Abstract: With coke powder as raw materials,coke powder activated carbons(CPAC) were prepared by pretreatment via HNO₃ and activated through dipping-calcined activation method by the modifier of KOH.The physical properties of the product were characterized by field emission scanning electron microscopy(SEM),X-ray diffraction(XRD).Nitrogen adsorption was used to characterize the BET surface area,pore structure and pore size distribution,and the influence on electrochemical properties under the different activated temperatures and time was investigated.The composite electrode materials of CPAC/Al-substituted Ni(OH)₂ were synthesized through the method of co-precipitation,and the electrochemical performances of CPAC/Al-substituted Ni(OH)₂ composite electrode materials were characterized by the constant current charge/discharge testing and cyclic voltammetry testing.The experimental results show that coke powder activated carbon electrode materials has the best electrochemical performance when the activation temperature is 800℃ and the activation time is 3 h.Under such conditions,the specific capacitance of the product achieves 211 F/g.CPAC-800℃-3 h/Al-substituted Ni(OH)₂ composite electrode materials have the trend to increase initially,but start to decrease with the increase of doping amount present of aluminium.The specific capacitance of composite material can reach 1173.6 F/g when the mass ratio of CPAC to nickel is 1:1 by maintaining the doping quantity of aluminium at 4%(mass fraction).The composite electrode material with the doping quantity of aluminium as 4% and the mass ratio of CPAC to nickel as 1:1 has the best electrochemical performance after the constant current charge/discharge and cyclic voltammetry tests.