Large-Scale Production of MoO₃-Reduced Graphene Oxide Powders with Superior Lithium Storage Properties by Spray-Drying Process

A MoO₃-reduced graphene oxide (rGO) composite powder with spherical shape is prepared by a simple spray-drying process by applying a water-soluble metal salt. Ammonium molybdate-GO composite powders prepared by spray drying turn into a MoO₃-rGO powder by heat treatment at 300 °C under air atmosphere. The MoO₃ nanocrystals are uniformly dispersed in a crumpled spherical rGO structure. MoO₃ and MoO₃-C powders, both with spherical particles, are also prepared by the same process for comparison of their electrochemical properties. The discharge capacities of the MoO₃, MoO₃-C, and MoO₃-rGO powders after 100 cycles at a current density of 500 mA g^-1 are 506, 738, and 1115 mA h g^-1, respectively, and their corresponding capacity retentions measured from the second cycle are 53, 71, and 92%, respectively. The rGO layers improve the structural stability and electric conductivity of the MoO₃-rGO composite powder. Therefore, the MoO₃-rGO powder shows superior electrochemical properties as compared with the MoO₃ and MoO₃-C powders prepared by the same preparation procedure.