Novel Synthesis of 3D Mesoporous FePO<sub>4</sub> from Electroflocculation of Iron Filings as a Precursor of High-Performance LiFePO<sub>4</sub>/C Cathode for Lithium-Ion Batteries
Jiawu Peng, Xiaoting Hong, Qiongxiang Zhou, Kwan San Hui, Bin Chen
Abstract
High Resolution Image Download MS PowerPoint Slide This study presents an economic and environmentally friendly method for the synthesis of microspherical FePO 4 ·2H 2 O 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 4 /C was investigated. Electrochemical analysis showed that the assembly of FePO 4 ·2H 2 O submicron spherical particles from primary nanoparticles and nanorods resulted in LiFePO 4 /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 –1, respectively, and the capacity of LiFePO 4 /C was maintained at 85.5% after 300 cycles at 1C. The significant improvement in the electrochemical performance of LiFePO 4 /C was attributed to the enhanced Li + diffusion rate and the crystallinity of LiFePO 4 /C. Thus, this work shows a new three-dimensional mesoporous FePO 4 synthesized from the iron flake electroflocculation as a precursor for high-performance LiFePO 4 /C cathodes for lithium-ion batteries.