Accelerating charge-transfer kinetics in LiFePO4 cathode through a construction of multifunctional layer for advanced lithium-ion batteries

LiFePO4 has emerged as the most favorable cathode material for lithium-ion batteries due to its high safety and long cycling life. However, the inherent sluggish charge transfer kinetics have greatly restricted its usefulness in low-temperature and high-rate operations. Herein, a uniform multifunctional layer enriched with N and F co-doped carbon was meticulously engineered on the LiFePO4 surface through an efficient solid-state calcination method. Theoretical and experimental analyses conclusively show that this layer effectively modifies electronic states and reduces Li-Fe antisite defects in LiFePO4. This enhancement significantly improves lithium affinity and Li+ transport efficiency, leading to superior electrochemical performance, especially at high rates and under low-temperature conditions. The treated LiFePO4 (LFP@NCF) demonstrated outstanding capacities of 169.51 mAh/g at 0.1C, maintaining capacity retention of 103.18 % after 300 cycles at −20 °C and 1C, and achieved a rate capacity of 125.49 mAh/g at 20C. This research explores the role of N and F dopants in carbon layers in improving charge transfer kinetics for LiFePO4 cathodes, providing insights for developing cathode materials for lithium-ion batteries in challenging environments.