Hybrid supercapacitors based on polyaniline and activated carbon composite electrode materials

Purpose - The purpose of this paper is to develop feasible composite electrodes with a long cycle life and large specific capacitance and to investigate optimal ratio between aniline and activated carbon materials. Design/methodology/approach - PANI/AC composite electrode materials were synthesised by in situ polymerisation of aniline on activated carbon with ammonium persulphate as oxidant. Hybrid supercapacitors are assembled by putting Ni-MH battery separator between positive and negative electrodes. The electrochemical performances of PANI/AC composite electrode materials and supercapacitors are studied. Findings - The results show that the optimal ratio between aniline and activated carbon is 1:1.08. The specific capacitance of polyaniline electrode materials is 956 F g(-1). The specific capacitance of supercapacitors is 159.37 F g(-1). This result could be attributed to the pseudocapacitive effect of Ni(OH)(2). What's more, the activated carbon addition reduced the resistance of polymer electrode materials thus improving the cyclic life. Research limitations/implications - The supercapacitors can be used in the field of automobiles and can solve the problems of energy shortage and environmental pollutions. Originality/value - A hybrid supercapacitor, which was immersed in alkaline solution, was assembled by putting Ni-MH battery separator between two electrodes Ni(OH)2 as positive electrode and polyaniline composites as negative electrode. In the case of alkaline solution, the capacitive performance of hybrid supercapacitor was improved and excellent.