Current collector and preparation method thereof, electrode plate, secondary battery and electric device

The invention provides a current collector and a preparation method thereof, an electrode plate, a secondary battery and an electric device. The current collector comprises a coating area used for coating an active film layer and an empty foil area used for leading out current, the empty foil area is in contact with the coating area, the empty foil area and the coating area both comprise nickel elements, and the mass percentage of the nickel elements in the empty foil area is larger than the mass percentage of the nickel elements in the coating area. In the current collector, the mass percentage of the nickel element in the empty foil region is greater than the mass percentage of the nickel element in the coating region, so that the internal resistance of the current collector can be reduced, and the overflowing effect of the current collector is improved.