▎ 摘　　要

With the ever-increasing energy problem, people are paying more and more attention to green and safe energy. The preparation of a single electric double-layer capacitor or pseudocapacitance characteristic material into a composite material will improve the disadvantages of a single capacitor. In addition, Co doping is considered to be an effective method to improve material conductivity and energy conversion. In this paper, based on nickel hydroxide (Ni(OH)(2)) and reduced graphene oxide (RGO), Ni(OH)(2)/RGO and Co-doped Ni(OH)(2)/RGO were prepared by a one-step hydrothermal synthesis method. Their electrochemical performance and practicality have been studied. It is found that the Co-doped Ni(OH)(2)/RGO nanosheets have an initial specific capacitance of 2006 F g(-1) at a current density of 1 A g(-1) and a retention rate of 80.60% after 1000 cycles. Compared with Ni(OH)(2)/RGO composite material, it has been greatly improved. It shows that the addition of Co element has greatly improved the specific capacitance of the material, which provides a new idea for the future research of nickel-based electric double-layer capacitor materials.