Current collector, electrode sheet, secondary battery, electric device, copper foil, and preparation method for copper foil

Abstract

A current collector, an electrode sheet, a secondary battery, an electric device, a copper foil, and a preparation method for the copper foil are described. The current collector comprises the copper foil, the average particle size of the crystal grains in the copper foil ranges from 50 nm to 400 nm, and based on the total number of crystal grains in the copper foil, the proportion of the crystal grains of nano twin crystals is greater than or equal to 60%. The combination of the high proportion nano twin crystal structure and the small crystal grain size functions to improve the mechanical strength of the current collector while maintaining the high plasticity of the current collector, thereby providing a material basis for further improvement of the energy density and safety of the battery.

Dependencies are inferred from the claim text.