Improved performance of graphite coated by hard carbon of PTCDA sodium salt for lithium-ion batteries

Abstract

The graphite layers are combined with van der Waals forces. During the charging and discharging process, the graphite layer spacing changes, causing the graphite flakes to peel off and pulverize, resulting in unsatisfactory electrical cycle performance. In addition, lithium ions can only be inserted from the end surface of the graphite, Will inevitably cause the increase of lithium-ion diffusion resistance, and affect the battery rate performance. In this paper, a sodium salt of perylene tetracarboxylic acid dianhydride is used. By adjusting different coating modification processes, the graphite anode particles coated with sodium salt of perylene tetracarboxylic acid dianhydride are further calcined at high temperature to obtain a graphite-like structure The amorphous hard carbon-coated modified graphite anode material, through comparison, it is found that different thicknesses (9–40 nm) of organic carbon coating show different surface morphologies, which effectively improves the structural stability of the graphite anode material. Performance, and finally obtain more excellent capacity, cycle stability performance and rate performance.