N–doped carbon coating boosts the construction of high–performance regenerated LFP cathodes

During long–term cycling of LiFePO 4 (LFP) cathodes, the accumulation of surface side reactions usually causes lithium loss and gradual formation of iron phosphate (FP) phase, thus resulting in progressive performance degradation of LFP. Herein, a N doping–assisted regeneration strategy for LFP cathodes is proposed. The inherent carbonaceous impurities in spent LFP are utilized to reconstruct a carbon coating, along with simultaneous N doping by the added urea, thereby enabling the regeneration of high–performance LFP cathodes. The regenerated material (N–doped carbon coated regenerated LFP, abbreviated as RLFP@NC) has a well–maintained crystal structure, which shows an excellent discharge capacity of 106.3 mAh g −1 at a high rate of 5C (1C = 170 mA g −1 ) and a remarkable cycling stability with a capacity retention of 87.2 % after 500 cycles. Theoretical calculations reveal that this enhanced structural stability and improved electrical conductivity are primarily attributed to the presence of N–doped carbon coating. Furthermore, the economic analysis demonstrates that our adopted method is featured with excellent cost–effectiveness and environmental friendliness, offering a viable approach for the green and low–carbon recycling of LFP cathodes.