Capacitive Manganese Oxide Thin Films Deposited by Reactive Direct Current Sputtering

Manganese oxide thin films are deposited on graphite foils by a simpler one-step reactive dc sputtering dry process with different volume flow rates of oxygen, sputtering time, pressure, and power. Maximum mass specific capacitance of 344 F/g is obtained in 0.5 M LiCl as well as with optimum sputtering conditions (volume flow rate of oxygen=10 sccm, sputtering pressure=20 mTorr, sputtering power=60 W, and sputtering time=60 min), and this demonstrates its good mass specific capacitance at a higher sweep rate of 100 mV/s. Furthermore, the geometric specific capacitance increases with increasing sputtering pressure, power, and time. Moreover, the electrochemical stability of the electrode decreases with increasing sputtering pressure. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3414823] All rights reserved.