Insights into the enhanced electrochemical performance of MnV2O6 nanoflakes as an anode material for advanced lithium storage

Binary transition metal oxides (BTMOs) are regarded as potential anode materials for lithium-ion batteries (LIBs) owing to their low cost, high specific capacities, and environmental friendliness. In this work, MnV2O6 nanoflakes are successfully synthesized by a facile hydrothermal method. When evaluated as an anode material for LIBs, benefiting from the activation process, the as-prepared MnV2O6 nanoflake electrode delivers a high reversible specific capacity of 1439 mA h g-1 after 300 cycles at a current density of 200 mA g-1, and especially presents a specific capacity of 1010 mA h g-1 after 700 cycles at a higher current density of 1 A g-1. Furthermore, MnV2O6 shows a pleasurable rate capability; a reversible specific capacity of 867 mA h g-1 can be obtained at a current density of 2000 mA g-1, and when the current density is returned to 200 mA g-1 and continues for another 80 cycles, the specific capacity can still reach 1499 mA h g-1. Meanwhile, the morphology variation and electrochemical kinetic behavior of the MnV2O6 electrode during cycling are scrutinized in detail. After that, the electrochemical reaction mechanism of MnV2O6 during the discharge/charge process is corroborated by in situ X-ray diffraction (XRD), which involves the coexistence of a conversion reaction and solid solution behavior. The practical application of MnV2O6 nanoflakes as an anode material is examined as well. Sure enough, the NCM811//MnV2O6 full-cell exhibits excellent lithium-storage performance.