Self-supported sisal-like CuCo2O4@Ni(OH)2 core-shell composites grown on Ni foam for high-performance all-solid state supercapacitors

Construction of reasonable nanostructures for use as electrode materials is regarded as one critical strategy for improving the specific capacitance and cycle life of supercapacitors (SCs). In this reported study, self-supported, sisal-like CuCo2O4@Ni(OH)2 composites were successfully synthesized on Ni foam using a hydrothermal treatment followed by electrochemical deposition reaction. SEM characterization of the composites verified that the sisal-like CuCo2O4@Ni(OH)2 core-shell nanostructure were comprised of coating CuCo2O4 nanoneedles with Ni(OH)2 nano-flakes. This novel structure afforded the CuCo2O4@Ni(OH)2 composites a markedly enhanced specific capacitance of 1902 F g-1 at 2A g-1 and an ultra-long cycle life with a captaincy retention of 87.6% after 50000 cycles at 10 A g-1. Furthermore, activated carbon (AC) with low cost and high electrochemical activity was selected to prepare negative materials of SCs, then an asymmetric solid-state supercapacitor (ASSC) comprised of CuCo2O4@Ni(OH)2//AC was ass...