International Journal of Hydrogen Energy, Vol.40, No.34, 10876-10882, 2015
Monodisperse MPd (M: Co, Ni, Cu) alloy nanoparticles supported on reduced graphene oxide as cathode catalysts for the lithium-air battery
Addressed herein is the electrocatalyst performance of the monodisperse MPd (M: Co, Ni, Cu) alloy nanoparticles (NPs) supported on reduced graphene oxide (rGO) for the non-aqueous Li-air battery. MPd alloy NPs were prepared by using a well-established surfactant-assisted organic solution phase protocol comprising the co-reduction of palladium(II) acetylacetonate and M(acetate)(2) or M(acetylacetonate)(2) by borane-based mild reducing agents in oleylamine. As-synthesized Co3Pd7, Ni3Pd7 and CuPd NPs have uniform particle size distribution with the average particle size of 3.5, 3.4 and 3.0 nm, respectively. The colloidal MPd NPs were then supported on rGO before their use as cathode catalysts in the non-aqueous Li-air battery. The charge discharge curves of Li-air electrodes using rGO-CuPd, rGO-Co3Pd7 and rGO-Ni3Pd7 catalysts were investigated at a current rate of 100 mA g(-1). The specific discharge capacities were found as 4407 mA h g(-1) for rGO-CuPd, 3158 mA h g(-1) for rGO-Co3Pd7 and 2512 mA h g(-1) for rGO-Ni3Pd7. Ex-situ FTIR analyses after the 10 cycle recyclability test revealed that Li2O2 is the main component of the discharge products. The lifetime of the cathode electrodes during the first 10 cycles was found to be 100 h for rGO-Co3Pd7, 130 h for rGO-CuPd and 180 h for rGO-Ni3Pd7. The Ni3Pd7 has the highest total capacity of 8175 mA h g(-1), over the first 10 cycles. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
Keywords:Palladium;Alloy nanoparticles;Reduced graphene oxide;Electrocatalyst;Lithium-air battery;Lithium-oxygen battery