Self-Supported Ni0.85Se Nanosheets Array on Carbon Fiber Cloth for a High-Performance Asymmetric Supercapacitor

In this work, Ni0.85Se nanosheets array electrode material was prepared with carbon fiber cloth (CFC) as a substrate. Owing to their special structure, the Ni0.85Se nanosheets array exhibits an outstanding energy storage property with a superior specific capacitance (820F/g) and great rate capability (83.17%). Moreover, the Ni0.85Se electrode presents an great cycling performance with 82.63% retention after 10,000 cycles. The asymmetric supercapacitor (ASC) was fabricated based on Ni0.85Se positive and activated carbon (AC) negative electrode materials, with KOH/PVA gel as the electrolyte, respectively. A highest energy density of 29 Whkg(-1) was achieved at a power density of 779 Wkg(-1) under the optimal potential range of 1.6V. Furthermore, the Ni0.85Se//AC ASC devices demonstrate a great cycling performance of 81.25% capacitance retention after 5000 charge-discharge cycles. These excellent performance provide strong evidence to confirm the conclusion that Ni-0.85 Se nanosheets array used as electrode materials in supercapacitors and Ni-0.85 Se//AC asymmetric supercapacitors hold significant potential in the field of energy storage.