JP6702139B2 - Electrode assembly and method of manufacturing electrode assembly - Google Patents

Electrode assembly and method of manufacturing electrode assembly Download PDF

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JP6702139B2
JP6702139B2 JP2016213643A JP2016213643A JP6702139B2 JP 6702139 B2 JP6702139 B2 JP 6702139B2 JP 2016213643 A JP2016213643 A JP 2016213643A JP 2016213643 A JP2016213643 A JP 2016213643A JP 6702139 B2 JP6702139 B2 JP 6702139B2
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active material
material layer
separators
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幹也 栗田
幹也 栗田
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Toyota Industries 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
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Description

本発明は、電極組立体及び電極組立体の製造方法に関するものである。   The present invention relates to an electrode assembly and a method for manufacturing the electrode assembly.

リチウムイオン二次電池等の蓄電装置は電極組立体を有し、電極組立体は、正極電極及び負極電極がセパレータを介在する状態で複数枚積層して配置されている。積層枚数が増えると、積層時に位置ズレが発生し易くなる為、位置ズレ等を抑えるために予め電極とセパレータを重ねて配置してある程度ユニット化したものを用意し、これを積層して配置する技術がある（例えば特許文献１）。特許文献１には、第１極性電極・分離膜・第２極性電極・分離膜・第１極性電極よりなる第１スタック型セルと、分離膜・第２極性電極・分離膜・第１極性電極・分離膜・第２極性電極・分離膜よりなる第２スタック型セルを、複数交互に積層することが記載されている。   A power storage device such as a lithium-ion secondary battery has an electrode assembly, and the electrode assembly is arranged by stacking a plurality of positive and negative electrodes with a separator interposed therebetween. As the number of stacked layers increases, positional deviation easily occurs during stacking.Therefore, in order to suppress positional deviation, etc., an electrode and a separator are preliminarily placed on top of each other so that they are unitized to some extent, and then these are placed on top of each other. There is a technology (for example, Patent Document 1). Patent Document 1 discloses a first stack type cell including a first polarity electrode, a separation film, a second polarity electrode, a separation film, and a first polarity electrode, and a separation film, a second polarity electrode, a separation film, and a first polarity electrode. It is described that a plurality of second stack type cells each including a separation film, a second polar electrode and a separation film are alternately laminated.

特表２０１３−５２４４６０号公報Special table 2013-524460 gazette

特許文献１では、ユニット化のために、第１極性電極と分離膜、分離膜と第２極性電極との間を個々に接着剤を用いて固定しているので、例えば、接着剤の成分が電解液内に混入してしまい性能が不安定となるといったことが懸念される。   In Patent Document 1, since the first polar electrode and the separation film and the separation film and the second polar electrode are individually fixed with an adhesive for unitization, for example, the component of the adhesive is There is concern that the performance may become unstable due to mixing in the electrolytic solution.

本発明の目的は、性能に影響を出にくくすることができる電極組立体及び電極組立体の製造方法を提供することにある。   An object of the present invention is to provide an electrode assembly and a method of manufacturing the electrode assembly that can reduce the influence on the performance.

請求項１に記載の発明では、金属箔の少なくとも一方の面に活物質層が形成された複数枚の正極電極、及び、金属箔の少なくとも一方の面に活物質層が形成された複数枚の負極電極が、セパレータを介在させた状態で交互に積層された電極組立体であって、二枚のセパレータ間に前記正極電極が挟まれた積層体に前記負極電極が積層され、前記二枚のセパレータにおける前記正極電極からはみ出る領域と負極電極の金属箔における前記活物質層が形成されていない活物質層非形成領域とが重なった部位に凹凸の噛み合わせにより接合された接合部を有することを要旨とする。   In the invention according to claim 1, a plurality of positive electrode electrodes having an active material layer formed on at least one surface of the metal foil, and a plurality of positive electrode electrodes having an active material layer formed on at least one surface of the metal foil. The negative electrode is an electrode assembly that is alternately laminated with a separator interposed, and the negative electrode is laminated in a laminated body in which the positive electrode is sandwiched between two separators, and the two negative electrodes are laminated. A region protruding from the positive electrode of the separator and a region of the metal foil of the negative electrode where the active material layer is not formed have an active material layer-unformed region that has a joint portion that is joined by meshing of unevenness. Use as a summary.

請求項１に記載の発明によれば、二枚のセパレータ間に正極電極が挟まれた積層体に負極電極が積層されており、二枚のセパレータにおける正極電極からはみ出る領域と負極電極の金属箔における活物質層が形成されていない活物質層非形成領域とが重なった部位は、凹凸の噛み合わせにより接合された接合部となっている。よって、接着剤を用いて固定しておらず、例えば、接着剤の成分が電解液内に混入するといったことが回避され、性能に影響を出にくくすることができる。   According to the invention described in claim 1, the negative electrode is laminated on the laminated body in which the positive electrode is sandwiched between the two separators, and the metal foil of the negative electrode and the region protruding from the positive electrode in the two separators. The region where the active material layer-non-formed region in which the active material layer is not formed overlaps with each other is a joint portion that is joined by the engagement of the unevenness. Therefore, it is possible to prevent the components of the adhesive from being mixed in the electrolytic solution without being fixed by using the adhesive, and it is possible to prevent the performance from being adversely affected.

請求項２に記載のように、請求項１に記載の電極組立体において、前記接合部は、矩形状の前記二枚のセパレータの角部及び矩形状の前記負極電極の角部に形成されているとよい。   As described in claim 2, in the electrode assembly according to claim 1, the joint portion is formed at a corner portion of the two separators having a rectangular shape and a corner portion of the negative electrode having a rectangular shape. I hope you are there.

請求項３に記載のように、請求項１または２に記載の電極組立体において、前記二枚のセパレータと前記正極電極との積層体は２組有し、２組の積層体の間に前記負極電極が挟まれており、前記接合部は、２組の積層体での前記二枚のセパレータにおける前記正極電極からはみ出る領域と負極電極の金属箔における前記活物質層が形成されていない活物質層非形成領域とが重なった部位に形成されているとよい。   As described in claim 3, in the electrode assembly according to claim 1 or 2, there are two sets of laminates of the two separators and the positive electrode, and between the two sets of laminates. The negative electrode is sandwiched between the active material layer in which the active material layer in the metal foil of the negative electrode and the region protruding from the positive electrode in the two separators in the two sets of laminated body are sandwiched It is preferable that the layer non-formation region is formed in an overlapping portion.

請求項４に記載のように、請求項１〜３のいずれか１項に記載の電極組立体において、前記二枚のセパレータにおける前記接合部は溶着されているとよい。
請求項５に記載のように、請求項２に記載の電極組立体において、前記凹凸は対角方向に延びているとよい。 As described in claim 4, in the electrode assembly according to any one of claims 1 to 3, it is preferable that the joint portions of the two separators are welded.
According to a fifth aspect, in the electrode assembly according to the second aspect, the unevenness may extend in a diagonal direction.

請求項６に記載の発明では、金属箔の少なくとも一方の面に活物質層が形成された複数枚の正極電極、及び、金属箔の少なくとも一方の面に活物質層が形成された複数枚の負極電極が、セパレータを介在させた状態で交互に積層された電極組立体の製造方法であって、二枚のセパレータ間に前記正極電極を挟んで積層するとともに、この積層体に前記負極電極を積層する第１工程と、第１工程後に、前記二枚のセパレータにおける正極電極からはみ出る領域と負極電極の金属箔における活物質層が形成されていない活物質層非形成領域とが重なった部位を、凹凸の噛み合わせにより接合する第２工程と、を有することを要旨とする。   In the invention according to claim 6, a plurality of positive electrodes having an active material layer formed on at least one surface of the metal foil, and a plurality of positive electrodes having an active material layer formed on at least one surface of the metal foil. A negative electrode is a method of manufacturing an electrode assembly in which separators are alternately laminated, and the positive electrode is sandwiched between two separators, and the negative electrode is added to the laminate. After the first step of stacking, a portion where the area protruding from the positive electrode of the two separators and the active material layer non-forming area of the metal foil of the negative electrode where the active material layer is not formed overlap with each other after the first step. And a second step of joining by engaging the concavities and convexities with each other.

請求項６に記載の発明によれば、第１工程において、二枚のセパレータ間に正極電極を挟んで積層されるとともに、この積層体に負極電極が積層される。第２工程において、第１工程後に、二枚のセパレータにおける正極電極からはみ出る領域と負極電極の金属箔における活物質層が形成されていない活物質層非形成領域とが重なった部位が、凹凸の噛み合わせにより接合される。これにより、請求項１に記載の電極組立体が製造される。   According to the invention of claim 6, in the first step, the positive electrode is sandwiched between the two separators, and the negative electrode is laminated on the laminated body. In the second step, after the first step, a portion of the two separators protruding from the positive electrode and a region of the metal foil of the negative electrode where the active material layer is not formed are overlapped with each other. Joined by biting. Thereby, the electrode assembly according to claim 1 is manufactured.

請求項７に記載の発明では、金属箔の少なくとも一方の面に活物質層が形成された複数枚の正極電極、及び、金属箔の少なくとも一方の面に活物質層が形成された複数枚の負極電極が、セパレータを介在させた状態で交互に積層された電極組立体の製造方法であって、二枚のセパレータ間に前記正極電極を挟んで積層した二組の積層体の間に負極電極を積層する第１工程と、第１工程後に、前記二組の積層体での前記二枚のセパレータにおける正極電極からはみ出る領域と負極電極の金属箔における活物質層が形成されていない活物質層非形成領域とが重なった部位を、凹凸の噛み合わせにより接合する第２工程と、を有することを要旨とする。   In the invention according to claim 7, a plurality of positive electrode electrodes having an active material layer formed on at least one surface of the metal foil, and a plurality of positive electrode electrodes having an active material layer formed on at least one surface of the metal foil. A method for manufacturing an electrode assembly in which negative electrodes are alternately stacked with a separator interposed, wherein the negative electrode is sandwiched between two separators and the positive electrode is sandwiched between the two negative electrodes. A first step of laminating the active material layer in the metal foil of the negative electrode and a region protruding from the positive electrode of the two separators in the two sets of laminated bodies after the first step. The gist of the present invention is to have a second step of joining a portion where the non-formation region overlaps with each other by meshing the concave and convex portions.

請求項７に記載の発明によれば、第１工程において、二枚のセパレータ間に正極電極を挟んで積層した二組の積層体の間に負極電極が積層される。第２工程において、第１工程後に、二組の積層体での二枚のセパレータにおける正極電極からはみ出る領域と負極電極の金属箔における活物質層が形成されていない活物質層非形成領域とが重なった部位が、凹凸の噛み合わせにより接合される。これにより、請求項３に記載の電極組立体が製造される。   According to the invention of claim 7, in the first step, the negative electrode is laminated between the two sets of laminated bodies in which the positive electrode is sandwiched between the two separators. In the second step, after the first step, a region protruding from the positive electrode in the two separators in the two sets of laminates and an active material layer non-forming region in the metal foil of the negative electrode where the active material layer is not formed are formed. The overlapping portions are joined by the engagement of the unevenness. Thereby, the electrode assembly according to claim 3 is manufactured.

本発明によれば、性能に影響を出にくくすることができる。   According to the present invention, it is possible to prevent the performance from being affected.

（ａ）は電極組立体のユニットの概略平面図、（ｂ）はユニットの概略側面図、（ｃ）は（ａ）のＡ−Ａ線での断面図。(A) is a schematic plan view of a unit of an electrode assembly, (b) is a schematic side view of the unit, (c) is a sectional view taken along the line AA of (a). （ａ）は負極電極の概略平面図、（ｂ）は負極電極の概略側面図、（ｃ）は（ａ）のＡ−Ａ線での断面図。(A) is a schematic plan view of a negative electrode, (b) is a schematic side view of a negative electrode, (c) is sectional drawing in the AA line of (a). （ａ）はセパレータ及び正極電極の概略平面図、（ｂ）は（ａ）のＡ−Ａ線での断面図、（ｃ）は（ａ）のＢ−Ｂ線での断面図。(A) is a schematic plan view of a separator and a positive electrode, (b) is sectional drawing in the AA line of (a), (c) is sectional drawing in the BB line of (a). （ａ）はユニットの一部平面図、（ｂ）は（ａ）のＡ−Ａ線での断面図、（ｃ）は（ａ）のＢ−Ｂ線での断面図。(A) is a partial plan view of the unit, (b) is a sectional view taken along line AA of (a), and (c) is a sectional view taken along line BB of (a). ユニットの製造工程を説明するための斜視図。FIG. 6 is a perspective view for explaining a manufacturing process of the unit. ユニットの製造装置を説明するための正面図。The front view for demonstrating the manufacturing apparatus of a unit. 別例のユニットの一部平面図。The partial top view of the unit of another example. （ａ）は別例のユニットの概略平面図、（ｂ）はユニットの概略側面図、（ｃ）は（ａ）のＡ−Ａ線での断面図。(A) is a schematic plan view of a unit of another example, (b) is a schematic side view of the unit, (c) is a sectional view taken along the line AA of (a).

以下、本発明を具体化した一実施形態を図面に従って説明する。
蓄電装置としてのリチウムイオン二次電池は電極組立体を有しており、電極組立体はケース内に配置される。また、ケース内には、電極組立体に含浸されるのに十分な量の電解液が注入されている。電極組立体は、矩形状の複数枚の正極電極２０（図３（ａ），（ｂ），（ｃ）参照）、及び、矩形状の複数枚の負極電極３０（図２（ａ），（ｂ），（ｃ）参照）が、単層セパレータ４１，４２（図３（ａ），（ｂ），（ｃ）参照）を介在させた状態で交互に積層されている。図１（ａ），（ｂ），（ｃ）では、電極組立体の一部を示し、矩形状の正極電極２０及び矩形状の負極電極３０が袋状セパレータ４０（単層セパレータ４１，４２）を介在させた状態で積層され、矩形状のユニットＵｎとなっている。このユニットＵｎが複数積層され、ユニットＵｎ／ユニットＵｎ／・・・と重ねられて電極組立体が構成される。 Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
A lithium ion secondary battery as a power storage device has an electrode assembly, and the electrode assembly is arranged in a case. In addition, an electrolyte solution is injected into the case in an amount sufficient to impregnate the electrode assembly. The electrode assembly includes a plurality of rectangular positive electrodes 20 (see FIGS. 3A, 3B, and 3C) and a plurality of rectangular negative electrodes 30 (FIGS. 2A and 2C). b) and (c)) are alternately laminated with the single-layer separators 41 and 42 (see FIGS. 3A, 3B, and 3C) interposed. 1A, 1B, and 1C, a part of the electrode assembly is shown, and the rectangular positive electrode 20 and the rectangular negative electrode 30 are bag-shaped separators 40 (single-layer separators 41 and 42). Are stacked in a state where they are interposed to form a rectangular unit Un. A plurality of the units Un are stacked and stacked with the unit Un/unit Un/... to form an electrode assembly.

図３（ａ），（ｂ），（ｃ）に示すように、正極電極２０は、矩形シート状の正極金属箔（本実施形態ではアルミニウム箔）２１と、その正極金属箔２１の両面に形成された矩形状の正極活物質層２２と、を有する。正極金属箔２１の両面の正極活物質層２２は、同じ平面形状及び同じ厚みであり、かつ正極金属箔２１を挟んで互いに対向している。正極金属箔２１において、第１の辺２１ａの一部には、正極タブ２５が突出する状態に設けられている。なお、正極タブ２５は、第１の辺２１ａからの突出方向に沿って一定幅で延びている。正極金属箔２１において、正極タブ２５が設けられた第１の辺２１ａの対辺となる長辺を第２の辺２１ｂとする。また、正極金属箔２１において、第１の辺２１ａと第２の辺２１ｂを繋ぐ一対の辺（短辺）のうち、一方の辺を第３の辺２１ｃとし、他方の辺を第４の辺２１ｄとする。   As shown in FIGS. 3A, 3</b>B, and 3</b>C, the positive electrode 20 is formed on both sides of a rectangular sheet-shaped positive metal foil (aluminum foil in this embodiment) 21. Rectangular shaped positive electrode active material layer 22. The positive electrode active material layers 22 on both surfaces of the positive electrode metal foil 21 have the same planar shape and the same thickness, and face each other with the positive electrode metal foil 21 interposed therebetween. In the positive electrode metal foil 21, a positive electrode tab 25 is provided in a protruding state on a part of the first side 21a. The positive electrode tab 25 extends with a constant width along the protruding direction from the first side 21a. In the positive electrode metal foil 21, a long side opposite to the first side 21a provided with the positive electrode tab 25 is defined as a second side 21b. In addition, in the positive electrode metal foil 21, of the pair of sides (short sides) connecting the first side 21a and the second side 21b, one side is the third side 21c and the other side is the fourth side. 21d.

なお、正極電極２０は金属箔２１の両方の面に活物質層２２がそれぞれ形成されていなくてもよく、正極電極２０は、金属箔２１の少なくとも一方の面に活物質層２２が形成されていればよい。   The positive electrode 20 does not need to have the active material layer 22 formed on both surfaces of the metal foil 21, and the positive electrode 20 has the active material layer 22 formed on at least one surface of the metal foil 21. Just do it.

図２（ａ），（ｂ），（ｃ）に示すように、負極電極３０は、矩形シート状の負極金属箔（本実施形態では銅箔）３１と、その負極金属箔３１の両面に形成された矩形状の負極活物質層３２と、を有する。負極金属箔３１の両面の負極活物質層３２は、同じ平面形状及び同じ厚みであり、かつ負極金属箔３１を挟んで互いに対向している。負極金属箔３１において、第１の辺３１ａの一部には、負極タブ３５が突出する状態に設けられている。なお、負極タブ３５は、第１の辺３１ａからの突出方向に沿って一定幅で延びている。負極電極３０において、負極タブ３５が設けられた第１の辺３１ａの対辺となる長辺を第２の辺３１ｂとする。また、負極電極３０において、第１の辺３１ａと第２の辺３１ｂを繋ぐ一対の辺（短辺）のうち、一方の辺を第３の辺３１ｃとし、他方の辺を第４の辺３１ｄとする。負極電極３０は、第１〜第４の辺３１ａ〜３１ｄに沿って、負極活物質層３２の存在しない活物質層非形成領域（未塗工部）３３を有する。よって、活物質層非形成領域（未塗工部）３３は、負極活物質層３２を囲む四角環状である。   As shown in FIGS. 2A, 2</b>B, and 2</b>C, the negative electrode 30 is formed on both sides of the negative electrode metal foil 31 (copper foil in this embodiment) 31 in the form of a rectangular sheet. Rectangular shaped negative electrode active material layer 32. The negative electrode active material layers 32 on both surfaces of the negative electrode metal foil 31 have the same planar shape and the same thickness, and face each other with the negative electrode metal foil 31 interposed therebetween. In the negative electrode metal foil 31, a negative electrode tab 35 is provided in a protruding state on a part of the first side 31a. The negative electrode tab 35 extends with a constant width along the protruding direction from the first side 31a. In the negative electrode 30, a long side opposite to the first side 31a provided with the negative electrode tab 35 is referred to as a second side 31b. Further, in the negative electrode 30, of the pair of sides (short sides) connecting the first side 31a and the second side 31b, one side is the third side 31c and the other side is the fourth side 31d. And The negative electrode 30 has an active material layer non-forming region (uncoated portion) 33 in which the negative electrode active material layer 32 does not exist along the first to fourth sides 31a to 31d. Therefore, the active material layer non-forming region (uncoated portion) 33 is a square ring surrounding the negative electrode active material layer 32.

負極電極３０の活物質層非形成領域（未塗工部）３３のうち四隅は直線的に延びる斜状面３２ａと辺３１ａ，３１ｂ，３１ｃ，３１ｄとで囲まれた領域である。つまり、四隅は、長方形状の金属箔３１の縁による２辺と直線的に延びる斜状面３２ａよりなる直角三角形状をなしている。   The four corners of the active material layer non-formed region (uncoated portion) 33 of the negative electrode 30 are regions surrounded by the linearly extending slanted surface 32a and the sides 31a, 31b, 31c, 31d. That is, the four corners are in the shape of a right triangle having two sides formed by the edges of the rectangular metal foil 31 and the inclined surface 32a extending linearly.

なお、負極電極３０は金属箔３１の両方の面に活物質層３２がそれぞれ形成されていたが、負極電極３０は、金属箔３１の少なくとも一方の面に活物質層３２が形成されていればよい。   The negative electrode 30 had the active material layers 32 formed on both surfaces of the metal foil 31, respectively. However, the negative electrode 30 has the active material layer 32 formed on at least one surface of the metal foil 31. Good.

図１（ａ），（ｂ），（ｃ）に示すように、正極電極２０及び負極電極３０において、負極活物質層３２の隣り合う二辺の各辺の長さ（長辺に沿う長さ及び短辺に沿う長さ）は、正極活物質層２２の隣り合う二辺の各辺の長さ（長辺に沿う長さ及び短辺に沿う長さ）よりも長く設定されている。負極活物質層３２は、正極活物質層２２の全面を覆うことが可能な大きさに設定されている。また、負極電極３０の第１の辺３１ａ及び第２の辺３１ｂの長さは、正極電極２０の第１の辺２１ａと第２の辺２１ｂの長さより長く設定されている。さらに、負極電極３０の第３の辺３１ｃと第４の辺３１ｄの長さは、正極電極２０の第３の辺２１ｃと第４の辺２１ｄの長さより長く設定されている。つまり、負極電極３０の平面視でのサイズは、正極電極２０の平面視でのサイズより一回り大きい。   As shown in FIGS. 1A, 1</b>B, and 1</b>C, in the positive electrode 20 and the negative electrode 30, the length of each of two adjacent sides of the negative electrode active material layer 32 (the length along the long side). And the length along the short side) is set to be longer than the length of each of the two adjacent sides of the positive electrode active material layer 22 (the length along the long side and the length along the short side). The negative electrode active material layer 32 is set to a size capable of covering the entire surface of the positive electrode active material layer 22. The lengths of the first side 31a and the second side 31b of the negative electrode 30 are set to be longer than the lengths of the first side 21a and the second side 21b of the positive electrode 20. Further, the lengths of the third side 31c and the fourth side 31d of the negative electrode 30 are set to be longer than the lengths of the third side 21c and the fourth side 21d of the positive electrode 20. That is, the size of the negative electrode 30 in plan view is slightly larger than the size of the positive electrode 20 in plan view.

図３（ａ），（ｂ），（ｃ）に示すように、袋状セパレータ４０に正極電極２０が収納されている。袋状セパレータ４０において、正極電極２０の第１の辺２１ａに沿って延びる一辺（長辺）を第１の辺４０ａとし、第１の辺４０ａの対辺で、かつ正極電極２０の第２の辺２１ｂに沿って延びる辺（長辺）を第２の辺４０ｂとする。また、袋状セパレータ４０において、第１の辺４０ａと第２の辺４０ｂを繋ぎ、かつ正極電極２０の第３の辺２１ｃに沿って延びる辺（短辺）を第３の辺４０ｃとし、第４の辺２１ｄに沿って延びる辺（短辺）を第４の辺４０ｄとする。   As shown in FIGS. 3A, 3B, and 3C, the positive electrode 20 is housed in the bag-shaped separator 40. In the bag-shaped separator 40, one side (long side) extending along the first side 21a of the positive electrode 20 is referred to as a first side 40a, which is a side opposite to the first side 40a and a second side of the positive electrode 20. A side (long side) extending along 21b is defined as a second side 40b. In the bag-shaped separator 40, the side (short side) that connects the first side 40a and the second side 40b and extends along the third side 21c of the positive electrode 20 is defined as the third side 40c, and The side (short side) extending along the fourth side 21d is defined as a fourth side 40d.

袋状セパレータ４０は、二枚の単層セパレータ４１，４２を熱溶着によって接合して袋状に形成されている。二枚の単層セパレータ４１，４２は、樹脂（例えばポリプロピレン）からなり、多孔質のシート状をなしている。二枚の単層セパレータ４１，４２は、互いに対峙している。また、二枚の単層セパレータ４１，４２は、正極電極２０の両面を覆う大きさで、かつ同一の大きさの矩形状である。袋状セパレータ４０は、二枚の単層セパレータ４１，４２で形成された収納部に正極電極２０が収納されている。二枚の単層セパレータ４１，４２は、正極電極２０の面に沿う方向に沿って、正極電極２０の第１〜第４の辺２１ａ〜２１ｄからはみ出る領域（はみ出し領域）４３を備える。袋状セパレータ４０は、二枚の単層セパレータ４１，４２における互いに対峙するはみ出し領域４３同士を熱溶着して形成されている。   The bag-shaped separator 40 is formed in a bag shape by joining two single-layer separators 41 and 42 by heat welding. The two single-layer separators 41, 42 are made of resin (for example, polypropylene) and have a porous sheet shape. The two single-layer separators 41 and 42 face each other. In addition, the two single-layer separators 41 and 42 have a rectangular shape having a size that covers both surfaces of the positive electrode 20 and the same size. In the bag-shaped separator 40, the positive electrode 20 is stored in the storage portion formed by the two single-layer separators 41 and 42. The two single-layer separators 41, 42 include a region (protrusion region) 43 protruding from the first to fourth sides 21a to 21d of the positive electrode 20 along the direction along the surface of the positive electrode 20. The bag-shaped separator 40 is formed by thermally welding the protruding regions 43 of the two single-layer separators 41 and 42 facing each other.

正極電極２０のタブ２５は、袋状セパレータ（電極収納セパレータ）４０の縁部から突出している。図１（ａ），（ｂ），（ｃ）に示すように、負極電極３０の負極タブ３５と、袋状セパレータ４０に収納された正極電極２０の正極タブ２５とは、積層した状態において重ならないように位置している。   The tab 25 of the positive electrode 20 projects from the edge portion of the bag-shaped separator (electrode storage separator) 40. As shown in FIGS. 1A, 1</b>B, and 1</b>C, the negative electrode tab 35 of the negative electrode 30 and the positive electrode tab 25 of the positive electrode 20 housed in the bag-shaped separator 40 are stacked in a stacked state. It is located so as not to become.

図１（ａ），（ｂ），（ｃ）に示すように、二枚の単層セパレータ４１，４２間に正極電極２０が挟まれた積層体６０に負極電極３０が積層され、凹凸の噛み合わせにより接合された接合部５０を四隅に有する。接合部５０は、二枚の単層セパレータ４１，４２における正極電極２０からはみ出る領域４３と、負極電極３０の金属箔３１における活物質層３２が形成されていない活物質層非形成領域３３とが重なった部位６１に設けられている。   As shown in FIGS. 1A, 1</b>B, and 1</b>C, the negative electrode 30 is stacked on the stacked body 60 in which the positive electrode 20 is sandwiched between the two single-layer separators 41 and 42, and the unevenness is bitten. It has the joint part 50 joined by joining in four corners. The joining portion 50 includes a region 43 protruding from the positive electrode 20 in the two single-layer separators 41 and 42 and an active material layer non-forming region 33 in which the active material layer 32 in the metal foil 31 of the negative electrode 30 is not formed. It is provided in the overlapping portion 61.

つまり、矩形状の二枚の単層セパレータ４１，４２の角部４３ａ，４３ｂ，４３ｃ，４３ｄ、及び、矩形状の負極電極３０の角部３３ａ，３３ｂ，３３ｃ，３３ｄが接合部５０となっている。矩形状の二枚の単層セパレータ４１，４２の角部４３ａ，４３ｂ，４３ｃ，４３ｄは、二枚の単層セパレータ４１，４２における正極電極２０からはみ出る領域４３であり、矩形状の負極電極３０の角部３３ａ，３３ｂ，３３ｃ，３３ｄは、負極電極３０の金属箔３１における活物質層３２が形成されていない活物質層非形成領域（未塗工部）３３である。   That is, the corner portions 43a, 43b, 43c, 43d of the two rectangular single-layer separators 41, 42 and the corner portions 33a, 33b, 33c, 33d of the rectangular negative electrode 30 become the joint portion 50. There is. The corner portions 43a, 43b, 43c, 43d of the two rectangular single-layer separators 41, 42 are regions 43 protruding from the positive electrode 20 in the two single-layer separators 41, 42, and the rectangular negative electrode 30 The corner portions 33a, 33b, 33c, 33d are active material layer non-forming regions (uncoated portions) 33 in which the active material layer 32 in the metal foil 31 of the negative electrode 30 is not formed.

図４（ａ），（ｂ）に示すように、接合部５０は複数の凹凸５１を有し、複数の凹凸５１は、長方形状のユニットＵｎの対角方向に直交する方向において並設されている。図４（ａ），（ｃ）に示すように、各凹凸５１は、長方形状のユニットＵｎの対角方向に延びている。   As shown in FIGS. 4A and 4B, the joint portion 50 has a plurality of concavities and convexities 51, and the plurality of concavities and convexities 51 are juxtaposed in a direction orthogonal to the diagonal direction of the rectangular unit Un. There is. As shown in FIGS. 4A and 4C, each unevenness 51 extends in a diagonal direction of the rectangular unit Un.

矩形状の二枚の単層セパレータ４１，４２の角部４３ａ，４３ｂ，４３ｃ，４３ｄは、二枚の単層セパレータ４１，４２における正極電極２０からはみ出る領域４３であり、領域４３以外では、単層セパレータ４１，４２は溶着されていない。従って、正極電極２０の外周について、領域４３に対応しない箇所では、溶着代を考慮することなく、正極電極２０の活物質層の大きさを、負極活物質層に近づけることが出来ることから、活物質層同士の対向面積が接合部以外最大限大きくされ、容量アップが図られている。   The corner portions 43a, 43b, 43c, 43d of the two rectangular single-layer separators 41, 42 are regions 43 protruding from the positive electrode 20 in the two single-layer separators 41, 42, and other than the region 43, The layer separators 41 and 42 are not welded. Therefore, on the outer periphery of the positive electrode 20, the size of the active material layer of the positive electrode 20 can be made closer to that of the negative electrode active material layer without considering the welding margin at a portion that does not correspond to the region 43. The area where the material layers face each other is maximized except for the joint portion, thereby increasing the capacity.

図５及び図６に示すように、接合装置７０は、上型７１と下型７２を備えている。上型７１及び下型７２は、少なくとも一方が互いに接近する方向に移動可能となっている。上型７１の下面には歯７３が形成されている。下型７２の上面には歯７４が形成されている。図５に示すように、上型７１と下型７２との間に、ユニットＵｎの角部（二枚の単層セパレータ４１，４２における正極電極２０からはみ出る領域４３と負極電極３０の金属箔３１における活物質層３２が形成されていない活物質層非形成領域３３とが重なった部位）を配置する。この状態で上型７１と下型７２とを互いに接近するように挟み込み、上型７１の歯７３と下型７２の歯７４との間で、凹凸の噛み合わせにより、接合することができる。   As shown in FIGS. 5 and 6, the joining device 70 includes an upper die 71 and a lower die 72. At least one of the upper die 71 and the lower die 72 is movable in a direction in which they approach each other. Teeth 73 are formed on the lower surface of the upper mold 71. Teeth 74 are formed on the upper surface of the lower die 72. As shown in FIG. 5, between the upper mold 71 and the lower mold 72, the corner portion of the unit Un (the region 43 protruding from the positive electrode 20 in the two single-layer separators 41 and 42 and the metal foil 31 of the negative electrode 30). A region where the active material layer 32 in which the active material layer 32 is not formed is overlapped). In this state, the upper die 71 and the lower die 72 can be sandwiched so as to be close to each other, and the teeth 73 of the upper die 71 and the teeth 74 of the lower die 72 can be joined by the engagement of the unevenness.

上型７１の歯７３及び下型７２の歯７４は、単に三角形を繰り返したギザギザの形状にするのではなく、図６に示すように、上型７１の歯７３及び下型７２の歯７４は、平坦面７５，７６を設けて単層セパレータ４１，４２の破れが生じにくいようにすると更によい。また、他にも、上型７１の歯７３及び下型７２の歯７４は、先端の角部（エッジ部）７３ａ，７４ａはＲ（アール）を付けて単層セパレータ４１，４２の破れが生じにくいようにしてもよい。さらに、上型７１の歯７３及び下型７２の歯７４は、平坦面７５，７６を設けるとともに先端の角部７３ａ，７４ａはＲを付けてもよい。   The teeth 73 of the upper die 71 and the teeth 74 of the lower die 72 do not have to have a serrated shape in which triangles are repeated, but as shown in FIG. It is more preferable to provide flat surfaces 75 and 76 to prevent the single-layer separators 41 and 42 from breaking. In addition, the teeth 73 of the upper die 71 and the teeth 74 of the lower die 72 are provided with R (R) at the corner portions (edge portions) 73a and 74a at the tips to cause breakage of the single-layer separators 41 and 42. You may make it difficult. Further, the teeth 73 of the upper die 71 and the teeth 74 of the lower die 72 may be provided with flat surfaces 75 and 76, and the corner portions 73a and 74a at the tips may be rounded.

次に、電極組立体の製造方法について説明する。
まず、図３（ａ），（ｂ），（ｃ）に示すように、二枚の単層セパレータ４１，４２間に正極電極２０を挟んで積層するとともに、この積層体６０に図２（ａ），（ｂ），（ｃ）に示す負極電極３０を積層する。 Next, a method for manufacturing the electrode assembly will be described.
First, as shown in FIGS. 3( a ), 3 (b ), and 3 (c ), the positive electrode 20 is sandwiched between two single-layer separators 41 and 42, and the laminated body 60 is stacked. ), (b) and (c) are laminated.

このとき、二枚の単層セパレータ４１，４２間に正極電極２０が挟まれた状態において、二枚の単層セパレータ４１，４２における全周は、角部、即ち、凹凸の噛み合わせによる接合予定領域を含めて溶着されている。   At this time, in the state where the positive electrode 20 is sandwiched between the two single-layer separators 41 and 42, the entire circumference of the two single-layer separators 41 and 42 is planned to be joined by the engagement of the corners, that is, the unevenness. It is welded including the area.

そして、図５に示すように、接合装置７０を用いて二枚の単層セパレータ４１，４２における正極電極２０からはみ出る領域４３と負極電極３０の金属箔３１における活物質層３２が形成されていない活物質層非形成領域３３とが重なった部位６１を、凹凸の噛み合わせにより接合する。   Then, as shown in FIG. 5, the region 43 protruding from the positive electrode 20 in the two single-layer separators 41 and 42 and the active material layer 32 in the metal foil 31 of the negative electrode 30 are not formed using the joining device 70. The part 61 where the active material layer non-formation region 33 overlaps is joined by meshing of irregularities.

凹凸の噛み合わせによる接合は、矩形状の二枚の単層セパレータ４１，４２の角部４３ａ，４３ｂ，４３ｃ，４３ｄ及び矩形状の負極電極３０の角部３３ａ，３３ｂ，３３ｃ，３３ｄで行われる。   The joining by the meshing of the unevenness is performed at the corners 43a, 43b, 43c, 43d of the two rectangular single-layer separators 41, 42 and the corners 33a, 33b, 33c, 33d of the rectangular negative electrode 30. ..

このようにして、単層セパレータ４１，４２で包まれた正極電極２０と負極電極３０とを重ねて接合したユニットＵｎを複数積層して電極組立体を構成する。
そして、このようにして構成した電極組立体がケース内に配置され、さらに、ケース内に電解液が注入される。 In this manner, a plurality of units Un in which the positive electrode 20 and the negative electrode 30 wrapped with the single-layer separators 41 and 42 are superposed and joined are laminated to form an electrode assembly.
Then, the electrode assembly thus configured is placed in the case, and further, the electrolytic solution is injected into the case.

このようにして蓄電装置としてのリチウムイオン二次電池が製造される。
次に、ユニットＵｎの接合方式として、型７１，７２の歯７３，７４を用いて金属箔３１及び単層セパレータ４１，４２に対し凸凹の噛み合わせより接合する方式と他の方式を用いた場合を対比する。 In this way, a lithium ion secondary battery as a power storage device is manufactured.
Next, as the joining method of the unit Un, a method of joining the metal foil 31 and the single-layer separators 41, 42 by the meshing of unevenness using the teeth 73, 74 of the molds 71, 72 and another method are used. Contrast.

本実施形態の凸凹の噛み合わせより接合する方式においては、波形状の歯７３，７４で破かないよう金属箔３１及び単層セパレータ４１，４２を引き伸ばして圧力で再び固めることで金属箔３１及び単層セパレータ４１，４２を接合することができる。即ち、図５に示すように、波形状の歯７３，７４を有する上型７１及び下型７２の間に、金属箔３１及び単層セパレータ４１，４２の積層体６０の角部を配置して、積層体６０の角部を圧着して接合が行われる。   In the method of joining by means of the uneven meshing of the present embodiment, the metal foil 31 and the single-layer separators 41, 42 are stretched so as not to be broken by the corrugated teeth 73, 74, and the metal foil 31 and the single-layer separators are solidified again by pressure. The layer separators 41, 42 can be joined. That is, as shown in FIG. 5, the corners of the laminate 60 of the metal foil 31 and the single-layer separators 41, 42 are arranged between the upper mold 71 and the lower mold 72 having the wavy teeth 73, 74. Then, the corner portions of the laminated body 60 are pressure-bonded to perform the joining.

これに対し、一般的なユニット化の手段として、接着剤により接合する方式とした場合には、接着剤の成分が電解液内に混入する虞がある。本実施形態における凹凸の噛み合わせによる接合方式では、接着剤を用いて固定しておらず接着剤の成分が電解液内に混入することが回避される。また、活物質層の表面に接着剤が塗布されていると、接着領域ではイオンの移動が少なくとも部分的に妨げられ、実質的に活物質層同士の対向面積が減少するが、活物質層外にて凹凸の噛み合わせにより接合することで、このような不具合が回避される。   On the other hand, when a method of joining with an adhesive is used as a general unitization means, the components of the adhesive may be mixed in the electrolytic solution. In the joining method by engaging the concave and convex portions in the present embodiment, the components of the adhesive are avoided from being mixed in the electrolytic solution without being fixed by using the adhesive. Further, when an adhesive is applied to the surface of the active material layer, migration of ions is at least partially hindered in the adhesion region, and the facing area between the active material layers is substantially reduced. By joining by engaging the concave and convex portions, such a problem can be avoided.

また、熱融着により接合する方式とした場合には、温度にバラツキが生じやすく、品質安定の難易度が高い。実施形態における凹凸の噛み合わせによる接合方式では、セパレータと金属箔とを熱融着で固定しておらず温度のバラツキが生じることもなく品質を安定化させることができる。   Further, when the method of joining by heat fusion is adopted, variations in temperature are likely to occur, and the difficulty of stable quality is high. In the joining method by engaging the concavities and convexities in the embodiment, the separator and the metal foil are not fixed by heat fusion, and the quality can be stabilized without variation in temperature.

より詳しくは、袋状セパレータ４０で包まれた正極電極２０と、負極電極３０とを熱溶着によりユニット化する場合においては、熱源が必要となり、電極体（金属箔に活物質層が塗工されたもの）にも熱影響がでることが懸念される。本実施形態では、熱溶着としていた箇所を凹凸の噛み合わせにより接合することにより、金属箔３１と単層セパレータ４１，４２との接合時において、熱源が不要となる。熱溶着のための設備が不要にでき、その結果、原価の低減が図られる。また、熱溶着としていた箇所を凹凸の噛み合わせにより接合することにより、電極体において熱の影響を受けないようにすることができる。即ち、凹凸の噛み合わせにより接合することで熱源が不要の設備となり、原価低減及び熱影響を受け無くできる。   More specifically, when the positive electrode 20 wrapped with the bag-shaped separator 40 and the negative electrode 30 are unitized by heat welding, a heat source is required, and the electrode body (the active material layer is coated on the metal foil is coated). There is a concern that heat will also be generated. In the present embodiment, the heat-welded portions are joined together by the engagement of the concavities and convexities, so that a heat source is not required when joining the metal foil 31 and the single-layer separators 41 and 42. Equipment for heat welding can be dispensed with, resulting in cost reduction. In addition, by joining the portions that have been heat-welded together by engaging the concavities and convexities, it is possible to prevent the electrode body from being affected by heat. That is, by joining by engaging the concavities and convexities, a heat source is not required, and the cost can be reduced and the influence of heat can be eliminated.

さらに、セパレータとセパレータとを溶着することは容易であるがセパレータと金属箔を溶着することは難しいが、本実施形態では先に二枚の単層セパレータ４１，４２間を溶着しておき、その後に単層セパレータ４１，４２と金属箔３１とを凹凸の噛み合わせにより接合することができる。   Further, although it is easy to weld the separator and the separator, it is difficult to weld the separator and the metal foil, but in the present embodiment, the two single-layer separators 41 and 42 are welded first, and then In addition, the single-layer separators 41 and 42 and the metal foil 31 can be joined to each other by engaging the concave and convex portions.

また、負極電極３０の角部３３ａ，３３ｂ，３３ｃ，３３ｄを接合箇所とすべく活物質層非形成領域（未塗工部）３３を残し、当該領域と単層セパレータ４１，４２とを凹凸の噛み合わせによって一体化することにより、無駄に未塗工部を残すことによる材料費が無駄になることが回避される。   In addition, the active material layer non-formed region (uncoated portion) 33 is left so that the corners 33a, 33b, 33c, 33d of the negative electrode 30 are used as joint portions, and the region and the single-layer separators 41, 42 are made uneven. By integrating by meshing, it is possible to avoid waste of material cost due to waste of uncoated portions.

実施形態における凹凸の噛み合わせによる接合方式では、接合部５０は、凹凸による厚みの増加を伴うが、セパレータ４１と金属箔３１とセパレータ４２を重ねても活物質層２２，３２が無いのでユニットＵｎ全体として厚くなることはない。特に、本実施形態では、正極電極２０が袋状セパレータ４０で包まれた状態のユニットＵｎの接合箇所は、袋状セパレータ４０で正極電極２０を包む工程において形成時の熱融着により、他の部位よりも薄くなっている。このため、噛み合わせの深さを大きく取りやすい。さらに、矩形のユニットＵｎにおいて図４（ａ）に示すように対角方向に凹凸５１が延びているので剥がれ力Ｆ１，Ｆ２に対し剥がれが生じにくい。   In the joining method based on the engagement of the concavities and convexities in the embodiment, the joint portion 50 is accompanied by an increase in the thickness due to the concavities and convexities, but since the active material layers 22 and 32 are not provided even if the separator 41, the metal foil 31 and the separator 42 are stacked, the unit Un. It does not become thick as a whole. In particular, in the present embodiment, the joining point of the unit Un in the state where the positive electrode 20 is wrapped in the bag-shaped separator 40 is different from the other bonding portion due to heat fusion during formation in the step of wrapping the positive electrode 20 in the bag-shaped separator 40. It is thinner than the part. For this reason, it is easy to obtain a large engagement depth. Further, in the rectangular unit Un, the unevenness 51 extends diagonally as shown in FIG. 4A, and therefore peeling is less likely to occur against the peeling forces F1 and F2.

このように、凸凹の噛み合わせより接合する方式においては、袋状セパレータ４０（単層セパレータ４１，４２で包まれた正極電極２０の角部）と負極電極３０（金属箔３１）とを接合しており、接合用の熱源を不要にできる。   In this manner, in the method of joining by engaging the unevenness, the bag-shaped separator 40 (corner portion of the positive electrode 20 wrapped with the single-layer separators 41 and 42) and the negative electrode 30 (metal foil 31) are joined. Therefore, the heat source for joining can be eliminated.

上記実施形態によれば、以下のような効果を得ることができる。
（１）電極組立体の構成として、二枚のセパレータとしての二枚の単層セパレータ４１，４２間に正極電極２０が挟まれた積層体６０に負極電極３０が積層されている。二枚の単層セパレータ４１，４２における正極電極２０からはみ出る領域４３と負極電極３０の金属箔３１における活物質層３２が形成されていない活物質層非形成領域３３とが重なった部位６１に凹凸の噛み合わせにより接合された接合部５０を有する。よって、接着剤を用いて固定しておらず、例えば、接着剤の成分が電解液内に混入するといったことが回避され、性能に影響を出にくくすることができる。 According to the above embodiment, the following effects can be obtained.
(1) As the configuration of the electrode assembly, the negative electrode 30 is laminated on the laminated body 60 in which the positive electrode 20 is sandwiched between the two single-layer separators 41 and 42 as the two separators. Irregularities are formed on a portion 61 where the region 43 of the two single-layer separators 41 and 42 protruding from the positive electrode 20 and the active material layer non-forming region 33 of the metal foil 31 of the negative electrode 30 where the active material layer 32 is not formed overlap. It has the joint part 50 joined by the meshing of. Therefore, it is possible to prevent the components of the adhesive from being mixed in the electrolytic solution without being fixed by using the adhesive, and it is possible to prevent the performance from being adversely affected.

（２）接合部５０は、矩形状の二枚の単層セパレータ４１，４２の角部４３ａ，４３ｂ，４３ｃ，４３ｄ及び矩形状の負極電極３０の角部３３ａ，３３ｂ，３３ｃ，３３ｄに形成されている。つまり、凹凸の噛み合わせによる接合は、矩形状の二枚の単層セパレータ４１，４２の角部４３ａ，４３ｂ，４３ｃ，４３ｄ及び矩形状の負極電極３０の角部３３ａ，３３ｂ，３３ｃ，３３ｄで行われる。負極電極および正極電極の外周において、角部以外は接合代、例えば溶着代を考慮する必要が無いので、活物質層を可能な限り大きく取り、容量アップを図ることが出来る。   (2) The joint portion 50 is formed on the corner portions 43a, 43b, 43c, 43d of the two rectangular single-layer separators 41, 42 and the corner portions 33a, 33b, 33c, 33d of the rectangular negative electrode 30. ing. That is, the joining by the engagement of the unevenness is performed by the corner portions 43a, 43b, 43c, 43d of the two rectangular single-layer separators 41, 42 and the corner portions 33a, 33b, 33c, 33d of the rectangular negative electrode 30. Done. On the outer circumferences of the negative electrode and the positive electrode, it is not necessary to consider the bonding margin, for example, the welding margin except for the corners, so that the active material layer can be made as large as possible to increase the capacity.

（３）二枚の単層セパレータ４１，４２における接合部５０は溶着されている。つまり、二枚の単層セパレータ４１，４２間に正極電極２０が挟まれた状態において、二枚の単層セパレータ４１，４２における凹凸の噛み合わせによる接合予定領域は溶着されている。単層セパレータ４１，４２は多孔質の樹脂材料よりなる為、溶着によりその厚みは減少する。凹凸の噛み合わせにより固定する場合、噛み合わせされた領域の厚みが厚くなるが、単層セパレータ４１，４２の溶着部で噛み合わせを行うことで、厚みへの影響を軽減できる。   (3) The joint portion 50 of the two single-layer separators 41 and 42 is welded. That is, in the state where the positive electrode 20 is sandwiched between the two single-layer separators 41 and 42, the joining scheduled regions due to the engagement of the irregularities in the two single-layer separators 41 and 42 are welded. Since the single-layer separators 41 and 42 are made of a porous resin material, their thickness is reduced by welding. When fixing by the meshing of the unevenness, the thickness of the meshed region becomes thicker, but by meshing at the welded portions of the single-layer separators 41 and 42, the influence on the thickness can be reduced.

（４）凹凸５１は対角方向に延びているので、剥がれにくくできる。
（５）電極組立体の製造方法として、第１工程と第２工程とを有する。第１工程においては、二枚のセパレータとしての二枚の単層セパレータ４１，４２間に正極電極２０を挟んで積層するとともに、この積層体６０に負極電極３０を積層する。第２工程においては、第１工程後に、二枚の単層セパレータ４１，４２における正極電極２０からはみ出る領域４３と負極電極３０の金属箔３１における活物質層３２が形成されていない活物質層非形成領域３３とが重なった部位６１を、凹凸の噛み合わせにより接合する。これにより、上記（１）の電極組立体が製造される。 (4) Since the unevenness 51 extends diagonally, it is difficult to peel it off.
(5) The manufacturing method of the electrode assembly includes a first step and a second step. In the first step, the positive electrode 20 is sandwiched between the two single-layer separators 41 and 42 as the two separators, and the negative electrode 30 is stacked on the laminated body 60. In the second step, after the first step, the region 43 protruding from the positive electrode 20 in the two single-layer separators 41 and 42 and the active material layer 32 in the metal foil 31 of the negative electrode 30 where the active material layer 32 is not formed are not formed. The portion 61 where the formation region 33 overlaps is joined by meshing the concave and convex portions. As a result, the electrode assembly of (1) above is manufactured.

実施形態は前記に限定されるものではなく、例えば、次のように具体化してもよい。
○ 第１工程において、二枚の単層セパレータ４１，４２間に正極電極２０が挟まれた状態において、二枚の単層セパレータ４１，４２における凹凸の噛み合わせによる接合予定領域は溶着されていなくてもよい。この場合には単層セパレータ４１，４２間の接合を含めて熱溶着が不要となる。 The embodiment is not limited to the above, and may be embodied as follows, for example.
○ In the first step, in the state where the positive electrode 20 is sandwiched between the two single-layer separators 41 and 42, the joining scheduled region due to the engagement of the unevenness in the two single-layer separators 41 and 42 is not welded. You may. In this case, heat welding is not necessary including the joining between the single-layer separators 41 and 42.

○ 図４（ａ），（ｂ），（ｃ）においては複数の凹凸５１は、長方形状のユニットＵｎの対角方向に直交する方向において並設され、各凹凸５１は、長方形状のユニットＵｎの対角方向に延びていたが、これに代わり、図７のようにしてもよい。図７において、複数の凹凸５２は、長方形状のユニットＵｎの対角方向に並設され、各凹凸５２は、長方形状のユニットＵｎの対角方向に直交する方向に延びている。   In FIGS. 4A, 4B, and 4C, the plurality of unevennesses 51 are juxtaposed in a direction orthogonal to the diagonal direction of the rectangular unit Un, and each unevenness 51 is a rectangular unit Un. However, instead of this, the configuration shown in FIG. 7 may be used. In FIG. 7, a plurality of irregularities 52 are arranged side by side in a diagonal direction of the rectangular unit Un, and each irregularity 52 extends in a direction orthogonal to the diagonal direction of the rectangular unit Un.

○ 図１（ａ），（ｂ），（ｃ）に代わり、図８（ａ），（ｂ），（ｃ）に示すようにしてもよい。図８（ａ），（ｂ），（ｃ）において、電極組立体の構成として、二枚の単層セパレータ４１，４２と正極電極２０との積層体は２組有し、２組の積層体８０ａ，８０ｂの間に負極電極３０が挟まれている。   ○ Instead of FIG. 1(a), (b), (c), you may make it show in FIG. 8(a), (b), (c). 8(a), (b), and (c), as a structure of the electrode assembly, two single-layer separators 41 and 42 and a positive electrode 20 have two stacked bodies, and two stacked bodies. The negative electrode 30 is sandwiched between 80a and 80b.

接合部９０は、２組の積層体８０ａ，８０ｂでの二枚の単層セパレータ４１，４２における正極電極２０からはみ出る領域４３と負極電極３０の金属箔３１における活物質層３２が形成されていない活物質層非形成領域３３とが重なった部位に形成されている。二枚のセパレータにおける接合部８１は溶着されていても、いなくてもよい。   In the joining portion 90, the region 43 protruding from the positive electrode 20 in the two single-layer separators 41 and 42 in the two sets of the laminated bodies 80a and 80b and the active material layer 32 in the metal foil 31 of the negative electrode 30 are not formed. It is formed in a portion where the active material layer non-forming region 33 overlaps. The joint 81 in the two separators may or may not be welded.

電極組立体の製造方法として、第１工程と第２工程とを有する。第１工程においては、二枚の単層セパレータ４１，４２間に正極電極２０を挟んで積層した二組の積層体８０ａ，８０ｂの間に負極電極３０を積層する。第２工程においては、第１工程後に、二組の積層体８０ａ，８０ｂでの二枚の単層セパレータ４１，４２における正極電極２０からはみ出る領域４３と負極電極３０の金属箔３１における活物質層３２が形成されていない活物質層非形成領域３３とが重なった部位を、凹凸の噛み合わせにより接合する。   The manufacturing method of the electrode assembly includes a first step and a second step. In the first step, the negative electrode 30 is laminated between the two sets of laminated bodies 80a and 80b in which the positive electrode 20 is sandwiched between the two single-layer separators 41 and 42. In the second step, after the first step, the region 43 protruding from the positive electrode 20 in the two single-layer separators 41 and 42 in the two sets of the laminated bodies 80a and 80b and the active material layer in the metal foil 31 of the negative electrode 30. A portion where the active material layer non-forming region 33 where the 32 is not formed overlaps is joined by meshing of the unevenness.

電極組立体の全体構成としては、図８（ａ），（ｂ），（ｃ）に示すように、単層セパレータ４１，４２で包まれた正極電極２０と、負極電極３０と、単層セパレータ４１，４２で包まれた正極電極２０と、を重ねて接合したものに対し、負極電極３０を積層して一対とし、これを積層して構成する。よって、接着剤を用いて固定しておらず接着剤の成分が電解液内に混入することが回避され、性能に影響を出にくくすることができる。また、凹凸の噛合わせにより袋状セパレータ４０と負極電極３０の金属箔３１と袋状セパレータ４０とを接合しており、熱源を不要にできる。特に、先に正極電極２０を挟んだ単層セパレータ４１，４２同士を溶着しておき、２つの袋状セパレータ４０の間に負極電極３０を挟んだ状態で凹凸の噛み合わせにより接合するとセパレータと金属箔とを溶着によらずに接合することができる。   The overall structure of the electrode assembly is, as shown in FIGS. 8A, 8B, and 8C, a positive electrode 20 surrounded by single-layer separators 41 and 42, a negative electrode 30, and a single-layer separator. The positive electrode 20, which is wrapped with 41 and 42, is laminated and joined, and the negative electrode 30 is laminated to form a pair, which is laminated. Therefore, it is possible to prevent the components of the adhesive from being mixed in the electrolytic solution without being fixed by using the adhesive, and it is possible to prevent the performance from being adversely affected. Further, the bag-shaped separator 40, the metal foil 31 of the negative electrode 30 and the bag-shaped separator 40 are joined by the engagement of the irregularities, so that the heat source can be eliminated. In particular, when the single-layer separators 41 and 42 with the positive electrode 20 sandwiched therebetween are welded together and the negative electrode 30 is sandwiched between the two bag-shaped separators 40 and joined together by the concavo-convex engagement, the separator and the metal are separated. The foil can be joined without welding.

１０…電極組立体、２０…正極電極、２１…金属箔、２２…活物質層、３０…負極電極、３１…金属箔、３２…活物質層、３３…活物質層非形成領域、３３ａ…角部、３３ｂ…角部、３３ｃ…角部、３３ｄ…角部、４１…セパレータ、４２…セパレータ、４３…領域、４３ａ…角部、４３ｂ…角部、４３ｃ…角部、４３ｄ…角部、５０…接合部、６０…積層体、６１…部位、８０ａ…積層体、８０ｂ…積層体。
DESCRIPTION OF SYMBOLS 10... Electrode assembly, 20... Positive electrode, 21... Metal foil, 22... Active material layer, 30... Negative electrode, 31... Metal foil, 32... Active material layer, 33... Active material layer non-formation area, 33a... Corner Part, 33b... corner part, 33c... corner part, 33d... corner part, 41... separator, 42... separator, 43... area, 43a... corner part, 43b... corner part, 43c... corner part, 43d... corner part, 50 ... junction, 60... laminated body, 61... site|part, 80a... laminated body, 80b... laminated body.

Claims (7)

金属箔の少なくとも一方の面に活物質層が形成された複数枚の正極電極、及び、金属箔の少なくとも一方の面に活物質層が形成された複数枚の負極電極が、セパレータを介在させた状態で交互に積層された電極組立体であって、
二枚のセパレータ間に前記正極電極が挟まれた積層体に前記負極電極が積層され、前記二枚のセパレータにおける前記正極電極からはみ出る領域と負極電極の金属箔における前記活物質層が形成されていない活物質層非形成領域とが重なった部位に凹凸の噛み合わせにより接合された接合部を有することを特徴とする電極組立体。 A plurality of positive electrode electrodes having an active material layer formed on at least one surface of the metal foil, and a plurality of negative electrode electrodes having an active material layer formed on at least one surface of the metal foil with a separator interposed An electrode assembly that is alternately laminated in a state,
The negative electrode is laminated in a laminated body in which the positive electrode is sandwiched between two separators, and a region protruding from the positive electrode in the two separators and the active material layer in the metal foil of the negative electrode are formed. An electrode assembly having a joint portion joined by meshing of concave and convex portions in a portion where an active material layer non-forming region which does not exist is overlapped. 前記接合部は、矩形状の前記二枚のセパレータの角部及び矩形状の前記負極電極の角部に形成されていることを特徴とする請求項１に記載の電極組立体。   The electrode assembly according to claim 1, wherein the joining portion is formed at a corner portion of the two separators having a rectangular shape and a corner portion of the negative electrode having a rectangular shape. 前記二枚のセパレータと前記正極電極との積層体は２組有し、２組の積層体の間に前記負極電極が挟まれており、
前記接合部は、２組の積層体での前記二枚のセパレータにおける前記正極電極からはみ出る領域と負極電極の金属箔における前記活物質層が形成されていない活物質層非形成領域とが重なった部位に形成されていることを特徴とする請求項１または２に記載の電極組立体。 The laminate of the two separators and the positive electrode has two sets, and the negative electrode is sandwiched between the two sets of laminates,
In the joining portion, a region protruding from the positive electrode in the two separators in the two sets of laminated bodies and an active material layer non-forming region in which the active material layer is not formed in the metal foil of the negative electrode overlap. The electrode assembly according to claim 1 or 2, wherein the electrode assembly is formed in a portion. 前記二枚のセパレータにおける前記接合部は溶着されていることを特徴とする請求項１〜３のいずれか１項に記載の電極組立体。   The electrode assembly according to any one of claims 1 to 3, wherein the joint portion of the two separators is welded. 前記凹凸は対角方向に延びていることを特徴とする請求項２に記載の電極組立体。   The electrode assembly according to claim 2, wherein the unevenness extends diagonally. 金属箔の少なくとも一方の面に活物質層が形成された複数枚の正極電極、及び、金属箔の少なくとも一方の面に活物質層が形成された複数枚の負極電極が、セパレータを介在させた状態で交互に積層された電極組立体の製造方法であって、
二枚のセパレータ間に前記正極電極を挟んで積層するとともに、この積層体に前記負極電極を積層する第１工程と、
第１工程後に、前記二枚のセパレータにおける正極電極からはみ出る領域と負極電極の金属箔における活物質層が形成されていない活物質層非形成領域とが重なった部位を、凹凸の噛み合わせにより接合する第２工程と、
を有することを特徴とする電極組立体の製造方法。 A plurality of positive electrode electrodes having an active material layer formed on at least one surface of the metal foil, and a plurality of negative electrode electrodes having an active material layer formed on at least one surface of the metal foil with a separator interposed A method of manufacturing an electrode assembly that is alternately laminated in a state,
A first step of laminating the positive electrode between two separators, and laminating the negative electrode on the laminated body;
After the first step, the regions of the two separators protruding from the positive electrode and the regions of the metal foil of the negative electrode where the active material layer is not formed and where the active material layer is not formed overlap with each other, and are joined together by engaging and recessing irregularities. A second step of
A method for manufacturing an electrode assembly, comprising: 金属箔の少なくとも一方の面に活物質層が形成された複数枚の正極電極、及び、金属箔の少なくとも一方の面に活物質層が形成された複数枚の負極電極が、セパレータを介在させた状態で交互に積層された電極組立体の製造方法であって、
二枚のセパレータ間に前記正極電極を挟んで積層した二組の積層体の間に負極電極を積層する第１工程と、
第１工程後に、前記二組の積層体での前記二枚のセパレータにおける正極電極からはみ出る領域と負極電極の金属箔における活物質層が形成されていない活物質層非形成領域とが重なった部位を、凹凸の噛み合わせにより接合する第２工程と、
を有することを特徴とする電極組立体の製造方法。
A plurality of positive electrode electrodes having an active material layer formed on at least one surface of the metal foil, and a plurality of negative electrode electrodes having an active material layer formed on at least one surface of the metal foil with a separator interposed A method of manufacturing an electrode assembly that is alternately laminated in a state,
A first step of laminating a negative electrode between two sets of laminated bodies in which the positive electrode is sandwiched between two separators;
After the first step, a region where the region protruding from the positive electrode in the two separators in the two sets of the stacked body and the active material layer-unformed region in which the active material layer is not formed in the metal foil of the negative electrode overlap each other. And a second step of joining by the engagement of the unevenness,
A method for manufacturing an electrode assembly, comprising:
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