Synthesis of carbon-coated LiMn0.8Fe0.2PO4 materials via an aqueous rheological phase-assisted solid-state method

Synthesis method is crucial to the improved electrochemical performances of LiMnPO 4 materials with poor electronic and ionic conductivity for large-scale preparation. Here, carbon-coated LiMn 0.8 Fe 0.2 PO 4 materials were synthesized through a rheological phase-assisted solid-state method combined with freeze-drying. Effect of different carbon sources on the structure, morphology, and electrochemical performance of as-prepared LiMn 0.8 Fe 0.2 PO 4 materials was investigated. The results suggest that LiMn 0.8 Fe 0.2 PO 4 materials with citric acid as carbon sources show a high discharge capacity with 164, 122, and 106 mA h g −1 at 0.1, 1, and 5 C, and a capacity retention of around 99.6% after 100 cycles at 1 C. This can be attributed to higher surface area, intense peak of sp 2 N–C=N bonds, and uniform particle distribution resulting from the rheological phase formed using citric acid as carbon sources combined with freeze-drying. The rheological phase-assisted solid-state method is a promising route for production of LiMn 0.8 Fe 0.2 PO 4 materials with excellent performances.