▎ 摘　　要

NOVELTY - Hard carbon composite material, comprises 80-120 pts. wt. porous carbon powder and 1-10 pts. wt. carbon material. The precursor of porous carbon powder includes microporous activated carbon, hierarchical porous activated carbon, template porous carbon, and/or porous graphene. The carbon material includes acetonitrile, n-butylamine, thiol, thioether, phosphate, and/or ethyl methyl hypophosphite. USE - The hard carbon composite material is useful in sodium ion batteries (claimed). ADVANTAGE - The material: is convenient to the transmission of sodium ions from the electrolyte; has high utilization rate; can avoid excessive sodium consumption due to unstable SEI film and modify the defects on the surface of porous carbon; reduce the contact area between the electrode and electrolyte and interface impedance; solves the problem of excessive decomposition of electrolyte; and ensure the high coulombic efficiency and cycle stability. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a preparation method of hard carbon composite material.