Mixing solvothermal synthesis nickel selenide on the surface of graphene for high-efficiency asymmetric supercapacitors

Nickel selenide nanoparticles uniformly supported on graphene nanosheets to form NiSe 2 /rGO composites were prepared via one-step mixing solvothermal method. The NiSe 2 /rGO composite possesses a high specific capacity of 137.7 mA h g −1 (1A g −1 ) and displays an excellent rate property. Moreover, there are NiSe 2 /rGO-20 as electrode materials assembling asymmetric supercapacitors, which manifests high energy density (33.13 Wh kg −1 ) at a power density (850 W kg −1 ) and the capacity can maintain of 80 % after 10,000 cycles. Therefore, NiSe 2 /rGO composite can be a potential candidate for high-efficiency asymmetric supercapacitors.