Achieving Fast Mn Redox Kinetics with Solvothermal Synthesized (010) Facet Preferential LiMn0.5Fe0.5PO4 Nanoplates for Li-Ion Batteries

Abstract

A well-designed solvothermal approach has been employed to synthesize olivine LiMn_0.5Fe_0.5PO₄ (LMFP) cathode material with a nanoplate configuration. This method precisely controls crystal growth to achieve a high proportion of (010) facets while minimizing intrinsic defects. These modifications significantly enhance lithium-ion diffusion kinetics and optimize the electrochemical performance of LMFP. The nanoscale of the (010) facets and the reduced anti-site defect concentration in the MP-PRO sample functionalize jointly to promote lithium-ion transport during the long-cycle. Furthermore, the superior electrochemical performance is closely linked with significantly reduced impedance and enhanced Mn redox kinetics. Both theoretical calculations and experimental results indicate that the confinement effect induced by 1,3-propanediol directs facet orientation and confines nanoplate growth. Compared to the product synthesized using water (MP-H₂O), the 1,3-propanediol-based sample (MP-PRO) delivers a high specific capacity of 130.7 mAh g⁻¹ at 5C and demonstrates excellent cycling stability, with an 84.6% capacity retention after 1000 cycles. This study provides new insights into the kinetics of Mn redox in LMFP electrodes and reveals an effective electrode structure design to realize long-life high rate batteries.