Capacity improvement by deficit of transition metals in inverse spinel LiNi1/3Co1/3Mn1/3VO4 cathodes

Although inverse spinel materials have attracted attention because of their unusually high voltage characteristics, their rechargeable capacities are generally less than 50 mAh g −1 , as a result of the coexistence of Li and transition metal ions at 16 d octahedral sites. This work attempted to improve cathode functioning by optimizing the quantities of Li and transition metal ions residing at the 16 d sites of LiNi 1/3 Co 1/3 Mn 1/3 VO 4 . The rechargeable capacity of the LiNi 0.28 Co 0.28 Mn 0.26 V 0.80 O 4 synthesized in the present study was found to be above 120 mAh g −1 , representing the largest capacity reported to date for an inverse spinel material. The results of in-situ XANES analysis demonstrated that the charge–discharge reactions of LiNi 1/3 Co 1/3 Mn 1/3 VO 4 corresponds to the Mn 2+ /Mn 4+ and Co 2+ /Co 3+ redox couples, mainly.