Surface Selenization of NiCo-Layered Double Hydroxide Nanosheets for High-Performance Supercapacitors
Mengdi Wang, Xingyu Liu, Xiang Wu
Abstract
Due to their unique spatial structures, layered double hydroxides (LDHs) have been considered as prospective electrode materials for supercapacitors. In this work, several NiCo-LDH materials are obtained via a facile selenization process. This can improve the conductivity and reduce the electrochemical impedance of the samples. The 0.4Se-NiCo-LDH materials deliver a specific capacitance of 1396 F/g at 1 A/g. The capacity retention rate can reach 91.38% after 10,000 cycles. In addition, using the prepared materials as a positive electrode, an asymmetric supercapacitor is constructed. It offers an energy density of 60 Wh/kg at a power density of 2700 W/kg, demonstrating that the synthesized samples possess promising applications in future flexible energy-storage systems.