Preparation and Optimization of ZrO ₂ ‐Coated LiMn _0.5 Fe _0.5 PO ₄ Cathode Material via Ionic Liquid‐Assisted Solid‐State Method

Driven by the global energy structure transition, new energy vehicles and large‐scale energy storage devices are exhibiting a rapid development trend, which also presents more rigorous performance requirements for lithium‐ion batteries (LIBs) in terms of energy density, cycle life, and safety performance. LiMn _x Fe _1‐x PO ₄ (LMFP) has become a hot research object owing to its wide voltage working range, excellent thermodynamic stability, and other characteristics. However, the poor electronic conductivity, slow Li ⁺ diffusion rate, and insufficient utilization rate of high‐voltage plateaus limit its commercial application. In this article, the nanoscale LiMn _0.5 Fe _0.5 PO ₄ (LMFP55) cathode material was synthesized by a method combining mechanochemical ball milling with high‐temperature solid‐state calcination. Then, the LMFP cathode materials modified with different zirconium dioxide (ZrO ₂ ) coating amounts were prepared by the ionic liquid‐assisted solid‐phase method. The effect of coating content on the structure and electrochemical performance of the materials was investigated. We found that the LMFP coated with 3 wt% ZrO ₂ has optimal performance of retention ratio up to 96.01% after 200 cycles at 0.1C, significantly improving the long‐life cycle performance and interface stability of the material. This article provides an effective approach for optimizing LIBs and advancing their development.