Studies On Electrochemical Capacitive Behavior Of RuO₂-based Composite Oxide Electrode Materials

The key to effect the performance of supercapacitor is the characteristics of electrode materials for supercapacitor,the purpose of research is focus on how to prepare electrode materials with high-energy density,high specific capacity and long cycle life. Based on pseudo-capacitive mechanism of charge storage reaction, Ruthenium oxide is an ideal electrode material of supercapacitor with high specific capacity and energy density,the CV curve in sulfuric acid is close to rectangle. However, some disadvatanges of ruthenium oxide such as cost, environmental pollution limit its wide application in the industry. The purpose of this dissertation is mainly based on adding the other metal oxide to form composite metal oxides.due to good properties of SnO₂ and TiO₂ , in this study we doped SnO₂ and TiO₂ to ruthenium oxide as electrode materials for supercapacitor with low cost ,high specific capacity, good stability.Different composition ratio mixed Ti/RuO₂-SnO₂ and Ti/RuO₂-TiO₂-SnO₂electrodes are prepared by thermal decomposition, and the crystalline structure,morphology and pseudo- capacitive characteristics are characterized by XRD,SEM and other electrochemical methods.The results shows there are no significant diffraction peaks of RuO₂ and SnO₂ even more added with TiO₂ because RuO₂ and SnO₂ form solid solution, the oxide surface morphology shows mud-?at cracking with an agglomerated structure.When the content of oxides added is higher ,the value of specific capataince is decreased.When the molar ratio of RuO₂ is 30%, the pseudo-capacitive characteristics of Ti/RuO₂-SnO₂ and Ti/RuO₂-TiO₂-SnO₂ compound oxide electrodes all possess high electrochemical reversibility. In the case of the same amount of RuO₂ ,the capacitive property of Ti/Ru_0.3Ti_0.7-xSn_xO₂ electrodes are better than Ti/Ru_0.3Sn_0.7O₂.We contrast the following electrodes with the same quality of active coating,Ti/Ru_0.3Ti_0.7-xSn_xO₂,Ti/Ru_0.3Sn_0.7O₂ and Ti/RuO₂,the resulst shows pseudo- capacitive characteristics of RuO₂-based composite oxide electrodes doping with SnO₂ and SnO₂+TiO₂ are worse than Ti/RuO₂ without other oxides,however the amount of RuO₂ is decreased.While the amount of RuO₂ are reduced, specific capataince of Ti/ Ru_0.3Ti_0.7-xSn_xO₂ do not remain proportional decrease .