Controlled Preparation of Zn–Co–S Nanosheet Arrays for High-Performance All-Solid-State Supercapacitors

To develop new-generation all-solid-state hybrid supercapacitors (HSCs), bimetal sulfides are important electrode materials because of their superior electrochemical activity. A controlled self-sacrifice template strategy was explored to prepare a Zn–Co–S nanosheet array (NSA) as an electrode material. This controlled procedure contains three steps including the facile formation of a NSA on Ni foam (NF), the conversion of bimetal oxide by annealing in air, and the translation of bimetal sulfide through a S 2– anion-exchange reaction. A specific capacitance of 1904 F g –1 (952 C g –1 ) at 1 A g –1 is demonstrated by the Zn–Co–S NSA/NF. In addition, we incorporated the Zn–Co–S NSA/NF into a HSC and verified its excellent energy density and stability over 5000 cycles. This research provides a feasible strategy to rationally prepare bimetal sulfides for energy storage devices.