Alloy foil and preparation method thereof, current collector, negative pole piece, secondary battery and electric device

The invention provides an alloy foil and a preparation method thereof, a current collector, a negative pole piece, a secondary battery and an electric device, the alloy foil comprises an iron element, a nickel element and a copper element, and the mass ratio of the nickel element in the alloy foil is 30-60%. The alloy foil provided by the invention can improve the energy density and reliability of the secondary battery.