FEC添加剂提升预锂化石墨负极的循环稳定性OA

The energy density and cycling stability of commercial graphite anode-based lithium-ion batteries(LIBs)still have considerable potential for improvement.Prelithiation of graphite and the incorporation of electrolyte additives to enhance interfacial stability are among the most effective strategies for overcoming the performance limitations of graphite-based LIBs.Herein,fluoroethylene carbonate(FEC)is employed as a film-forming electrolyte additive to improve the electrochemical performance of prelithiated graphite anodes by modulating interfacial kinetics.The prelithiated graphite/Li half-cell utilizing the baseline electrolyte retains 43.0％of its capacity after 300 cycles at a rate of 0.2 C,compared with only 27.9％for the non-prelithiated counterpart.Upon the addition of 1％FEC,the battery demonstrates negligible capacity decay after 600 cycles.Furthermore,when the operating temperature is reduced from 25℃to 0℃,the capacity loss of the battery decreases from 39.5％without FEC to 15.7％with FEC.In graphite||LiFePO4 full cells,the capacity retention of the non-prelithiated graphite increases from 71.6％to 73.7％after 200 cycles at 0.5 C with the addition of FEC,whereas that of the prelithiated graphite electrode rises from 94.2％to 97.1％.These experimental results confirm that the synergistic effect of graphite prelithiation and the FEC additive significantly enhances the cycling stability of the battery.Therefore,FEC induces the formation of a high-quality solid electrolyte interphase on the surface of the prelithiated anode,improving the electrochemical performance of graphite-based LIBs under ambient and low-temperature conditions.This strategy provides a practical approach and theoretical basis for the development of high-energy-density LIBs capable of operating reliably in extreme environments.