Electrochemical properties of LiFePO4/C composite cathode material: Carbon coating by the precursor method and direct addition

Carbon-coated LiFePO4 (LiFePO4/C) composite cathode-active materials of submicron size and phase-pure olivine structure were synthesized by a mechanical activation (MA) process. The conductive carbon coating was achieved by addition of (i) carbon powder directly or (ii) sucrose as the carbon precursor, during synthesis. LiFePO4/C containing 6 wt% carbon prepared by the two methods showed good electrochemical properties as cathodes in lithium batteries at room temperature with high active material utilization of >94% at 0.1 C rate and stable cycle performance. The sucrose precursor method leads to the formation of a thin, porous and more uniform carbon coating around the particles and results in a slightly higher discharge capacity (∼3%) compared to the other sample.