Preparation of NiCo-LDHs@rGO composites with improved electrochemical performance by ammonia diffusion method under closed conditions

Abstract

Layered double hydroxides (LDHs) have been considered to be favorable pseudocapacitance electrodes due to their adjustable composition and low cost. The NiCo-LDHs@rGO (reduced graphene oxide) compositeswere prepared by the ammonia diffusion method. The conductivity of NiCo-LDHs was improved by composite rGO. When 30 mg of rGO was added, the specific capacitance reached 1920.5F/g at 1 A/g. When being assembled into an asymmetric two-electrode supercapacitor, an energy density of 50.5 Wh/kg was achieved at a power density of 900 W/kg. The NiCo-LDHs@rGO composite has significantly improved the electrochemical properties.