Titanium‐Stabilized LiMn 0.6 Fe 0.4 PO 4 @C Cathode: Alleviating Stress Release and Interfacial Degradation for High‐Energy Lithium Batteries

LiMn x Fe 1− x PO 4 (LMFP) is a promising cathode material due to its high operating voltage, excellent low‐temperature performance, and cost‐effectiveness. However, several unavoidable defects, such as the rapid decay of the manganese plateau and the continuously increasing direct current resistance (DCR), greatly restrict its further application. Here, we separately investigated the anionic PO 4 3− and cationic Ti 4+ modification for the LMFP cathode. The results show that Ti modification improves the bulk structure and interfacial stability, while also reducing the particle size. This is beneficial for alleviating stress release of the LMFP under high voltage and inhibiting interfacial transition metal dissolution, thus significantly improving the electrochemical performance. The Ti‐modified sample of Ti‐LMFP@C exhibits an initial capacity of 125.88 mAh g −1 in 18650 full cell at 1C rate, with a capacity retention of 96.98% even after 300 cycles, which is much higher than the bare sample and PO 4 3− ‐modified sample. In addition, the Ti‐LMFP@C battery presents a lower DCR under different states of charge (SOC). The cycled battery disassembly analysis confirms that the transition metal dissolution can be effectively suppressed and the anode structure stability can be improved through the Ti modification. These findings provide a practical strategy for designing a high‐performance LMFP‐based cathode.