Effects of Particle Size Distribution on Compacted Density of Lithium Iron Phosphate 18650 Battery

The effects of particle size distribution on compacted density of as-prepared spherical lithium iron phosphate (LFP) LFP-1 and LFP-2 materials electrode for high performance 18650 Li-ion batteries are investigated systemically, while the selection of two commercial materials LFP-3 and LFP4 as a comparison. The morphology study and physical characterization results show that the LFP materials are composed of numerous particles with an average size of 300-500 nm, and have well-developed interconnected pore structure and a specific surface area of 13-15 m(2)/g. For CR2032 coin-type cell, the specific discharge capacities of the LFP-1 and LFP-2 are about 165 mAhlg at 0.2 C. For 18650 batteries, results indicate that the LFP-3 material has the highest compacted density of 2.52 g/cm(3 )at a concentrated particle size distribution such as D10 = 0.56 mu m, D50 = 1.46 mu m, and 1)90 = 6.53 mu m. By mixing two different particle sizes of LFP-1 and LFP-2, the compaction density can be increased significantly from 1.90 g/cm(3) to 225 g/cm(3).