Cracked bark-inspired ternary metallic sulfide (NiCoMnS4) nanostructure on carbon cloth for high-performance aqueous asymmetric supercapacitors

Abstract

In this paper, we report a high-performance self-supported supercapacitor electrode composed of a cracked bark-shaped Ni-Co-Mn ternary metallic sulfide (NiCoMnS4) nanostructure on carbon cloth prepared by a simple one-step hydrothermal process and subsequent electrochemical treatment. The electrode delivers a high specific discharge capacity of up to 2470.4 F g−1 at 1 A g−1 and high rate performances of 1635.6 F g−1 at 10 A g−1 and 910.2 F g−1 even at 32 A g−1. Cycling tests indicate that NiCoMnS4 could maintain >91.1% of its initial capacity and nearly 100% Coulombic efficiency over 10,000 cycles at 8 A g−1. An aqueous asymmetric supercapacitor assembled with NiCoMnS4 as the cathode, activated carbon as the anode, and 1 mol L−1 KOH as the electrolyte delivers an energy density of 68.2 W h kg−1 at 850.1 W kg−1 and capacity retention of 92.5% after 10,000 cycles at 4 A g−1. Given the excellent performance and simple material preparation of our proposed device, this study provides a valuable foundation for the development of self-supported metallic sulfide based electrodes with high electrochemical properties for potential application in aqueous asymmetric supercapacitors.