Preparation And Electrochemical Performance Of Plural Oxide Containing With IrO₂（RuO₂）

The performance of super capacitor is mainly determined by the electrode.The design of electrode material could well be the biggest challenge to improve the capacity performance may face.Precious metal oxide RuO₂ and IrO₂ complete energy storage through its oxidation-reduction,has a high pseudocapacitance theoretically.RuO₂ and IrO₂ possesses metallic conductivity and excellent resistance to acid and alkali corrosion,is an excellent capacitive energy storage material and also will be the research emphasis of electrochemical industry.Reports on the organizational structure and electrochemical properties of ternary oxide electrodes is relatively few.The capacitive performance of RuO₂ or IrO₂ electrodes can be effectively increased by adding moderate non-precious metal MnO₂ and SnO₂ content.The influence of MnO₂/SnO₂ proportion and the temperature on the capacitance of RuO₂ or IrO₂ oxide coating were analyzed and discussed on this paper.The phase structure and microstructure of the electrode material were characterized by XRDand SEM.The electrochemical properties were studied by cyclic voltammetry,constant current charge and discharge and electrochemical impedance spectroscopy in detail.The results were as follows:（1）It can effectively improve electrode capacitance performance when SnO₂ in Ti/Ru0.4S0.6O₂ was replaced by MnO₂ partially.MnO₂ inhibit the crystallization of RuO₂.SnO₂ has good effect of solid solution,can also accept Ru and Mn atoms into the crystal lattice.The storage capacity of Ti/Ru_0.4Sn_0.6-xMn_xO₂（x=0.3～0.5）ternary oxide electrode is higher than Ti/Ru_0.4Sn_0.6O₂ and Ti/Ru0.4Mn0.6O₂ binary oxide electrode under same condition significantly,and has the maximum capacity of 769F/g（x=0.4）.The energy density of Ti/Ru_0.4Sn_0.6-xMn_xO₂（x=0.3-0.5）ternary oxide electrode is higher than Ti/Ruo0.4Sn0.6O₂ and Ti/Ru0.4Mn0.6O₂ electrode under same power density.They have good power and high energy storage density.（2）Preparation temperature has a significant influence on the structure and cpacitor electrode performance of Ti/Ru_0.4Sn_0.2Mn_0.4O₂.Whith the preparation temperature rise,Ti/Ru_0.4Sn_0.2Mn_0.4O₂ coating transition from amorphous to crystalline state.The degree of crystallization increases gradually.Specific capacitance increases with temperature increase firstand then decrease.When the preparation temperature is 290℃,the capacitance of Ti/Ru_0.4Sn_0.2Mn_0.4O₂ ternary oxide electrode is highest.Rct remains low when the temperature over 380℃.（3）The addition of SnO₂ can improve the current response in 0-0.5 V of iridium electrode materials obviously,and can promote the activity of manganese oxide.But it also can inhibit the activity of iridium oxide.The addition of SnO₂ in electrode materials can change the charge transfer resistance,relaxation time constant,and the capacitance response under the different frequency are changing.The capacitance of Ti/Ir_0.2Mn_0.6Sn_0.2O₂ electrode is highest.（4）Ti/Ir_0.2Mn_0.6Sn_0.2O₂ electrode obtain higher capacitance prepared at 340℃.The study is tested under the redox peak（0.75V）of circle curve,the linear slope of AC impedance in the high frequency is higher,capacitive reactance is bigger and the electrode charge storage capacity is larger.