Ultrathin porous nickel-cobalt hydroxide nanosheets for high-performance supercapacitor electrodes

In this work, ultrathin porous nickel-cobalt layered double hydroxide (Ni-Co LDH) hybrid nanosheets on metal nickel sheets are synthesized via a facile hydrothermal method without any adscititious surfactant. The fabricated Ni-Co LDH hybrid nanosheet-based electrodes for supercapacitors in aqueous electrolyte exhibit a significantly enhanced specific capacitance (2184 F g(-1) at 1 A g(-1)) and energy density (91.76 W h kg(-1) at 825.84 W kg(-1)) due to the pronounced synergistic effect between Ni2+ and Co2+. Meanwhile, the Ni-Co LDH hybrid nanosheets as electrode materials have excellent long-life cycling stability, retaining 88.5% of the initial capacitance after 2000 cycles. Thereby, the Ni-Co nanocomposites are promising electrode materials for high-energy-density long-life cycling supercapacitors.