▎ 摘　　要

NOVELTY - Preparation method of hard carbon/soft carbon/graphite ternary composite carbon material, comprises mixing graphite, soft carbon precursor and hard carbon precursor powder evenly according to the mass ratio of 100:(3-36):(3-36), and calcining in an inert gas atmosphere at 500-1700℃ for 0.5-10 hours to obtain a hard carbon/soft carbon/graphite ternary composite carbon material. USE - The method is used for preparation of hard carbon/soft carbon/graphite ternary composite carbon material which is used in the negative electrode of potassium ion battery (all claimed). ADVANTAGE - Compared with traditional graphite negative electrode materials for potassium ion batteries, the method can obtain hard carbon/soft carbon/graphite ternary composite carbon negative electrode materials without further purification treatment, can increase the transmission speed of potassium ions, and buffer the volume change caused by the intercalation/extraction of potassium ions, and improve its cycle stability. The use of hard carbon coating can reduce the graphitization structure of soft carbon, shorten the length of graphene sheets, and increase the diffusion rate of potassium ions in soft carbon. The constructed hard carbon/soft carbon/graphite ternary composite carbon anode material improves its reversible capacity and cycle stability for potassium storage. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a hard carbon/soft carbon/graphite ternary composite carbon material prepared by the above method.