| Many transition metal compounds are found to possess promising pseudocapacitive properties. Research on these transition metal compounds, especially Mo, V and W based materials, is still limited. This project aimed to investigate cost-effective methods utilizing inexpensive transition metal compounds to produce EC electrodes with high energy density and power capability. Mo(O,N)x was developed as a pseudocapacitive electrode material by electrodeposition of Mo oxide followed by low-temperature thermal nitridation in a N2 environment. The partial nitridation significantly improved the electrochemical properties, including capacitive behavior, power capability and cycle life. The device performance can be improved with an asymmetric configuration using an electrodeposited WO3 electrode. An electrolessly deposited V mixed oxides electrode also showed ideal capacitive behaviors and good cycle life. By tuning the fabrication methods, the electrodes (i.e. Mo(O,N)x, WO3 and VOx.yH2O) were developed with low cost processes. |
