Simple preparation of V-doped NiCo-LDH as cathode of high energy density supercapacitor

Abstract

One of the most promising cathode materials for supercapacitors is nickel-cobalt layered double hydroxide (NiCo-LDH). Doping atoms are widely used to solve the problems of poor electrical conductivity and structural defects of electrode materials. Vanadium (V) has received widespread attention due to its multiple oxidation states and low cost. In this article, we use one-step hydrothermal method to synthesize V-doped NiCo-LDH (V-NC1.5). By regulating the doping amount of V, 2V-NC1.5 exhibits superb specific capacitance of 1835 F g−1 at 1 A g−1. An asymmetric aqueous supercapacitor was assembled with 2V-NC1.5 and activated carbon. Its maximum energy density can reach 60.9 Wh kg−1 at 800 W kg−1 of power density. When the two units are connected in series, they can effectively power a white LED bulb and maintain its brightness for more than 30 min. This result provides a potential opportunity for the efficient deployment of innovative energy storage technologies in the coming years.