High-Performance Cathode Based on Microporous Mo-V-Bi Oxide for Li Battery and Investigation by Operando X-ray Absorption Fine Structure.

The development of cathode-active material of Li battery is important for the current emerging energy transferring and saving problems. A stable crystalline microporous complex metal oxide based on Mo, V, and Bi is an active and suitable material for Li battery. High capacity (380 Ah/kg) and stable cycle performance are achieved. X-ray absorption near-edge structure analyses demonstrate that the original Mo6+ and V4+ ions are reduced to Mo4+ and V3+ in the discharging process, respectively, which results in a 70-electron reduction per formula. The reduced metal ions can be reoxidized reversibly in the next charging process. Furthermore, extended X-ray absorption fine structure analyses reveal that the Mo-O bonds in the material are lengthened in the discharging process probably due to interaction with Li+ without change of the basic structure.