The Study Of The Electrode Material Of Supercapacitor

The super-capacitor is a new type electrochemical energy storage device between the traditional dielectric capacitor and the battery. The super-capacitors can provide high energy density, high power density and have long cycle life and less pollution. Because of so many excellences, super-capacitors have wide applications in communication, electronic industry, railway system, aviation industry, spaceflight industry, military field and so on. So super-capacitors are paid a lot of attention by many countries and scientific research organizations. The studies on super-capacitor-s mainly focus on the preparation of the electrode materials. In this dissertation, the high specific exterior area active carbon and the nickel oxide and nickel hydroxide doped with CeO₂, Y₂O₃, CNT were prepared.1. The high specific exterior area active carbon was prepared from anthracite using microwave as the heat source, KOH as catalyst. The study indicated that when the mass ratio of the KOH and anthracite is 3:1, microwave radiate is 7 minutes, the single electrode specific capacitance of the active carbon reaches to 301 F/g. And after 100 circles the capacitance only reduces 4%. The effects of stuff category, microwave radiation time, the mass ratio of the KOH and anthracite to the specific capacitance of the active carbon and charge/discharge property were discussed.2. Ni(OH)₂ material was prepared by chemistry deposition, and doped with CeO₂, Y₂O₃, CNT according to the mass ratio, then obtain NiO by heat treatment. The electrochemical property of the NiO and the NiO doped with CeO₂, Y₂O₃,CNTwas compared. After doped with CeC^ Y2O3, the capacitance of the NiO has a large increase, when the doping mass of the CeC>2 or Y2O3 is 10% of the NiO, the capacitances respectively are 277.4F/g% 247.9F/g. The cycle life of the NiO also has a obvious improvement after doped with CeO2% Y2O3. After 100 cycles the two kinds super-capacitor's capacitance only respectively decrease 3.7%% 4.9%. Under the same test condition, the capacitance of the NiO material doped with CNT has a little increase but its resistance has a large decrease, when the doping mass of the CNT is 15% of the NiO, the resistance reduces to 104m Q.3. Ni(OH)2 material was prepared by chemistry deposition, and doped with CeO2^ CNT according to the mass ratio. The electrochemical performance of the Ni(OH)2 materials were studied. In the 6mol/L KOH solution, the capacitance of Ni(OH)2 doped with 8% of CeO2 is 744.4F/g and the capacitance of Ni(OH)2 doped with 6% of CNT is 753.3F/g. The Ni(OH)2/active carbon dissymmetrical supercapacitors has good charge/discharge property, but the capacitance decreases faster than pure Ni(OH)2. After 100 circles the capacitance of the two kinds supercapacirors respectively decrease 18.5%, 33.9%. When the CeO2 was doped, the ESR of the supercapacitor increases along with the increase of the weight percentage of the CeO2. However when the CNT was doped, the ESR has a large decrease. When the weight percentage of the CNT is 12% of the Ni(0H)2, the ESR of the supercapancitor reduces to 216 m Q.