Patent ID: 8722004

Claim:
A method for the preparation of a lithium phosphate compound with an olivine crystal structure, comprising: (a) providing an aqueous solution containing at least one M metal ion, a lithium ion, a phosphate ion and a nitric acid; (b) adding a soluble reductant and a carbon source to the aqueous solution in Step (a); (c) dehydrating the aqueous solution followed by a self-propagating combustion at 150-300° C.; and (d) heating a combusted product obtained from the self-propagating combustion to promote crystallization of the combusted product, in order to obtain a final product with a complete crystal phase, wherein an amount of the nitric acid added in Step (a) is within 80-120% by weight of the final product; and the soluble reductant in Step (b) is selected from the group consisting of urea (CO(NH 2 ) 2 ), citric acid (C 6 H 8 O 7 ), glycine (C 2 H 5 NO 2 ), alanine (C 3 H 7 NO 2 ), carbohydrazide (CH 6 N 4 O), diformyl hydrazide (C 2 H 4 N 2 O 2 ), oxalyl dihydrazide (C 2 H 6 N 4 O 2 ) and combinations thereof.