Hydrothermally synthesized binder-less ZnS/CdS on nickel foam as promising hybrid supercapacitor electrode materials

A binary composite of metal sulfides (MS) is directly synthesized on nickel foam through hydrothermal process, resulting in snow like nanosphere suitable for hybrid supercapacitors (HSCs). Herein, a ZnS/CdS binary composite has been grown directly on nickel foam using a simple hydrothermal method. The structural features, morphological characteristics and electrochemical performance of the composite are systematically investigated. Especially, the highest capacitance of 739-325 F/g at 1-10 A/g was attained with good rate performance. Moreover, a binder-less ZnS/CdS/NF composite achieved a high power of 5030 W/kg at 42 Wh/kg energy density by realizing an expanded voltage to 1.8 V with decent durability. Interestingly, a 92.84 % retention was noticed after 6500 cycles, which indicates high performance stability of the ZnS/CdS/NF||AC HSC. These outcomes reveal the promising prospect of all-metal sulfide utilization for next-generation energy storage devices.