▎ 摘　　要

In this work, carbon-coated NiO nanoparticles supported on graphene (NiO@ C/graphene) have been synthesized by integrating an atomic layer deposition (ALD) technique with a simple acetylene decomposition method. Transmission electron microscopy, X-ray diffraction analysis, X-ray photoelectron spectroscopy and Raman results demonstrated that uniform carbon films were coated onto the surfaces of NiO nanoparticles supported on graphene. The electrochemical properties of the NiO@ C/graphene were then investigated. The results showed that the special design enabled synergistic effects from graphene and the carbon layer to improve the electrochemical capacitive properties of NiO. As a supercapacitor electrode, the 400-NiO@ C/graphene exhibits an initial specific capacitance of 408 F g(-1) (1838 F g(-1) for NiO) at 1 A g(-1) and 68% is retained at 50 A g(-1). After 2000 charge-discharge cycles, the specific capacitance improves the initial value of similar to 28% at a high current density of 10 A g(-1), suggesting a great potential for high performance supercapacitors.