Boosting charge diffusion kinetics of LiMn0.5Fe0.5PO4/MXenes composite cathodes by a synergistic interfacial modification

Concerns regarding the raw cost and energy density of lithium-ion batteries have sparked significant interest in LiMn₁₋ ₓ Fe ₓ PO₄ (LMFP) cathodes. However, their poor electronic conductivity with low Li + diffusion coefficient hinders the practical application. In this study, a LMFP/C@MXene heterostructured cathode with dual coating modification with amorphous sucrose and conductive Ti₃C₂T x is prepared via solid-state method with stepwise heating. Electrochemical tests demonstrate that the optimal LMFP/C@MXene cathode retains a reversible capacity of 120 mA h g −1 after 100 cycles at 1C rate. Also, and it maintains a capacity retention rate at 5C rate as high as 91.26% after 600 cycles, which is significantly superior to the unmodified LMFP material (87.7%). Thus, the composite LMFP/C@MXene material achieves the synergistic improvement of rate performance and cycling stability by constructing conductive paths for charge transport with rapid diffusion kinetics. It also buffers volume deformation of cathode electrolyte interphase (CEI) by adding crown ether in the electrolyte, thus inhibitig surficial Mn dissolution for the robust protection of the crystalline LMFP grains.