The invention belongs to the field of all-
solid-state batteries, and relates to a preparation method of an all-
solid-state battery composite negative
electrode plate, the prepared negative
electrode plate and the preparation method, and the preparation method comprises the following steps: placing a
lithium alloy foil between a first
copper foil and a second
copper foil, and carrying out rolling treatment to obtain a
lithium-containing composite
current collector;
coating one side, deviating from the
lithium alloy foil, of the first
copper foil with a carbon-coated layer, and forming through holes in the first
copper foil and the carbon-coated layer to obtain a
porous carbon-coated composite
current collector; and
coating negative
electrode slurry on one side, deviating from the first
copper foil, of the
carbon coating layer by a wet method to obtain the all-
solid-state battery composite negative electrode plate. The lithium
alloy foil is arranged between the first
copper foil and the second copper foil for rolling treatment, the lithium source is pre-buried in the lithium-containing composite
current collector, the lithium source is more slowly and uniformly pre-lithiated after being coated with negative electrode
slurry through the through holes, and the
carbon coating layer can reduce the possibility of
side reaction caused by direct contact between
sulfide electrolyte and the first copper foil and the second copper foil. And the surface and the interior of the
pole piece are not easily damaged in the pre-lithiation process, so that the first efficiency of the battery is improved.