Micro-Reducing Atmosphere with High-Rate Capability Performance of Carbon-Coated LiFePO4 Prepared from Spray-Drying-Assisted Solid-Phase Reaction

Nanostructured mesoporous LiFePO4/C (LFP/C) composite was prepared by spray-drying-assisted solid-state reaction with FeSO4 and LiOH as reactants. Instead of tubular furnace in various atmospheres (nitrogen or argon) of the calcination method, box furnace embedded with biomass waste rice husk char as embedded agent did not need to supplement atmosphere method was first applied in this study. The influence of micro-reducing atmosphere on the phase formation and particulate morphology of product was systematically investigated by XRD, SEM, TEM, XPS and Raman techniques. Rice husk char embedded was beneficial to the formation of LFP/C materials with good electrochemical performance and high stability. XRD and Raman test results show that pure LFP material can be prepared in the micro-reducing atmosphere, and the addition of glucose is conducive to the formation of crystallized carbon network. XPS of LFP/C materials demonstrate the micro-reducing atmosphere is conducive to the reduction of Fe3+ to Fe2+. Cathodes of LFP/C provided specific discharge capacities of 158 mA h/g and 128 mA h/g at 0.2 C and 10 C, respectively. The low cost spray-drying-assisted solid-phase reaction may be a practical way for the economic synthesis of LFP/C as high-rate electrodes of lithium-ion batteries.