Phase-pure lithium aluminium titanium phosphate and method for its production and its use

Patent metadata

Field	Value
Publication number	US-9748557-B2
Application number	US-201514699255-A
Country	US
Kind code	B2
Filing date	Apr 29, 2015
Priority date	Oct 16, 2009
Publication date	Aug 29, 2017
Grant date	Aug 29, 2017

Abstract

The present invention relates to a method for producing lithium aluminum titanium phosphates of the general formula Li 1+x Ti 2−x Al x (PO 4 ) 3 , wherein x is ≦0.4, a method for their production as well as their use as solid-state electrolytes in lithium ion accumulators.

First claim

What is claimed:

1. A method for producing a phase-pure lithium aluminum titanium phosphate of the formula Li 1+x Ti 2−x Al x (PO 4 ) 3 comprising the steps of:
a) providing an aqueous liquid phosphoric acid,
b) adding a mixture of a lithium compound, titanium dioxide and an oxygen-containing aluminum compound to the aqueous phosphoric acid of step a),
c) heating the mixture of step b) in order to obtain a solid intermediate product, and
d) calcining the solid intermediate product of step c), wherein x is ≦0.4 and >0, and the concentration of magnetic metals and magnetic metal compounds of the elements Fe, Cr and Ni in the phase-pure lithium aluminum titanium phosphate is ≦1 ppm.

2. The method according to claim 1 , wherein the aqueous liquid phosphoric acid is aqueous liquid orthophosphoric acid.

3. The method according to claim 1 , wherein lithium carbonate is used as lithium compound.

4. The method according to claim 1 , wherein Al(OH) 3 is used as oxygen-containing aluminum compound.

5. The method according to claim 1 , wherein the step of heating is carried out at a temperature of from 200 to 300° C.

6. The method according to claim 5 , wherein the calcining takes place at a temperature in the range from 850° C. to 1000° C.

7. The method according to claim 6 , wherein the calcining is carried out over a period of from 5 to 24 hours.

8. The method according to claim 1 , wherein a stoichiometric excess of lithium compound is used in step b).

9. A method for producing a phase-pure lithium aluminum titanium phosphate of the formula Li 1+x Ti 2−x Al x (PO 4 ) 3 comprising the steps of:
a) providing 85% orthophosphoric acid,
b) adding a mixture of a lithium compound, titanium dioxide and an oxygen-containing aluminum compound to the 85% orthophosphoric acid of step a),
c) heating the mixture of step b) in order to obtain a solid intermediate product, and
d) calcining the solid intermediate product of step c),
wherein x is ≦0.4 and >0, and the concentration of magnetic metals and magnetic metal compounds of the elements Fe, Cr and Ni in the phase-pure lithium aluminum titanium phosphate is ≦1 ppm.

10. The method according to claim 9 , wherein lithium carbonate is used as lithium compound.

11. The method according to claim 9 , wherein Al(OH) 3 is used as oxygen-containing aluminum compound.

12. The method according to claim 9 , wherein the step of heating is carried out at a temperature of from 200 to 300° C.

13. The method according to claim 12 , wherein the calcining takes place at a temperature in the range from 850° C. to 1000° C.

14. The method according to claim 13 , wherein the calcining is carried out over a period of from 5 to 24 hours.

15. The method according to claim 9 , wherein a stoichiometric excess of lithium compound is used in step b).

Assignees

• Johnson Matthey Plc

Inventors

• Holzapfel Michael
• Eisgruber Max
• Nuspl Gerhard

Classifications

• H01M2004/028

  Positive electrodes · CPC title

• H01M4/136 Primary

  Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy · CPC title

• H01M4/5825

  Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines · CPC title

• H01M10/36 Primary

  Accumulators not provided for in groups H01M10/05-H01M10/34 · CPC title

• C01B25/45 Primary

  containing plural metal, or metal and ammonium · CPC title