A novel porous AC/Ni(OH)2 composite was prepared by a two-step hydrothermal method, which was used as an electrode for a supercapacitor for the first time with a specific capacitance of 1653.5 F/g at 1 A/g and a cycling stability of 90.2% after 3000 cycles. Moreover, there is a asymmetric supercapacitor (ASC) assembled by using AC/Ni(OH)2 and active carbon. On the condition of having a power density of 801.5 W kg-1 with the voltage window of 1.6 V, the ASC produces a high energy density of 38.58 W h kg-1, maintaining an outstanding cycling stability capacitance retention of 88.5% after 3000 cycles at current density of 8 A g-1. Therefore, AC/Ni(OH)2 electrode material helps to improve the performance of ASC devices and can be used as a potential electrode material for the development of energy storage devices in the future.