KR-20260068005-A - WOUND ELECTRODE ASSEMBLY

KR20260068005AKR 20260068005 AKR20260068005 AKR 20260068005AKR-20260068005-A

Abstract

A wound electrode body having a positive electrode and a negative electrode wound in a flat shape with a separator interposed therebetween, a pair of flat sections facing each other with the center of the wound in between, and a pair of curved sections connecting the ends of the pair of flat sections, wherein the positive electrode comprises a first substrate in which a first metal foil and a first resin member are alternately bonded along the winding direction of the wound electrode body, and the negative electrode comprises a second substrate in which a second metal foil and a second resin member are alternately bonded along the winding direction, wherein in each of the pair of flat sections, the first metal foil and the second metal foil are alternately arranged in the direction in which the pair of flat sections face each other, and in each of the pair of curved sections, the first resin member and the second resin member are alternately arranged in the diameter direction of the wound electrode body.

Inventors

다테이시 미츠루
우에다 마사시
이즈미 준
마스오카 시즈카
사토 아야
가타야마 유지
야마모토 다츠야
마치다 게이타로

Assignees

도요타 지도샤（주）

Dates

Publication Date: 20260513
Application Date: 20251104
Priority Date: 20241106

Claims (7)

A wound electrode body having a positive electrode and a negative electrode wound in a flat shape with a separator interposed therebetween, a pair of flat sections facing each other with the center of the wound in between, and a pair of curved sections connecting the ends of the pair of flat sections. The above positive electrode comprises a first substrate in which a first metal foil and a first resin member are alternately bonded along the winding direction of the wound electrode body, and The above negative electrode comprises a second substrate in which a second metal foil and a second resin member are alternately bonded along the winding direction, and In each of the above pair of flat portions, the first metal foil and the second metal foil are alternately arranged in directions facing each other, and A wound electrode body in which, in each of the above pair of curved portions, the first resin member and the second resin member are alternately arranged in the diameter direction of the wound electrode body.
In Article 1, In a cross-section perpendicular to the winding axis of the above-mentioned wound electrode body, The first boundary, which is the boundary between the first metal foil and the first resin member, is located at the boundary between the pair of flat parts and the pair of curved parts, and A wound electrode body, wherein the second boundary, which is the boundary between the second metal foil and the second resin member, is located at the boundary between the pair of flat parts and the pair of curved parts.
In Article 2, In the cross section perpendicular to the above-mentioned winding axis, A wound electrode body in which, at each boundary of the pair of flat sections and the pair of curved sections, the first boundary and the second boundary are alternately arranged in parallel in an arrangement direction in which the first metal foil and the second metal foil are alternately arranged.
In Article 2, When the direction perpendicular to the opposing directions of the above-mentioned coil axis and the above-mentioned pair of flat parts is the width direction, In the cross section perpendicular to the above-mentioned winding axis, A wound electrode body in which the first boundary and the second boundary are alternately arranged at each boundary of the pair of flat sections and the pair of curved sections, such that they face inward in the width direction as they move from the outer circumference side to the inner circumference side of the wound electrode body.
In Article 2, When the direction perpendicular to the opposing directions of the above-mentioned coil axis and the above-mentioned pair of flat parts is the width direction, In the cross section perpendicular to the above-mentioned winding axis, A wound electrode body in which the first boundary and the second boundary are alternately arranged at each boundary of the pair of flat sections and the pair of curved sections, such that they face outward in the width direction as they move from the outer circumference side to the inner circumference side of the wound electrode body.
In any one of paragraphs 1 to 5, A wound electrode body in which the thickness of the first resin member is thinner than the first metal foil.
In Article 6, A wound electrode body in which the thickness of the second resin member is thinner than the second metal foil.

Description

Wound Electrode Assembly The present disclosure relates to a wound electrode body. As a conventional electrode body, Japanese Patent Publication No. 2016-042433 discloses a wound electrode body in which a separator is interposed between a positive electrode having a first metal foil and a positive electrode active material layer formed on the first metal foil, and a negative electrode having a negative electrode active material layer formed on the second metal foil, and said positive electrode and negative electrode are wound. In the wound electrode body, a pair of flat sections facing each other with the winding center in between, and a pair of curved sections connecting the ends of the pair of flat sections are formed. In the wound electrode, the pair of curved sections are maintained in a bent state, and a higher stress is applied to the pair of curved sections compared to the pair of flat sections. The present disclosure has been made in consideration of the above-mentioned problems, and the purpose of the present disclosure is to provide a wound electrode body capable of suppressing damage to the curved portion. A wound electrode body according to the present disclosure is a wound electrode body having a positive electrode and a negative electrode wound in a flat shape with a separator interposed therebetween, a pair of flat portions facing each other with the center of the wound in between, and a pair of curved portions connecting the ends of the pair of flat portions. In the wound electrode body, the positive electrode comprises a first substrate in which a first metal foil and a first resin member are alternately bonded along the winding direction of the wound electrode body. The negative electrode comprises a second substrate in which a second metal foil and a second resin member are alternately bonded along the winding direction. In each of the pair of flat portions, the first metal foil and the second metal foil are alternately arranged in the direction in which the pair of flat portions face each other. In each of the pair of curved portions, the first resin member and the second resin member are alternately arranged in the diameter direction of the wound electrode body. According to the above configuration, in each of the pair of curved sections, a first resin member and a second resin member are alternately arranged in the diameter direction of the wound electrode body, so that compared to a configuration in which a metal foil is arranged in the curved section, the curved section is more prone to bending deformation and less prone to breaking. As a result, even when high stress is applied to the curved section, damage to the curved section can be suppressed. In the wound electrode body according to the present disclosure, in a cross-section perpendicular to the winding axis of the wound electrode body, the first boundary, which is the boundary between the first metal foil and the first resin member, may be located at the boundary between the pair of flat portions and the pair of curved portions. The second boundary, which is the boundary between the second metal foil and the second resin member, may be located at the boundary between the pair of flat portions and the pair of curved portions. According to the above configuration, the entire curved portion is composed of a resin member. By doing so, damage to the curved portion can be further suppressed. In the wound electrode body according to the present disclosure, in the cross section perpendicular to the winding axis, at each boundary of the pair of flat portions and the pair of curved portions, the first boundary and the second boundary may be alternately arranged in a direction in which the first metal foil and the second metal foil are alternately arranged. In the above configuration as well, the entire curved portion is composed of a resin member. By doing so, damage to the curved portion can be further suppressed. In the wound electrode body according to the present disclosure, when the direction perpendicular to the direction in which the wound axis and the pair of flat parts face each other is the width direction, in the cross section perpendicular to the wound axis, at each boundary of the pair of flat parts and the pair of curved parts, the first boundary and the second boundary may be alternately arranged so as to face inward in the width direction as they move from the outer circumference side to the inner circumference side of the wound electrode body. According to the above configuration, the curved portion can be formed in a fan shape, making it easier for the curved portion to deform. As a result, when stress is applied to the curved portion, it is possible to prevent the curved portion from breaking. In the wound electrode body according to the present disclosure, when the direction perpendicular to the direction in which the wound axis and the pair of flat parts face each other is the width direction, in the cross section p