Electrodeposition of MnO2-Based Nanomaterials as Carbon-Free and Binder-Free Cathodes for Li-O2 Battery

Abstract

Carbon based nanomaterials have been widely used as cathode materials for Li-O2 batteries because of their high conductivity, large surface area, and good ORR catalytic activity. However, instability of carbon under Li-O2 operation poses problems. During recharge, carbon can decompose to form lithium carbonate at high charging potential1, but also react chemically with the discharge product Li2O2 2. Metal oxides, like MnO2 and RuO2, have been investigated as cathode catalysts in Li-O2 batteries3. In this study, MnO2 nanostructure is electrodeposited on stainless steel mesh and applied as a carbon-free and binder-free cathode for non-aqueous Li-O2 battery. To maintain good adhesion and electrical contact between deposited layer and the substrate, the mesh is pre-treated. Benefiting from enhanced electronic contact and large surface area of MnO2, the electrochemical performance is improved. Material characterization and electrochemical impedance spectroscopy (EIS) technique are also utilized to systematically study the electrochemical processes of these carbon-free MnO2-based electrodes. References: [1] M.M.O.Thotiyl, S. A. Freunberger, Z. Peng, and P. G. Bruce, J. Am. Chem. Soc., 135, 494 (2013) [2] B. D. McCloskey, A. Speidel, R. Scheffler, D. C. Miller, V. Viswanathan, J. S. Hummelshøj, J. K. Nørskov, and A. C. Luntz, J. Phys. Chem. Lett., 3, 997 (2012) [3] Z. Ma, X. Yuan, L. Li, Z.F. Ma, D.P. Wilkinson, L. Zhang, and J. Zhang, Energy Environ. Sci., 8, 2144 (2015)