Process for the preparation of LiFePO₄-carbon composites

摘要

The present invention relates to a process for the preparation of particles comprising at least one compound according to general formula (I) M1aM2bM3cOoNnFf (I) wherein M1, M2, M3 O, N, F, a, b, c, o, n and f have the following meanings: M1 at least one alkaline metal, M2 at least one transition metal in oxidation state +2, M3 at least one non-metal chosen form S, Se, P, As, Si, Ge and/or B, O oxygen, N nitrogen, F fluorine, a 0.8-4.2, b 0.8-1.9, c 0.8-2.2, o 1.0-8.4, n 0-2.0 and f 0-2.0, wherein a, b, c, o, n and f are chosen to ensure electroneutrality of the compound according to general formula (I), and carbon, comprising at least the following steps: (A) providing an essentially aqueous mixture comprising at least one compound comprising M1, at least one compound comprising M2 having at least partially an oxidation state higher than +2, optionally at least one compound comprising M3, at least one compound comprising N, if present, and/or at least one compound comprising F, if present, at least one polysaccharide comprising glucose having a molecular weight M of at least 50000 g/mol as carbon precursor and at least one reducing agent, (B) drying the mixture provided in step (A), in order to obtain a solid particle and (C) calcining the solid particle obtained from step (B) at a temperature of 300 to 950° C.

主权项

1. A process for producing a particle, the process comprising:
(B) drying an essentially aqueous mixture to obtain a solid particle, the mixture comprising:
a first compound comprising M1;a second compound comprising M2 and having an oxidation state at least partially higher than +2;optionally, a third compound comprising M3;optionally, at least one selected from the group consisting of a fourth compound comprising N and a fifth compound comprising F;a polysaccharide comprising glucose and having a molecular weight of at least 50000 g/mol;at least one of a monosaccharide and a disaccharide; andat least one reducing agent selected from the group consisting of hydrazine, a hydrazine derivative, a hydroxyl amine, a hydroxyl amine derivative, a reducing sugar, an alcohol, ascorbic acid, a compound comprising an oxidizable double bond, and a compound comprising a phosphorous atom having an oxidation state of +3; and (C) calcining the solid particle at a temperature of 300 to 950° C.;
wherein:the solid particle comprises carbon and a compound of formula (I):
M1aM2bM3cOoNnFf  (I), wherein:
M1 is at least one alkaline metal;M2 is at least one transition metal having an oxidation state of +2;M3 is at least one non-metal selected from the group consisting of S, Se, P, As, Si, Ge, and B;O is oxygen, N is nitrogen, F is fluorine; anda is 0.8-4.2, b is 0.8-1.9, c is 0.8-2.2, o is 1.0-8.4, n is 0-2.0, and f is 0-2.0;the compound of formula (I) is electroneutral;the polysaccharide is present in an amount of 40-85% by weight based on a total weight of the polysaccharide and the at least one of the monosaccharide and the disaccharide; andthe at least one of the monosaccharide and the disaccharide is present in an amount of 15-60% by weight based on the total weight of the polysaccharide and the at least one of the monosaccharide and the disaccharide.