High performance nano-sized LiMn1-xFexPO4 cathode materials for advanced lithium-ion batteries

摘要

A series of LiMn1-xFexPO4 (0 <= x <= 1) cathode materials with different Mn/Fe ratios have been successfully synthesized by a facile solvothermal method. LiMn1-xFexPO4/C nanoparticles have a width of ca. 50 nm and a length of 50-200 nm, coating with a thin carbon layer (ca. 2 nm). The effects of iron content on the series of LiMn1-xFexPO4/C materials have been systemically investigated. The homogeneous solid solution and highly conducting nanostructure lead to excellent specific capacities, superior discharge rate capabilities and energy densities for x values in the range of 0.2-0.3. For example, LiMn0.7Fe0.3PO4/C can deliver discharge capacities of 167.6, 153.9 and 139.1 mA h g(-1) at 0.1C, 1C, and 5C rate, respectively, and shows excellent cycle stability at different rates, and can be considered as a cathode candidate for practical application in advanced lithium-ion batteries.