LITHIUM BATTERIES CONTAINING LITHIUM-BEARING IRON PHOSPHATE AND CARBON

摘要

Preparing a composite material of lithium iron phosphate and carbon comprises: formation of a precursor mixture containing lithium phosphate, iron(II) phosphate and a material containing carbon in an inert atmosphere; grinding the precursor mixture; and calcining the grinded mixture during which the pyrolysis of material containing carbon and the formation of crystals of lithium iron phosphate takes place. Preparing a composite material of lithium iron phosphate and carbon comprises: formation of a precursor mixture containing lithium phosphate, iron(II) phosphate and a material containing carbon in an inert atmosphere; grinding the precursor mixture; and calcining the grinded mixture during which the pyrolysis of material containing carbon and the formation of crystals of lithium iron phosphate takes place, where the grinding is an high energy industrial nano-grinding with balls for a predetermined period to produce the precursor mixture to mechanical energy activation for obtaining micrometer mixture of nanometric particles. Independent claims are included for: (1) electrode material (A) having lithium-iron-boron-phosphate of formula (Li aFe bB cPO 4/C), where (A) is in the form of micrometric mixture of nanometric particles having a maximum size of less than 50 nm measured by transmission electron microscopy and the micrometric mixture has an average size of 0.5-60 mu m, preferably 2-15 mu m in methanol measured by laser granulometry; (2) electrode made of composite material of lithium iron phosphate and carbon, having a surface capacity of less than 2 mAh/cm 2>, a specific practical electrode capacity of 150-170 m Ah/g, preferably 155-170 m Ah/g or comprising the electrode material; and (3) lithium-ion electrochemical cell comprising the electrode. a : 0.85-1.08; and b, c : 0-0.1, where the gamma + beta is = 1.