Lithium iron phosphate (LiFePO4) is widely used as a low-cost, safer cathode material for Li-ion batteries; however, low ionic and electronic conductivity limit its rate performance.
Now, researchers at UCLA have synthesized LiFePO4/graphite composites in which LiFePO4 nanoparticles are grown within a graphite matrix. The graphite matrix is porous, highly conductive, and mechanically robust, giving the resulting electrodes outstanding cycle performance and high rate capability.
In a paper in the ACS journal Nano Letters, the team reports achieving high-mass-loading electrodes with high reversible capacity (160 mAh g–1 under 0.2 C), ultrahigh rate capability (107 mAh g–1 under 60 C), and outstanding cycle performance (>95% reversible capacity retention over 2000 cycles).
The composite material can lead to electrodes with volumetric energy density as high as 427 Wh L–1 under 60 C—of great interest for electric vehicles and other applications.
The approach provides a new strategy toward low-cost, long-life, and high-power batteries, the researchers concluded.
Fan Li, Ran Tao, Xinyi Tan, Jinhui Xu, Dejia Kong, Li Shen, Runwei Mo, Jinlai Li, and Yunfeng Lu (2021) “Graphite-Embedded Lithium Iron Phosphate for High-Power–Energy Cathodes” Nano Letters doi: 10.1021/acs.nanolett.1c00037