Study On The Capacitance Performance Of Ir-Ta Based Oxide Anodes

Electrode materials play an important factor in determining the properties of the electrochemicalcapacitor.IrO₂has a good pseudocapacitive performance and corrosion resistance,so it has been widelyused in capacitive storage materials.In order toimprove the structure and capacitance performance of IrO₂ coating.It need to adds some proper components.Ta₂O₅is relatively stable forthe electrochemical properties and exists in the form of amorphous structure at low temperature.IrO₂-Ta₂O₅ electrode has been taken as a good anode coating withgood oxygen evolution.But there is little research on the capacitance performance of IrO₂-Ta₂O₅ coating.The capacitive performance of RuO₂ electrodes can be effectively increased byadding proper amount of Ta₂O₅.Ti/IrO₂-Ta₂O₅,Ti/IrO₂-MnO_x-Ta₂O₅ and Ti/IrO₂-SnO₂-Ta₂O₅ coatings were prepared by thermal decomposition method.Thephase structure and morphology of the electrodes were analyzed by XRD and SEM.The electrochemical properties were systematically studied by cyclic voltammetry,AC impedance and constant current charge discharge.The results were as follows:?1?Ti/IrO₂-Ta₂O₅ electrodes were prepared by thermal decomposition method with different Ta contents/temperature.With increasing Ta contents,the crystallization degree decreased,the results showed that Ta₂O₅ can inhibit crystallization of the IrO₂.The critical crystallization temperature range of the Ti/IrO₂-Ta₂O₅ electrode is between 350? to 370?,which is beneficial to the improvement of the capacitance performance of the electrode.The specific capacitance increases first with increasing temperature and then decrease.When it's prepared at 370?,the specific capacitance reaches the maximum?239.2F/g?on the 60mol%Ta electrode.?2?The different compositions of Ti/IrO₂-MnO_x-Ta₂O₅ electrodes were prepared at 360?.Ta₂O₅ inhibits forming the iridium manganese solid solution and the crystallization.Withadding 40mol%Ta,the IrO₂ diffraction peak disappears in the coating,and the specific capacitance increaseswith increasing Ta content first and then decreases.The specific capacitance of the Ti/IrO₂-MnO_x-Ta₂O₅ electrode coating canreach 356.41F/g by adding 30mol%Ta.?3?The preparing temperature has a significant influence on the structure and the capacitance of theTi/IrO₂-MnO_x-Ta₂O₅electrode.The electrodeprepared at 330? to 390?mainly exists in the form of microcrystall ine.The specific capacitance increases with increasing temperature first and then decreases.The maximum of the specific capacitance is 350F/g at 370?.?4?The effect of the capacitance of Ti/IrO₂-SnO₂-Ta₂O₅ electrode prepared at different temperature.Amorphous and crystalline coexist the triatemeperature range was studied.The specific capacitance increasedwith increasing temperature first and then decreased.When it's prepared at 370?,the capacitance reaches the maximum?382.9F/g?.It has a good cycling stability.The integral charge increased 4.6%after 7000 cycles than that of the first cycle.