▎ 摘　　要

NOVELTY - High-energy density sodium ion battery comprises an anode, a cathode and an electrolyte, where the active material of the cathode is rich in nano-pore canal, and the size of the nano pores is less than 0.4 nm hard carbon material. USE - High energy density sodium ion battery for use in an electric vehicle industry and renewable energy in a world. Can also be used for wind energy and solar energy. ADVANTAGE - The high energy density sodium ion battery is provided with rich nano-pore and orifice size less than 0.4 nm as hard carbon material cathode, so as to prevent the solvent sodium ion into the pore canal and inhibiting electrolyte decomposition in the first cycle process, optimizing the formation of the solid electrolyte membrane (SEI) and achieving the purpose of sieving the electrolyte solvent and sodium ion. DESCRIPTION OF DRAWING(S) - The drawing shows a scanning electron microscope (SEM) diagram of a hard carbon cathode material.