There is a contradiction between the high-rate capability and long calendar life in fast-charging lithium iron phosphate(LiFePO4)Li-ion cells.The synergistic interplay between the anode and electrolyte is investigated to identify the key factors governing capacity fading during high-temperature storage.A single-variable experimental scheme is designed,in which the effects of anode coating,particle size,particle structure,as well as electrolyte composition,on high-temperature stability are examined.The removal of amorphous carbon coating from the graphite anode enhances high-temperature stability at the cost of fast-charging capability,whereas the combination of enlarged particle size and primary particle blending synergistically improves the thermal performance while mitigating the loss of rate capability.Increasing ethyl acetate(EA)content in the electrolyte promotes fast-charging performance but accelerates high-temperature degradation,whereas the introduction of vinylene carbonate(VC)facilitates the formation of a dense solid electrolyte interphase(SEI)film,which suppresses active lithium loss.A synergistic optimization strategy is proposed,involving an anode of 8.5 μm particles+30％mass fraction primary particles,paired with an electrolyte of 50.0％(mass fraction)EA+3.5％(mass fraction)VC.The optimized cells,achieve a high-temperature storage capacity retention of 94.20％,representing an improvement of approximately 2 percentage points over the original system.