The invention discloses a bipolar
current collector with double
copper layers and a preparation method thereof, and relates to the field of battery current collectors, the
current collector takes an
aluminum foil as a substrate, and a compact first
copper layer prepared by magnetron
sputtering and a thickened second
copper layer prepared by
electroplating are sequentially arranged on one side of the substrate. The first copper layer is prepared by adopting an intermittent deposition method, a pause interval is set in the
deposition process, and substrate heating and low-energy
ion beam bombardment are assisted, so that the compactness and the
bonding strength of a plating layer are remarkably improved; and the second copper layer is prepared by adopting a
pulse electroplating method, so that the non-porous and uniform structure is further ensured. Through a
sputtering and
electroplating composite process, a copper-aluminum interface which is high in
binding force and free of defects is successfully constructed,
electrolyte permeation is effectively blocked, and generation of
lithium-aluminum
alloy is prevented, so that the use safety of the bipolar
current collector is greatly improved, and the cycle life of a battery is greatly prolonged.