Graphene composite 3,4,9,10-perylenetetracarboxylic sodium salts with a honeycomb structure as a high performance anode material for lithium ion batteries

Abstract

In order to address the issues of high solubility in electrolytes, poor conductivity and low active site utilization of organic carbonyl electrode materials, in this work, the 3,4,9,10-perylenetetracarboxylic sodium salt (PTCDA-Na) and its graphene composite PTCDA-Na-G are prepared by the hydrolysis of 3,4,9,10-perylenetetracarboxylic dianhydride and the strategy of antisolvent precipitation. The obtained PTCDA-Na active substance has a porous honeycomb structure, showing a large specific surface area. Moreover, after recombination with graphene, the dispersion and specific surface area of PTCDA-Na are further enhanced, and more active sites are exposed and conductivity is improved. As a result, the PTCDA-Na-G composite electrode materials exhibit superior electrochemical energy storage behaviors. The initial charge capacity of the PTCDA-Na-G electrode is 890.5 mA h g⁻¹, and after 200 cycles, the capacity can still remain at 840.0 mA h g⁻¹ with a high retention rate of 94.3%, which is much larger than those of the PTCDA-Na electrode. In addition, at different current densities, the PTCDA-Na-G electrode also presents higher capacities and better cycle stability than the PTCDA-Na electrode. Compared with PTCDA-Na with a porous honeycomb structure and previously reported sodium carboxylic acid salts with a large size bulk structure, the PTCDA-Na-G composite material prepared in this work shows superior electrochemical energy storage properties due to its large specific surface area, high dispersion, more exposed active sites and large electrical conductivity, which would provide new ideas for the development of high performance organic electrode materials for lithium-ion batteries.