LiFePO4/C composites derived from precipitated FePO4 precursor: effects of mixing processes

Grinding, general incipient wetness and competitive incipient wetness were investigated on the preparation of LiFePO4/C (LFP) composites from precipitated FePO4 precursor. This article focuses on the fundamental details of mixing processes for LFP production, of which the literature is sparse. The structure features of LiFePO4/C composites were analyzed by X-ray diffraction (XRD), while the morphologies were characterized by field emission scanning electron microscopy (FESEM). The electrochemical performances were studied by galvanostatic charge/discharge measurements. Both mixing processes and lithium sources are capable of affecting the electrochemical performances by altering the crystallinity, the quality of carbon coating, or even the impurity formation of LiFePO4/C composites. Liquid alkalis caused the formation of impurities and mild decrease of crystallinity, whereas competitive cations did not produce impurities but significantly decreased the crystallinity of LiFePO4/C composites.