▎ 摘　　要

NOVELTY - Sodium ion battery cathode artificial SEI film, comprises a current collector (3), cathode active material layer (1) and an artificial SEI film layer (2). The two sides of the current collector are symmetrically coated with the active material cathode. The artificial SEI film precursor slurry is uniformly deposited on the cathode of the active material layer by atomic layer deposition technology, and after being baked at a high temperature of 50-95 ℃, artificial SEI film precursor slurry will form a uniform and compact nano-functional artificial SEI film layer (2) on the cathode of the active material layer (1), and preparing the sodium ion battery cathode artificial SEI film. USE - Used as sodium ion battery cathode artificial SEI film. ADVANTAGE - The film: has low electronic conductivity and high sodium ion conductivity; can reduce the direct contact between the cathode active material and the electrolyte; reduces the irreversible loss of active sodium during the first charging process; improves the first Columbic efficiency of the battery; can reduce the internal resistance of the battery; and improves the utilization rate of active materials and energy density of the battery and thus reducing the cost of the battery. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: preparation of sodium ion battery cathode artificial SEI film; and odium ion battery. DESCRIPTION OF DRAWING(S) - The drawing shows a structural diagram of a sodium ion battery cathode an artificial SEI film. 1Cathode active material 2Artificial sei film layer 3Current collector