Lithium iron phosphate cathode materials with enhanced energy density and power performance

摘要

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