Development of pseudocapacitive molybdenum oxide-nitride for electrochemical capacitors

A thin film Mo oxide-nitride pseudocapacitive electrode was synthesized by electrodeposition of Mo oxide on Ti and a subsequent low-temperature (400 °C) thermal nitridation. Two nitridation environments, N2 and NH3, were used and the results were compared. Surface analyses of these nitrided films showed partial conversion of Mo oxide to nitrides, with a lower conversion percentage being the film produced in N2. However, the electrochemical analyses showed that the surface of the N2-treated film had better pseudocapacitive behaviors and outperformed that nitrided in NH3. Cycle life of the resultant N2-treated Mo oxide-nitride was also much improved over Mo oxide. A two-electrode cell using Mo oxide-nitride electrodes was demonstrated and showed high rate performance.