Rich Oxygen‐Containing Carbon Microparticles Derived from Self‐Assembled Polyimides for High‐Performance Supercapacitors

Abstract

Novel porous carbon microparticles derived from self‐assembled polyimides (PIs) were prepared via a facile solvothermal strategy, followed by thermally rearranged treatment and pyrolysis process. Without additional activation, the carbon microparticles exhibited large specific surface areas and abundant oxygen and nitrogen contents. Herein, the PIs microparticles derived from 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride and 3,3′‐diamino‐4,4′‐dihydroxybiphenyl, are self‐assembled by nanoscale layers. Due to thermally rearranged process, the as‐prepared carbon microparticles contain a large number of micropores and mesopores, resulting in large specific surface area of 1070.7 m2 g−1. Due to the rich oxygen of 10.96%, HPI‐90‐2‐900 offers higher specific capacitance of 263.7 F g−1 when the current density is 0.5 A g−1. In addition, the specific capacitances are maintained by 67.5% when the current density is enhanced to 10 A g−1. The long‐term stability test shows that the retention rate of specific capacitance is close to 100% after 10 000 cycles of charge and discharge when the current density was 1 A g−1, indicating a good cycle life. Moreover, a light‐emitting diode is successfully lighted up by the coin cells. Therefore, a facile strategy to improve the electrochemical performance of carbon microparticles to meet the requirements of energy storage and conversion is provided.