▎ 摘　　要

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 degrees 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. (C)2015 Elsevier Ltd. All rights reserved.