Tubular-like NiS/Mo2S3 microspheres as electrode material for high-energy and long-life asymmetric supercapacitors

Abstract

The tubular-like NiS/Mo 2 S 3 microspheres as electrode material are designed and synthesized by solvothermal method, and match with activated carbon to build a new asymmetric supercapacitor, improving specific energy and cycle life of asymmetric supercapacitors. The NiS/Mo 2 S 3 composite material of tubular-like microspheres possesses excellent specific capacity (199 mAh g −1 at a current density of 1 A g –1 ) and long cycle life (76% of initial capacity after 3000 cycles). In addition, a new asymmetric supercapacitor (ASC) based on NiS/Mo 2 S 3 (positive electrode) and AC (negative electrode) is fabricated, which have high energy storage and excellent cycle stability. The NiS/Mo 2 S 3 -2//AC ASC possesses high specific energy (31.2 Wh Kg −1 ) and specific power (850 W Kg −1 ), its specific capacity still maintains 81.3% after 10,000 cycles. Therefore, the tubular-like NiS/Mo 2 S 3 microspheres may enrich the material system related to nickel-molybdenum bimetal for SCs. The Tubular-like NiS/Mo 2 S 3 microspheres were synthesized by the two-step solvothermal method and matched with activated carbon materials. The designed asymmetric supercapacitor possesses high specific energy and power and a long-term cycling lifespan. Therefore, the performance of asymmetric supercapacitors proves that controlling the morphology can play a key role in energy storage devices. • Tubular-like NiS/Mo 2 S 3 microspheres is prepared by a simple two-step method. • The tubular-like NiS/Mo 2 S 3 microspheres shows a particle aggregation structure and has an excellent specific capacity. • Pioneering synthesis of a new structure of Ni/Mo bimetallic compound. • The ASCs device exhibits high specific energy.