Synthesis of silver vanadium oxide for cathode material

• US 6,093,506 A
• Filed: 09/25/1998
• Issued: 07/25/2000
• Est. Priority Date: 02/03/1997
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Chen, Kaimin, Crespi, Ann M.
• Primary Examiner(s): Nuzzolillo, Maria
• Assistant Examiner(s): DOVE, TRACY MAE
• Application Number:
  US09/161,055
• Time in Patent Office: 669 Days
• Field of Search: 429/219, 429/231.2, 429/231.5, 423/592, 423/593
• US Class Current: 429/219
• CPC Class Codes: A61N 1/378 Electrical supply
• CPC Class Codes: C01G 31/00 Compounds of vanadium
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0587 of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
• CPC Class Codes: H01M 4/382 Lithium H01M4/405 takes precedence
• CPC Class Codes: H01M 4/48 of inorganic oxides or hydroxides
• CPC Class Codes: H01M 4/483 for non-aqueous cells H01M4/485 takes precedence
• CPC Class Codes: H01M 4/54 of silver
• CPC Class Codes: H01M 4/5825 Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines
• CPC Class Codes: H01M 50/109 of button or coin shape
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

This present invention provides a method for forming C-SVO without the need for flowing O₂ during its synthesis. A method of forming silver vanadium oxide in accordance with the present invention includes combining AgO with a vanadium-containing compound to form a mixture; and exposing the mixture to a sufficient temperature for a time effective to form silver vanadium oxide. A method of forming the silver vanadium oxide for use as a cathode material is disclosed.

Claims

1. A method of forming a cathode containing silver vanadium oxide cathode material, the method comprising the steps of:

combining AgO with a vanadium-containing compound to form a mixture;

heating the mixture to a temperature ranging between about 400 degrees Centigrade and about 600 degrees Centigrade for a period of time sufficient to form the silver vanadium oxide cathode material, and

including the silver vanadium oxide cathode material in a cathode for an electrochemical cell.

2. The method of claim 1, wherein the temperature is at least about 440 degrees Centigrade.

3. The method of claim 1, wherein the mixture is heated for at least about 1 hour.

4. The method of claim 1, wherein the mixture is heated for at least about 4 hours.

5. The method of claim 1, wherein the silver vanadium oxide cathode material included in the cathode has the formula Ag_x V₄ O_y, x being about 1.6 to about 2.2, and y being about 10.5 to about 11.5.

6. The method of claim 5, wherein y is about 11.

7. The method of claim 5, wherein x is about 2.

8. The method of claim 1, wherein the temperature of the heating step is no greater than about 550 degrees Centigrade.

9. The method of claim 1, wherein the temperature of the heating step ranges between about 480 degrees Centigrade and about 530 degrees Centigrade.

10. The method of claim 1, wherein the heating step further comprises the step of supplying a gas in a reaction chamber with the AgO and the vanadium-containing compound, the gas being selected from the group consisting of oxygen, nitrogen, argon, atmospheric air, and mixtures or combinations thereof.

11. The method of claim 1, wherein the step of combining AgO with a vanadium-containing compound further comprises the step of combining another compound from the group of Ag(0), Ag₂ O, and mixtures thereof, with the AgO and the vanadium-containing compound to form the mixture.

12. The method of claim 1, wherein the vanadium-containing compound of the combining step is selected from the group consisting of NH₄ VO₃, VO₂, V₂ O₃, V₂ O₅, V₂ O₄, V₃ O₇, V₄ O₉, V₆ O₁₃, and mixtures or combinations thereof.

13. The method of claim 1, wherein the silver vanadium oxide cathode material included in the cathode has an associated x-ray diffraction scan using Cu Kα

radiation having a peak occurring at a value of about 23.6°

(2θ

), indexed to a {002} lattice spacing, and a peak occurring at a value of about 24.0°

(2θ

), indexed to a {201} lattice spacing, when indexed on a C-centered unit cell.