Synthesis method for carbon material based on LixM1-yM'(XO4)n
First Claim
1. A method for the synthesis of a compound of the formula LixM1−
- yM′
y(XO4)n, wherein x, y and n are numbers such that 0≦
x≦
2, 0≦
y≦
0.6, and 1≦
n≦
1.5, M is a transition metal or a mixture of transition metals in the first line of the periodic table, M′
is an element with fixed valency selected from the group consisting of Mg2+, Ca2+, Al3+, Zn2+, and combinations thereof and X is S, P or Si, comprising;
bringing into equilibrium in a reaction medium, in the required proportions, a mixture comprising the following precursors;
a) a source of M, wherein at least one part of the transition metal or metals that constitute M are in an oxidation state greater than that of the transition metal or metals in the final compound LixM1−
yM′
y(XO4)n;
b) a source of an element M′
;
c) a compound that is a source of lithium; and
optionally,d) a compound that is a source of X,wherein the sources of elements M, M′
, Li and X are introduced, in whole or in part, in the form of compounds having more than one source element, andwherein the synthesis is carried out by reaction and bringing into equilibrium, in the absence of carbon or in the presence of an amount of carbon insufficient or too inert kinetically to realize the reduction of a metal salt that constitutes M, in the proportions required, the mixture of the precursors a) to d) and by reduction, with a reducing gaseous atmosphere, to bring the transition metal or metals to the desired degree of valency.
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Accused Products
Abstract
Method of synthesis for a material made of particles having a core and a coating and/or being connected to each other by carbon cross-linking, the core of these particles containing at least one compound of formula LixM1−yM′y(XO4)n, in which x,y and n are numbers such as 0≦x≦2, 0≦y≦0.6 and 1≦n≦1.5, M is a transition metal, M′ is an element with fixed valency, and the synthesis is carried out by reaction and bringing into equilibrium the mixture of precursors, with a reducing gaseous atmosphere, in such a way as to bring the transition metal or metals to the desired valency level, the synthesis being carried out in the presence of a source of carbon called carbon conductor, which is subjected to pyrolysis. The materials obtained have excellent electrical conductivity as well as very improved chemical activity.
64 Citations
44 Claims
-
1. A method for the synthesis of a compound of the formula LixM1−
- yM′
y(XO4)n, wherein x, y and n are numbers such that 0≦
x≦
2, 0≦
y≦
0.6, and 1≦
n≦
1.5, M is a transition metal or a mixture of transition metals in the first line of the periodic table, M′
is an element with fixed valency selected from the group consisting of Mg2+, Ca2+, Al3+, Zn2+, and combinations thereof and X is S, P or Si, comprising;bringing into equilibrium in a reaction medium, in the required proportions, a mixture comprising the following precursors; a) a source of M, wherein at least one part of the transition metal or metals that constitute M are in an oxidation state greater than that of the transition metal or metals in the final compound LixM1−
yM′
y(XO4)n;b) a source of an element M′
;c) a compound that is a source of lithium; and
optionally,d) a compound that is a source of X, wherein the sources of elements M, M′
, Li and X are introduced, in whole or in part, in the form of compounds having more than one source element, andwherein the synthesis is carried out by reaction and bringing into equilibrium, in the absence of carbon or in the presence of an amount of carbon insufficient or too inert kinetically to realize the reduction of a metal salt that constitutes M, in the proportions required, the mixture of the precursors a) to d) and by reduction, with a reducing gaseous atmosphere, to bring the transition metal or metals to the desired degree of valency. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
- yM′
-
29. A method of synthesis of a material made of particles,
wherein the particles comprise a core and a coating and/or are connected to each other by cross-linking, wherein the core comprises at least one compound of the formula LixM1− - yM′
y(XO4)n, wherein x, y and n are numbers such that 0≦
x≦
2, 0≦
y≦
0.6, and 1≦
n≦
1.5, M is a transition metal or a mixture of transition metals from the first line of the periodic table, M′
is an element with fixed valency selected from the group consisting of Mg2+, Ca2+, Al3+, Zn2+ and combinations thereof and X is 5, P or Si, wherein the coating comprises carbon connecting at least two particles to each other, and wherein the cross-linking comprises carbon connecting at least two particles to each other, the method comprising bringing into equilibrium in a reaction medium, in the proportions required, a mixture comprising the following precursors;a) a source of M, wherein at least part of the transition metal or metals that constitute M are in an oxidation state greater than that of the metal in the final compound LixM1−
yM′
y(XO4)n;b) a source of an element M′
;c) a compound that is a source of lithium; and
optionally,d) a compound that is a source of X; wherein the sources of the elements M, M′
, Li and X are introduced, in whole or in part, in the form of compounds having more than one source element, andwherein the synthesis is carried out by reaction and bringing into equilibrium, in the absence of carbon or in the presence of an amount of carbon insufficient or too inert kinetically to realize the reduction of a metal salt that constitutes M, in the proportions required, the mixture of precursors a) to d) with a gaseous reducing atmosphere, in such a way as to bring the transition metal or metals to the desired degree of valency, wherein the synthesis is carried out in the presence of an organic substance as a source of carbon conductor, and wherein the synthesis leads to the material by a pyrolysis step for the carbon conductor after or simultaneously with preparing the mixture of the precursors and reduction of the mixture obtained. - View Dependent Claims (30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44)
- yM′
Specification