Construction of nickel cobalt sulfide nanosheet arrays on carbon cloth for performance-enhanced supercapacitor

Materials featured with self-supported three-dimensional network,hierarchical pores and rich electrochemical active sites are considered as promising electrodes for pseudocapacitors.Herein,a novel strategy for the growth of nickel-cobalt bisulfide(Ni Co S)nanosheets arrays on carbon cloth(CC)as supercapacitor electrodes is reported,involving deposition of two-dimensional metal-organic framework(MOF)precursors on the CC skeletons,conversion of MOF into nickel-cobalt layered double-hydroxide by ion exchange process and formation of Ni Co S by a sulfidation treatment.The Ni Co S nanosheets with rough surface and porous structures are uniformly anchored on the CC skeletons.The unique architecture endows the composite(Ni Co S/CC)with abundant accessible active sites.Besides,robust electrical/mechanical joint between the nanosheets and the substrates is attained,leading to the improved electrochemical performance.Moreover,an asymmetric supercapacitor device is constructed by using Ni Co S/CC and activated carbon as a positive electrode and a negative electrode,respectively.The optimized device exhibits a high specific capacitance,large energy density and long cycle life.The Ni Co S/CC electrode with intriguing electrochemical properties and mechanical flexibility holds great prospect for next-generation wearable devices.