The invention discloses a
solid-state
lithium battery composite negative
electrode, which comprises a negative
electrode current collector, a negative
electrode elastic-plastic body and a negative electrode
lithium metal which are sequentially stacked and connected, wherein the negative electrode elastic-plastic body takes a three-dimensional space structure coated with an
organic polymer as a container, the interior of the container is provided with an island-bridge three-dimensional interlaced porous structure which takes an active material
lithium titanate and the like as an island and takes an electric conduction and heat conduction material
carbon black and the like as a bridge, the negative electrode elastic-plastic body is tightly bonded with the
current collector and the
lithium metal, and the
lithium metal is embedded into the dried negative electrode elastic-plastic body through
hot pressing to form a composite negative electrode with a
layered structure. The invention also discloses a
solid-state battery adopting the composite negative electrode, and a preparation method of the
solid-state battery, wherein a three-dimensional porous disordered island-bridge frame structure of a negative
electrode material is constructed through a negative electrode elastic-plastic body, so that the
mechanical strength of the negative
electrode material is improved, the volume changeof the negative
electrode material during charging and discharging is absorbed and buffered, the growth of lithium dendrites is inhibited, the overall performance of the solid-state battery is improved, and the manufacturing cost is reduced.