Electrochemical properties of poly(anthraquinonyl imide)s as high-capacity organic cathode materials for Li-ion batteries

Abstract

Redox-active organic materials are potential cathode materials for material-sustainable and environment-friendly Li-ion batteries. As is one of the most prominent features for organic compounds, isomerism has a significant influence on their properties. Herein, we synthesize two isomeric pairs of poly(anthraquinonyl imide)s (PAQIs) by a simple one-pot reaction, and investigate their electrochemical properties as Li-ion battery cathodes by cyclic voltammogram and galvanostatic discharge/charge cycling. The PAQI materials exhibit a high reversible capacity of 202 mAh g−1 and a stable cyclability with 80% capacity retention over 200 cycles, and a remarkable rate performance, suggesting a potential feasibility of these organic cathode materials for high-capacity Li-ion batteries. The discharge/charge potentials of these PAQIs are slightly lower than the monomers. A further comparison of these four PAQIs indicates the isomerism plays a significant role in the electrochemical performance of these organic electrode materials.