Abstract: Disclosed is a method for manufacturing a wound battery cell including the following steps covering and welding two metal sheets respectively onto the two conductive layers of a same composite current collector; after covering and welding the two metal sheets respectively onto the two conductive layers, cutting the two metal sheets respectively to form a plurality of metal sub-sheets, and then winding the metal sheets and the composite current collector together, such that each of the metal sub-sheets includes a stacking portion and a protruding portion, the stacking portion is configured to cover the conductive layer, and the protruding portion protrudes out of an edge of the tab portion; and welding the metal strip tab and all the protruding portions of the same composite current collector.

Abstract: A battery cell, comprising: a current collector assembly comprising a main body and current collector tabs, wherein the main body is provided with a connecting end surface, each current collector tab comprises a first portion and a second portion which are connected to each other, the first portion is connected to the connecting end surface, the second portion protrudes from the first portion in the thickness direction of the main body, and the first portion, the second portion and the main body together define a groove; and metal strip tabs each comprising a protruding portion, a connecting portion and a body portion, wherein the connecting portion is connected to the body portion and protrudes from the body portion in the thickness direction of the main body, and the protruding portion is connected to the connecting portion and protrudes from the connecting portion in the width direction of the main body.