Abstract:

A spherical lithium iron phosphate material LFP-1 was prepared by high-energy ball milling and spray drying,and the 18650 battery was fabricated to measure the compacted density of the electrode sheet.At the same time,a commercial lithium iron phosphate material LFP-2 was selected as a comparison.The test results showed that both LFP materials consist-ed of particles with an average particle size of 300~500 nm,a specific surface area of 13~15 m²/g and a carbon mass fraction of about 1.5%.The charge and discharge test of the CR2032 button battery showed that the specific discharge capacity of LFP-1 was approximately 165 mA·h/g at 0.2C,which was similar to that of commercial lithium iron phosphate material LFP-2.The results of the prepared 18650 cell showed that the highest compacted density of the electrode sheet prepared from the commercial lithium iron phosphate LFP-2 could reach 2.52 g/cm³,which was significantly higher than that 2.25 g/cm³ of the LFP-1,which may be related to the different particle size distribution of the material.

Key words: lithium iron phosphate, 18650 batteries, compacted density, slurry viscosity