Cathodic deposition of interlaced nanosheet-like cobalt sulfide films for high-performance supercapacitors

In this study, an interlaced nanosheet-like cobalt sulfide (CoS) electroactive material was deposited on a Ni foam substrate using a facile and efficient electrochemical route and employed as a high-performance supercapacitor for the first time. An impressive specific capacitance, as high as 1471 F g−1 at 4 A g−1, was achieved for the interlaced nanosheet-like CoS electroactive material in 1.0 M KOH aqueous electrolyte. It delivered a remarkable specific capacitance of up to 1306 F g−1 even at a high charge–discharge current density of 40 A g−1, indicating its excellent energy storage at high rates. Moreover, nearly 100% retention of specific capacitance and >99% Coulombic efficiency were achieved even after consecutive 1000 cycles with a fairly high current density of 8 A g−1.