Abstract
Transition metal sulfides (TMSs) have been widely researched as promising electrode materials for super-capacitors because of their high theoretical capacitance and rich redox reactive sites. In this work, tremella-like core-shell Co_9S_8@NiCo_2S_4 heterogeneous nanosheets were directly grown on Nickel foamed (NF) through the hydrothermal+electrodeposition method to obtain a self-supporting electrode. Benefiting from its unique tremella-like structure, ultra-thin nanosheets, and the positive synergies between Co_9S_8 and NiCo_2S_4, the prepared Co_9S_8@NiCo_2S_4@NF electrode presents a high specific capacity of 513 C g~(-1) (specific capacitance -1026 F g~(-1)) at 1 A g~(-1) with superior rate capability (62.8% capacitance retention rate at 10 A g~(-1)). Furthermore, the fabricated Co_9S_8@NiCo_2S_4@NF//active carbon (AC) hybrid supercapacitor displays a high energy density of 30 Wh kg~(-1) at a power density of 731.8 W kg~(-1) and superior cycling stability. The results prove that the strategy of hydrothermal+electrodeposition is a very effective method for the preparation of energy storage and conversion materials with unique core-shell morphology.