体の材料である負極用金属箔に負極活物質が塗布された母材を打ち抜いて、前記負極板を得る工程と、
前記正極板が打ち抜かれた方向と前記負極板が打ち抜かれた方向を同じ方向とし、前記正極集電体の周端縁と前記負極集電体の周端縁の少なくとも一部が積層方向に重なる形態で前記正極板及び前記負極板を積層する工程と、を含む二次電池の製造方法。 A method for manufacturing a secondary battery including an electrode laminate in which a positive electrode plate having a positive electrode current collector and a negative electrode plate having a negative electrode current collector are laminated via a separator.
A step of punching out a base material coated with a positive electrode active material on a metal leaf for a positive electrode, which is a material of the positive electrode current collector, to obtain the positive electrode plate.
A step of punching out a base material coated with a negative electrode active material on a metal leaf for a negative electrode, which is a material of the positive electrode current collector, to obtain the negative electrode plate.
The direction in which the positive electrode plate is punched and the direction in which the negative electrode plate is punched are the same, and at least a part of the peripheral edge of the positive electrode current collector and the peripheral edge of the negative electrode current collector overlap in the stacking direction. A method for manufacturing a secondary battery, comprising a step of laminating the positive electrode plate and the negative electrode plate in a form.
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JP2001283897A (en) * 2000-04-04 2001-10-12 Sony Corp Battery and its manufacturing method
JP2016170909A (en) * 2015-03-11 2016-09-23 日立マクセル株式会社 Flat battery
WO2018021128A1 (en) * 2016-07-26 2018-02-01 日本電気株式会社 Electrode assembly and manufacturing method therefor
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Publication number Priority date Publication date Assignee Title
JP2001203001A (en) * 2000-01-18 2001-07-27 Sony Corp Non-aqueous electrolyte battery and its manufacturing method
JP2001283897A (en) * 2000-04-04 2001-10-12 Sony Corp Battery and its manufacturing method
JP2016170909A (en) * 2015-03-11 2016-09-23 日立マクセル株式会社 Flat battery
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JP2019135746A (en) * 2018-02-05 2019-08-15 Tdk株式会社 Electrochemical device

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