Electrochemical Capacitance Performance Of Composites Metal Oxides

In recent years, supercapacitors attract growing attention to the use of electrical energy storage systems because of higher specific power than batteries and higher specific energy than conventional capacitors, owing to the high capacitance of the electrodes materials. Considerable effort has been devoted to the development and characterization of new electrode materials with improved performance. For the reason, the redox supercapacitor, in which active species can be fast and reversibly oxidized or reduced at characteristic potentials, are under development. This thesis consists of four parts. The next section is the content of very part. The purpose of the first chapter is to survey the fundamental principles, characterizations and applications of supercapacitors, especially the recent progress of researches on supercapacitors using carbon, transition-metal oxide and conducting polymer as electrode materials and the study of all solid sate supercapacitors. Based on this information I put forward my purposes and researches to solve some existed questions. The second chapter shows the electrochemical capacitance performance of the composite of PANI and MnO₂ synthesized by chemical method in acide electrolyte. This chapter is divided into two parts. 1. The aniline was polymerized by chemical oxidation in (NH₄)₂S₂O₈ solution containing of MnO₂. The results of electrochemical test show that the favorable conducting polymer was coated onto MnO₂, this low-cost metal oxide could even stably work at the more spacious redox potentials in acid electrolytes. 2. The practical performance and stability of the composite electrode were examined by galvanostatic current charge-discharge cycling in varied concentration of H₂SO₄ with 0.5M Na₂SO₄. In the optimal condition, the electrochemical capacitance performed better...