▎ 摘　　要

NOVELTY - Composite current collector, comprises a high molecular film (1) and a multi-layer conductive layer, where the multi-layer conductive layer (2) is arranged on the surface of the high molecular film; the high molecular film comprises a high molecular main body material and a flexible material in a ratio of 1: 0.1-0.2. USE - Composite current collector e.g. copper current collector and aluminum current collector, for use in lithium-ion battery. ADVANTAGE - The toughness material with strong toughness is doped into the high molecular film so as to improve the whole toughness of the product. The internal stress of the internal expansion of the battery is absorbed, and the stability of battery interface is ensured. The safety of battery and the related service life are improved. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a preparation method of the composite current collector comprising the following steps: (S1) adding toughness material in the polymer main body material to carry out doping modification, where the mass ratio of the polymer main body material and the toughness material is 1: 0.1-0.2; (S2) subjecting the particles after doping for casting operation, after forming film, biaxially orienting the film to form high molecular film, cutting and rolling operation; (S3) respectively performing conductive material atom deposition operation on the upper and lower surfaces of the polymer film, forming a multilayer conductive layer on the surface of the polymer film, where the thickness of the multilayer conductive layer is 0.5 3 µm; and (S4) cutting and rolling. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of a composite current collector. 1High molecular film 2Multi-layer conductive layer