CN-122025846-A - Wound electrode body

CN122025846ACN 122025846 ACN122025846 ACN 122025846ACN-122025846-A

Abstract

The present invention relates to a wound electrode body in which a 1 st electrode and a2 nd electrode having a polarity different from that of the 1 st electrode are wound in a flat shape through a separator. In the wound electrode body, the 1 st electrode includes a resin base material, a conductive layer provided on a surface of the resin base material, and a 1 st active material layer provided on a main surface of the conductive layer on a side opposite to the side of the resin base material with respect to the conductive layer. The resin base material has higher heat dissipation properties in the portion located inside the wound electrode body than in the portion located outside the wound electrode body.

Inventors

TATEISHI TAKASHI
UEDA MASASHI
He Quanrun
Mashioka Shizuka
SATO REI
KATAYAMA YUJI
MACHIDA KEITARO
YAMAMOTO YASUNARI

Assignees

丰田自动车株式会社
丰田电池有限公司

Dates

Publication Date: 20260512
Application Date: 20251110
Priority Date: 20241111

Claims (7)

1. A wound electrode body in which a1 st electrode and a2 nd electrode having a polarity different from that of the 1 st electrode are wound in a flat shape through a separator, The 1 st electrode comprises a resin base material, a conductive layer provided on the surface of the resin base material, and a1 st active material layer provided on the main surface of the conductive layer on the opposite side of the resin base material to the conductive layer, The resin base material has a higher heat dissipation property in a portion located inside the wound electrode body than in a portion located outside the wound electrode body.
2. The rolled electrode body according to claim 1, The heat dissipation of the resin base material gradually or stepwise increases as it goes toward the inside of the wound electrode body.
3. The rolled electrode body according to claim 1, The resin base material is composed of a1 st resin member and a2 nd resin member having a heat dissipation property higher than that of the 1 st resin member, When the direction parallel to the winding axis of the wound electrode body is the width direction, the proportion of the 2 nd resin member in the width direction is larger than the proportion of the 1 st resin member in the width direction as the resin base material is directed toward the inside of the wound electrode body.
4. The rolled electrode body according to claim 1, The resin base material is formed by laminating a1 st resin member and a2 nd resin member having a heat dissipation property higher than that of the 1 st resin member, In the resin base material, the proportion of the 2 nd resin member in the thickness direction is larger than the proportion of the 1 st resin member in the thickness direction as it goes toward the inside of the wound electrode body.
5. The rolled electrode body according to claim 1, The resin base material includes an inner end portion located at one end of the wound electrode body in the winding direction and an outer end portion located at the other end of the wound electrode body in the winding direction, The resin base material is formed by joining a 1 st resin member located on the outer end side and a2 nd resin member located on the inner end side and having a heat dissipation property higher than that of the 1 st resin member, The proportion of the 2 nd resin member arranged along the winding direction is larger than the proportion of the 1 st resin member arranged along the winding direction.
6. The rolled electrode body according to claim 5, The 1 st resin member is joined in a state of biting into the 2 nd resin member in the winding direction.
7. The rolled electrode body according to any one of claim 3 to 6, The 2 nd resin member has self-extinguishing property.

Description

Wound electrode body Technical Field The present disclosure relates to a rolled electrode body. Background As a current collector used for a conventional wound electrode body, japanese patent application laid-open No. 2019-186195 discloses a structure in which an insulating layer and a conductive layer are provided and a plurality of through holes penetrating the insulating layer (resin foil) and the conductive layer are provided in the current collector. Disclosure of Invention When a sheet-like electrode having a conductive layer provided on the surface of a resin foil (resin base material) and an active material layer coated on the conductive layer is wound to form a wound electrode body, the resin foil has inferior heat dissipation properties compared with a metal foil, and therefore, heat tends to be trapped inside the winding in the wound electrode body. The present disclosure has been made in view of the above-described problems, and an object of the present disclosure is to provide a wound electrode body capable of improving heat radiation property inside a winding. The wound electrode body according to the present disclosure is a wound electrode body in which a1 st electrode and a2 nd electrode having a polarity different from that of the 1 st electrode are wound in a flat shape with a separator interposed therebetween. In the wound electrode body, the 1 st electrode includes a resin base material, a conductive layer provided on a surface of the resin base material, and a1 st active material layer provided on a main surface of the conductive layer on a side opposite to the side of the resin base material with respect to the conductive layer. The resin base material has a higher heat dissipation property in a portion located inside the wound electrode body than in a portion located outside the wound electrode body. According to the above configuration, the heat radiation performance of the portion of the resin base material located inside the wound electrode body can be improved by making the heat radiation performance higher than the heat radiation performance of the portion located outside the wound electrode body. In the wound electrode body according to the present disclosure, the heat dissipation of the resin base material may be gradually or stepwise increased as it goes toward the inside of the wound electrode body. According to the above configuration, the heat radiation property can be gradually or stepwise improved toward the inside of the wound electrode body. In the wound electrode body according to the present disclosure, the resin base material may be composed of a 1 st resin member and a2 nd resin member having a heat dissipation property higher than that of the 1 st resin member. When the direction parallel to the winding axis of the wound electrode body is the width direction, the proportion of the 2 nd resin member in the width direction may be larger than the proportion of the 1 st resin member in the width direction as the resin base material is directed inward of the wound electrode body. By adjusting the ratio of the 1 st resin member and the 2 nd resin member in the width direction of the resin base material in the above-described configuration, the heat radiation property inside the winding can be improved. In the wound electrode body according to the present disclosure, the resin base material may be formed by laminating a1 st resin member and a2 nd resin member having a heat dissipation property higher than that of the 1 st resin member. In the resin base material, the proportion of the 2 nd resin member in the thickness direction may be larger than the proportion of the 1 st resin member in the thickness direction as the resin base material is directed toward the inside of the wound electrode body. By adjusting the ratio of the 1 st resin member and the 2 nd resin member in the thickness direction of the resin base material in the above-described configuration, heat dissipation inside the winding can be improved. In the wound electrode body according to the present disclosure, the resin base material may include an inner end portion located at one end in the winding direction of the wound electrode body and an outer end portion located at the other end in the winding direction. The resin base material may be configured by joining a1 st resin member located on the outer end side and a2 nd resin member located on the inner end side and having a heat dissipation property higher than that of the 1 st resin member. The proportion of the 2 nd resin member arranged along the winding direction may be larger than the proportion of the 1 st resin member arranged along the winding direction. By adjusting the ratio of the 1 st resin member and the 2 nd resin member in the winding direction as described above, the heat dissipation property inside the winding can be improved. In the wound electrode body of the present disclosure, the 1 st resin member may be joined in a state of biting