▎ 摘　　要

NOVELTY - Sodium ion battery coal-based hard carbon cathode material is claimed. The sodium ion battery coal-based hard carbon material crystal face distance d002 value is more than 0.2, preferably 0.364-0.384 nm. USE - The material is useful as a cathode material of a sodium ion battery. ADVANTAGE - The material: removes ash from coal but retains volatiles and heteroatoms e.g. nitrogen, oxygen and sulfur through deashing, which improves the safety of the material while taking its conductivity and has both high sodium storage capacity and first-time coulombic efficiency. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) preparing the sodium ion battery coal-based hard carbon cathode material comprising (a) crushing the raw material coal, sieving, placing in the deashing solution for processing, water washing to neutral, drying to obtain the carbon precursor and (b) performing high temperature carbonization to the carbon precursor under the protection of inert gas and programmed cooling to 15-30 degrees C to obtain the sodium ion battery coal-based hard carbon cathode material; (2) a negative pole piece of sodium ion battery comprising conductive agent, adhesive, current collector and the coal-based hard carbon material; and (3) a sodium ion battery comprising the negative pole piece.