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.