Ternary Co-Ni sulfides deposited on Co(OH)2 nanoflakes decorated carbon cloth as electrode for supercapacitor

Abstract

The modification of CC with Co(OH) 2 is employed to realize high utilization of Co-Ni-S. The as-prepared CC@Co(OH) 2 @Co-Ni-S exhibits enhanced specific capacitance compared to that of CC@Co-Ni-S without Co(OH) 2 modification. • A freestanding CC@Co(OH) 2 @Co-Ni-S electrode of supercapacitor is successfully constructed by two-step electrodeposition. • Carbon cloth is directly used as a current collector, without conductive additives or polymer binders. • The specific capacitance of CC@Co(OH) 2 @Co-Ni-S is greatly improved by the introduction of Co(OH) 2 nanosheets as substrate for Co-Ni-S. The ternary Co-Ni sulfides (Co-Ni-S) with earth-abundance, environmental friendliness, and high theoretical capacitance have been widely investigated in the field of pseudocapacitive supercapacitors. To further improve the utilization of Co-Ni-S to realize higher capacitance, Co-Ni-S was electrodeposited on carbon cloth (CC) that was modified by Co(OH) 2 nanoflakes (CC@Co(OH) 2 @Co-Ni-S). The modification of CC with Co(OH) 2 exhibits rough surface, which is beneficial to the electrodeposition of Co-Ni-S, further improving the electrochemical performance. As a result, the specific capacitance of CC@Co(OH) 2 @Co-Ni-S is higher than that of CC@Co-Ni-S without Co(OH) 2 modification. Even after 5000 cycles, the specific capacitance of CC@Co(OH) 2 @Co-Ni-S is still about 22% higher than that of CC@Co-Ni-S.