Synergistic Bulk and Interface Modulation of LiMn 0.6 Fe 0.4 PO 4 Cathodes through Mg 2+ Gradient Insertion for Enhanced Li + Diffusion

Olivine-type LiMnxFe1–xPO4 (LMFP) is a promising high-voltage cathode for next-generation lithium-ion batteries; however, its commercialization is hindered by structural instability from Mn3+ Jahn–Teller distortion and sluggish ionic kinetics. Herein, we develop a novel gradient-insertion strategy to address these limitations simultaneously. Through a facile solid-state process, Mg2+ is incorporated into LMFP microspheres, creating a concentration profile. Structural characterization confirms th