Crumpled Graphene–Molybdenum Oxide Composite Powders: Preparation and Application in Lithium‐Ion Batteries

Crumpled graphene–MoO 2 composite powders are directly prepared by means of spray pyrolysis and from a stable graphene oxide colloidal solution in the presence of Mo ions. The crumpled graphene–MoO 2 composite powders are transformed into MoO 3 ‐based composite powders after post‐treatment at 300 °C. The transmission electron microscopy and dot‐mapping images of the post‐treatment composite powders show uniform distribution of MoO 3 nanocrystals in the crumpled graphene powders. The two typical D and G bands of graphene are observed at 1350 and 1590 cm −1 , respectively, in the Raman spectrum of the graphene–MoO 3 composite. In addition, the crumpled graphene–MoO 3 powders exhibit superior electrochemical behavior compared to that of pure MoO 3 as an anode material for lithium‐ion batteries. The initial discharge capacities of the graphene–MoO 3 composite and bare MoO 3 powders at a current density of 2 A g −1 are 1490 and 1225 mA h g −1 , respectively. The capacity retention of the graphene–MoO 3 composite is 87 % after the first cycle, whereas that of bare MoO 3 is 47 %, as measured after 100 cycles. The reversible discharge capacity of the graphene–MoO 3 composite decreases slightly from 1228 to 845 mA h g −1 as the current density increases from 0.5 to 3 A g −1 .