▎ 摘　　要

NOVELTY - Lithium/silicon/carbon composite cathode, is claimed. The lithium/silicon/carbon composite cathode is composite of ultra-thin lithium with lithium hexafluorophosphate (LiPF6) on the surface in situ and the substrate infiltrated with oxygen heterocyclic monomer solution through in situ polymerization, and the substrate include graphite/silicon oxide composite material, conductive additive, and binder. USE - The lithium/silicon/carbon composite cathode is useful in lithium ion battery (claimed). ADVANTAGE - The lithium/silicon/carbon composite cathode: improves the uniformity and structural stability of lithium deposition on the cathode; improves the cycle performance of the battery; has good adhesion and filling properties; makes the contact between lithium and the substrate more closely; reduces the porosity; evenly distribute the electric field at the interface; at the same time can effectively conduct lithium ions; promotes the reaction between metal lithium and the substrate; accelerates the integration of cathode; improves the lithiation efficiency of the substrate; and reduces the generation of dead lithium. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: preparing lithium/silicon/carbon composite cathode comprising (S1) dip-coating fluoride solution on the ultrathin lithium surface in a closed container under an inert atmosphere, carrying out fluorination of ultrathin lithium surfaces by in situ chemical reactions to generate uniform lithium fluoride (LiF) layers, then placing the metal lithium after surface fluorination under a dry inert atmosphere, and passing through gaseous phosphorus pentafluoride, carrying out chemical reaction between lithium fluoride and phosphorus pentafluoride, and uniformly forming lithium hexafluorophosphate on the ultrathin lithium surface, (S2) grinding and mixing graphite/silicon oxide composite material, conductive additive, binder and solvent, coating on the surface of current collector, and drying to obtain base material, (S3) soaking the base material in the solution of the oxygen heterocyclic monomer, and taking out after fully soaking, (S4) compacting the ultra-thin lithium surface-modified with lithium hexafluorophosphate obtained in step (S1) and the substrate of the wetting monomer solution obtained in step (S3), and allowing to stand at room temperature to obtain lithium/silicon/carbon composite cathode with interfacial in-situ polymerization; and lithium ion battery, comprising anode, cathode, diaphragm, and electrolyte, where the cathode is lithium/silicon/carbon composite cathode, and further the anode does not contain lithium, and the lithium-free anode is sulfur element (S), selenium element (Se), sulfur selenium compound (SexSy), iron sulfide (FexSy), titanium disulfide (TiS2), molybdenum disulfide (MoS2), manganese dioxide (MnO2), vanadium pentoxide (V2O5).