LITHIUM IRON PHOSPHATE CATHODE MATERIALS WITH ENHANCED ENERGY DENSITY AND POWER PERFORMANCE

摘要

The invention is related to a cathode material comprisingparticles having a lithium metal phosphate core and apyrolytic carbon deposit, said particles having a syntheticmultimodal particle size distribution comprising at leastone fraction of micron size particles and one fraction ofsubmicron size particles, said lithium metal phosphatehaving formula LiMPO4 wherein M is at least Fe or Mn.Said material is prepared by method comprising thesteps of providing starting micron sized particles andstarting submicron sized particles of at least one lithiummetal phosphate or of precursors of a lithium metalphosphate ; mixing by mechanical means said startingparticles ; making a pyrolytic carbon deposit on the lithiummetal phosphate starting particles before or after themixing step, and on their metal precursor before or aftermixing the particles ; optionally adding carbon black,graphite powder or fibers to the said lithium metalphosphate particles before the mechanical mixing.