Electrochemical Capacitance Of Cobalt And Nickel (hydro) Oxides Prepared By Hydrothermal/solvothermal Method

It is important for people to go on studying and exploiting novel electrode materials. Now, many cheap and environmentally benign transition-metal oxides are known as excellent electrode materials for supercapacitors with charge-storage mechanisms based predominatly on pseudo-capacitance has attracted many interests. In this paper, cobalt and nickel (hydro) oxides were prepared by hydrothermal/solvothermal method, and the electrochemical performances were studied. At the same time, the electrode materials of predominan behaviour for supercapacitors were studied and exploited. Based on this information I put forward my purposes and researches in this filed:1. A layered Co₃O₄ was obtained by thermal decomposition of Co2(OH)2CO3 precursor prepared by using P123 as"soft"template under hydrothermal conditions. The results demonstrated that the layered Co₃O₄ obtained at 200°C had a good stability and cyclic performance.. The nucleus/carpacelike Co₃O₄ was prepared by using C6H5Na3O7 as"soft"template under hydrothermal conditions. The effects of concentration of reaction, hydrothermal time and the agglutinative temperature on the morphology of Co₃O₄ and the electrochemical performances were researched in our experment.2. Nickel oxide (NiO) hollow spheres were obtained by hydrothermal method assisted with citric acid (CA) as"soft"template. It revealed that CA plays a key role in process of forming hollow sphere structures. Electrochemical properties of NiO hollow spheres were examined showed that NiO calcined at 300oC had a higher specific capacitance. The honeycomblike nickel oxide was synthesized by the solvothermal method with N, N-dimethylformamide (DMF). The influences of synthetic conditions for the microstructure and electrochemical properties of NiO were investigated. We discussed the new nonaqueous method to exploit the electrode materials of predominant behaviour for supercapacitors.