The rate behavior of lithium batteries is one of the key topics for their wide applications. A MoO2/graphene oxide nanohoneycomb synthesized by a preform-decomposition process displays a cycle induced activation behavior at the current densities of 0.1, 0.2, 0.5, and 1.0 A g–1. The reversible capacities can reach to 1128, 759, 723 and 673 mAh g–1 after 100 cycles, respectively. While it shows an almost constant capacity around 196 mAh g–1 at a high current density of 10.0 A g–1. The analyses based on the discharge/charge voltage profiles, their corresponding differential curves, rate cycle performance, as well as the phase analysis after discharging show the contributions of the reversible insertion of Li into the MoO2 to form Li0.98MoO2, the reversible conversion reaction from Li0.98MoO2 to Mo and Li2O, as well as surface adsorption at the current densities of 0.1, 0.2, 0.5, 1.0 A g–1. When cycled at a higher current density, a large over potential happens during insertion/desertion process with a significantly decay of conversion reaction. The conversion reaction almost can not work at 10.0 A g–1.
Published in: "Journal of the Electrochemical Society".