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

Abstract

A series of LiMn_1−xFe_xPO₄ (0 ≤ x ≤ 1) cathode materials with different Mn/Fe ratios have been successfully synthesized by a facile solvothermal method. LiMn_1−xFe_xPO₄/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 LiMn_1−xFe_xPO₄/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, LiMn_0.7Fe_0.3PO₄/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.