The purpose of this paper is to show how to obtain a supercapacitor with high specific power (P) and high specific energy (Ep) simultaneously.
The carbon aerogels are obtained by ambient pressure drying method instead of supercritical drying method and carbon aerogels/Ni(OH)2 composites are prepared by in situ polymerisation. A series of asymmetric supercapacitors based on carbon aerogels/Ni(OH)2 composites as positive electrode and activated carbon as negative electrode, respectively, are assembled. The electrochemical performances of carbon aerogels/Ni(OH)2 composites and supercapacitors are studied.
The results show that the specific capacitance (CP) of carbon aerogels/Ni(OH)2 composites is 584 F/m2. The working potential of supercapacitors could be increased to 1.6V. When the mass ratio of carbon aerogels and Ni(OH)2 is 3:7, the mass ratio of positive electrode and negative electrode is 1:1, the EP and P of the supercapacitor is higher than 10.5 Wh/kg and 578 W/kg, respectively, when the current varies from 50 mA to 100 mA and the attenuation ratio of CP is only 8.3 per cent after 10,000 cycles at 100 mA.
The supercapacitors can be used in the field of automobile engineering and can solve the problems of energy shortage and environmental pollutions.
The supercapacitor based on carbon aerogels/Ni(OH)2 composites as positive electrode and activated carbon as negative electrode is novel and the synthetic properties of the supercapacitor are excellent.
