Novel Synthesis of 3D Mesoporous FePO from Electroflocculation of Iron Filings as a Precursor of High-Performance LiFePO/C Cathode for Lithium-Ion Batteries.

This study presents an economic and environmentally friendly method for the synthesis of microspherical FePO·2HO precursors with secondary nanostructures by the electroflocculation of low-cost iron fillers in a hot solution. The morphology and crystalline shape of the precursors were adjusted by gradient co-precipitation of pH conditions. The effect of precursor structure and morphology on the electrochemical performance of the synthesized LiFePO/C was investigated. Electrochemical analysis showed that the assembly of FePO·2HO submicron spherical particles from primary nanoparticles and nanorods resulted in LiFePO/C exhibiting excellent multiplicity and cycling performance with first discharge capacities at 0.2C, 1C, 5C, and 10C of 162.8, 134.7, 85.5, and 47.7 mAh·g, respectively, and the capacity of LiFePO/C was maintained at 85.5% after 300 cycles at 1C. The significant improvement in the electrochemical performance of LiFePO/C was attributed to the enhanced Li diffusion rate and the crystallinity of LiFePO/C. Thus, this work shows a new three-dimensional mesoporous FePO synthesized from the iron flake electroflocculation as a precursor for high-performance LiFePO/C cathodes for lithium-ion batteries.