Square lithium secondary battery

摘要

A square lithium secondary battery includes a wound body in which a collective sheet in which a positive electrode sheet and a negative electrode sheet overlap each other with a first separator interposed therebetween is wound while a second separator is put inside the collective sheet. An active material mixture layer on one or both surfaces of at least one of the positive electrode sheet and the negative electrode sheet includes a region with a plurality of openings and a region with no opening. At least a bent portion of the collective sheet is covered with the region with the plurality of openings.

主权项

1. A battery comprising:
a positive electrode sheet; a negative electrode sheet; and a separator interposed between the positive electrode sheet and the negative electrode sheet, wherein the positive electrode sheet comprises a positive electrode current collector and a layer comprising a positive electrode active material, wherein the layer comprising the positive electrode active material is provided on a surface of the positive electrode current collector, wherein the positive electrode sheet, the negative electrode sheet, and the separator are wound, so that each of the positive electrode sheet, the negative electrode sheet, and the separator includes a first bent portion, wherein the first bent portion of the positive electrode sheet includes a first region where the layer comprising the positive electrode active material is not provided, a second region where the layer comprising the positive electrode active material is not provided, and a third region where the layer comprising the positive electrode active material is provided, and wherein the third region is between the first region and the second region.