Rare earth metal lanthanum-organic frameworks derived three-dimensional mesoporous interconnected carbon nanosheets for advanced energy storage

Abstract

Herein, a facile simultaneously activation and catalytic carbonization of the rare earth metal lanthanum-organic frameworks precursor strategy is developed to prepare a novel three-dimensional (3D) mesoporous interconnected carbon nanosheets (LMCN) with large surface area and high graphitization degree. During the synthesizing process, the ZnCl2 and FeCl3 act as activation and catalysis, respectively, to promote the formation of mesoporous carbon nanosheets with developed pores structure. The typical LMCN-1 prepared by high percentage of ZnCl2 and FeCl3 holds an interconnected mesoporous framework composed of ultrathin nanosheets and abundant porosity, displaying high specific capacitance of 251 F g−1 at a current density of 0.5 A g−1 and holding an excellent rate performance. Moreover, a symmetric supercapacitor assembled based on LMCN electrodes exhibits a prospective high energy density of 20.7 Wh kg−1 at a power density of 228 W kg−1 with a wide working voltage of 1.8 V in 0.5 M Na2SO4 aqueous solution, along with the suitable capacity retention of 90.7% after 10,000 cycles.