Winding electrode

Abstract

To provide a wound electrode body that can suppress winding loosening. [Solution] The wound electrode body is a wound electrode body in which a first electrode 11 and a second electrode 12 having a different polarity from the first electrode 11 are wound in a flattened shape with a separator in between. The wound electrode body comprises a first resin member 110 wound around a winding axis and a second resin member 120 wound inside the first resin member 110 and along the first resin member 110 around the winding axis. The coefficient of linear expansion of the first resin member 110 is greater than the coefficient of linear expansion of the second resin member 120.

Claims

1. A wound electrode body in which a first electrode and a second electrode having a different polarity from the first electrode are wound in a flattened shape via a separator, A first resin member wound around a winding shaft, The first resin member comprises a second resin member wound inside the first resin member around the winding shaft along the first resin member, A wound electrode body wherein the coefficient of linear expansion of the first resin member is greater than the coefficient of linear expansion of the second resin member.

2. The first electrode includes a first substrate having a first resin member and a first conductive layer formed on the first resin member, and a first active material layer formed on the first conductive layer. The wound electrode body according to claim 1, wherein the second electrode comprises a second resin member and a second conductive layer formed on the second resin member, and a second active material layer formed on the second conductive layer.

3. The wound electrode body according to claim 1, wherein the first electrode includes a resin substrate on which the first resin member and the second resin member are laminated, a first substrate having a first conductive layer formed on the resin substrate, and a first active material layer formed on the first conductive layer.

4. The resin substrate has, in the lamination direction in which the first resin member and the second resin member are laminated, an overlapping region that overlaps with the first active material layer and a non-overlapping region that does not overlap with the first active material layer. The wound electrode body according to claim 3, wherein the proportion of the second resin member in the stacking direction in the overlapping region is greater than the proportion of the second resin member shown in the stacking direction in the non-overlapping region.

5. The first resin member contains polyethylene, The wound electrode body according to any one of claims 1 to 4, wherein the second resin member comprises polypropylene.

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