Fluorosulphates useful as electrode materials

Patent metadata

Field	Value
Publication number	US-9293767-B2
Application number	US-200913124723-A
Country	US
Kind code	B2
Filing date	Oct 23, 2009
Priority date	Oct 23, 2008
Publication date	Mar 22, 2016
Grant date	Mar 22, 2016

Abstract

A material is made up of particles of an optionally-doped fluorosulphate. The fluorosulphate has a distorted Tavorite type structure of formula (A 1−a A′ a )x(Z 1−b Z′ b )z(SO 4 ) s F f (I) where A=Li or Na, A′ 0 a hole or at least one doping element, Z=at least one element selected from Fe, Co and Ni, Z′=a hole or at least one doping element, the indices a, b, x, z, s, and f are selected to assure the electroneutrality of the compound and a≧0, b≧0, x≧0, z>0, s>0, f>0, the respective quantities a and b of dopant A and Z′ being such that the Tavorite type structure is preserved. The material is obtained from the precursors thereof by an ionothermal route or ceramic route in a closed reactor. The material is of particular use as an active electrode material.

First claim

The invention claimed is:

1. A process for preparing a material, having particles of a fluorinated compound which has a distorted tavorite structure and which corresponds to the following formula (I):
(A 1−a A′ a ) x (Z 1−b Z′ b ) z (SO 4 ) s F f   (I)

in which
A represents Li or Na;
A′ represents a vacancy or at least one dopant element;
Z represents at least one element chosen from Fe, Co and Ni;
Z′ represents a vacancy or at least one dopant element;
the indices a, b, x, z, s, and f are chosen so as to ensure the etectroneutrality of the compound, and 1≧a≧0, 1>b≧0, x≧0, z>0, s>0, f>0;
the respective amounts a and b of dopant A and Z′ are such that the tavorite structure is preserved, wherein said method comprises the steps of:

dispersing precursors of the elements which form said material of formula (I) in a support liquid comprising at least one ionic liquid consisting of a cation and of an anion, the electric charges of which are balanced, in order to obtain a suspension of said precursors in said liquid;
ii) heating said suspension to a temperature of 25 to 330° C.;
iii) separating said ionic liquid and the material of formula (I) resulting from the reaction between said precursors.

2. The process as claimed in claim 1 , wherein the amount of precursors present within the ionic liquid during step i) is from 0.01% to 85% by weight.

3. The process as claimed in claim 1 , wherein the precursor of A or A′ is chosen from inorganic acid salts, volatile organic acid salts, heat-decomposable acid salts, fluorides and sulfates.

4. The process as claimed in claim 1 , wherein the precursor of a Z or Z′ element is chosen from the sulfates of Z or of Z′ that have a tavorite structure.

5. The process as claimed in claim 1 , wherein the precursor of Z and, where appropriate, of Z′ is a monohydrate ZSO 4 .H 2 O or Z′SO 4 .H 2 O or a mixed monohydrate Z 1−b Z′ b SO 4 .H 2 O, and the precursor of A and, where appropriate, of A′ is a fluoride.

6. The process as claimed in claim 5 , wherein an excess of fluoride of 5% to 25% is used.

7. The process as claimed in claim 1 , wherein the ionic liquid is 1-butyl-3-methylimidazolium trifluoromethanesulfonate or 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide.

8. The process as claimed in claim 1 , wherein the heating step ii) is carried out under an inert atmosphere, at atmospheric pressure.

9. The process as claimed in claim 1 , wherein A′ is an alkali et different from A, an alkaline-earth metal or a 3d metal.

10. The process as claimed in claim 1 , wherein Z′ is a metal chosen from alkali metals, Mn, Mg, Ca, Sc, Ti, V, Cr, Zn, Al, Ga, Sn, Zr, Nb and Ta in at least one of their degrees of oxidation.

11. The process as claimed in claim 1 , wherein said material corresponds to one of the formulae Li(Z 1−b Z′ b ) z SO 4 F and Na(Z 1−b Z′ b ) z SO 4 F.

12. The process as claimed in claim 1 , wherein said material corresponds to the formula (Z 1−b Z′ b ) z (SO 4 ) s F f .

Assignees

• Tarascon Jean-Marie
• Recham Nadir
• Armand Michel
• Centre Nat Rech Scient
• Univ Picardie

Inventors

• Tarascon Jean-Marie
• Recham Nadir
• Armand Michel

Classifications

• C01G53/82

  Compounds containing nickel, with or without oxygen or hydrogen, and containing two or more other elements · CPC title

• C01G51/82

  Compounds containing cobalt, with or without oxygen or hydrogen, and containing two or more other elements · CPC title

• C01P2002/88

  by thermal analysis data, e.g. TGA, DTA, DSC · CPC title

• C01G51/006

  Chemistry & Metallurgy · mapped topic

• C01P2002/77

  by unit-cell parameters, atom positions or structure diagrams · CPC title