Direct regeneration of high-value LiFePO4 cathode materials with nitrogen doped carbon coating

Lithium iron phosphate (LiFePO 4 ) batteries are currently becoming the primary power system for electric vehicles. However, after the life period, the heavy amounts of electric cars would give rise to a great number of scrapped LiFePO 4 batteries, which inevitably causes serious environmental pollution and resources waste problems. Therefore, it is much imperative and urgent to develop the green technology for regenerating and recycling these scrapped LiFePO 4 batteries. Herein, we reported an efficient and straightforward solid-phase strategy to achieve the direct regeneration of scrapped LiFePO 4 cathode materials. The decommissioned LiFePO 4 was successfully regenerated by adding lithium carbonate and melamine under the heat treatment condition, and the battery performance was repaired. The electrochemical performance of regenerated LiFePO 4 is even higher than that of the unused LiFePO 4 at 0.05 C. Moreover, the regenerated LiFePO 4 also exhibits excellent capacity preservation rate of 99.03 % after 200 cycles and outstanding rate capability at 5 C with a discharge capacity of 116 mAh/g. The systematical study demonstrates that the nitrogen-doped carbon coatings play vital role in improving the properties of regenerated LiFePO 4 cathode materials. This work provides a potential approach to resolve the scrapped LiFePO 4 cathode materials to meet the coming retired tide of lithium ion batteries.