Graphite-Embedded Lithium Iron Phosphate for High-Power-Energy Cathodes.

Li, Fan; Tao, Ran; Tan, Xinyi; Xu, Jinhui; Kong, Dejia; Shen, Li; Mo, Runwei; Li, Jinlai et al. · Nano Lett · 2021

basic_science · Level V

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Abstract

Lithium iron phosphate (LiFePO<sub>4</sub>) is broadly used as a low-cost cathode material for lithium-ion batteries, but its low ionic and electronic conductivity limit the rate performance. We report herein the synthesis of LiFePO<sub>4</sub>/graphite composites in which LiFePO<sub>4</sub> nanoparticles were grown within a graphite matrix. The graphite matrix is porous, highly conductive, and mechanically robust, giving electrodes outstanding cycle performance and high rate capability. High-mass-loading electrodes with high reversible capacity (160 mA h g<sup>-1</sup> under 0.2 C), ultrahigh rate capability (107 mA h g<sup>-1</sup> under 60 C), and outstanding cycle performance (>95% reversible capacity retention over 2000 cycles) were achieved, providing a new strategy toward low-cost, long-life, and high-power batteries. Adoption of such material leads to electrodes with volumetric energy density as high as 427 W h L<sup>-1</sup> under 60 C, which is of great interest for electric vehicles and other applications.