Utilizing egg lecithin coating to improve the electrochemical performance of regenerated lithium iron phosphate

A series of egg lecithin coating LiFePO4 composites have been prepared by a simple mechanochemistry activation and sintering processes using the regenerated LiFePO4 as raw materials. The mechanical forces of high energy ball milling have induced activation or chemical changes of different components. The as-prepared LiFePO4 composites showed stable (C+N+P) co-coating layers with N-C and P-C bonds wrapped LiFePO4 particles and smaller uniform particle sizes, which can shorten the diffusion distance of lithium ions and electrons, and offer a good electronic conduction between the LiFePO4 particles. The LiFePO4/C composite coating with 15% egg lecithin exhibited the average specific capacities of 164.9 mAh g−1 at the low C-rate of 0.2 C; at C-rate of 5 C, the electrode can deliver the specific capacity of 120 mAh g−1 with a capacity retention of 93% after 100 cycles; even at high rate of 20 C, this electrode materials can still keep 100.7 mAh g−1, which is 41% greater than its pristine counterpart. More interestingly, the raw material in this work is the recycled LiFePO4 produced from the spent power batteries, which also demonstrates a greatly potential approach to utilize the regenerated LiFePO4 from the spent batteries into high-performance cathode materials for Li-ion batteries applications.