Blended spherical lithium iron phosphate cathodes for high energy density lithium–ion batteries

Abstract

Blended spherical cathodes of lithium iron phosphate with different particle sizes were prepared using a physical mixing method. The processability and electrochemical properties of blended spherical cathodes were systematically investigated. The characterization results suggest that the blended spherical cathodes contain two different-sized particles, and smaller particles can fill in the gaps created by larger ones. This structural feature causes an increase in both the connect area of the particles and the compaction density of the blended spherical cathodes, which can enhance the processability of the materials. Increasing the difference in particle sizes between the two groups of blended spherical cathodes is beneficial to obtain an enhanced overall performance, as tested with 14,500 cylindrical batteries, such as higher compaction density, lower resistance, superior high-rate capacity, excellent cycle stability, and higher volume energy density. Therefore, lithium iron phosphate batteries fabricated using the blended spherical cathode with two particle groups that differ significantly in size have a good application prospect.