Method of making non-aqueous electrochemical cell

• US 20070000121A1
• Filed: 09/06/2006
• Published: 01/04/2007
• Est. Priority Date: 02/28/2002
• Status: Active Grant

• Current Assignee: Duracell U.S. Operations, Inc. (Berkshire Hathaway Incorporated)
• Original Assignee: Gillette Company (The Procter & Gamble Company)
• Inventors: Pozin, Michael, Issaev, Nikolai, Bowden, William
• Granted Patent: US 7,566,350 B2
• Time in Patent Office: Days
• US Class Current: 29/623.100
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0568 characterised by the solutes
• CPC Class Codes: H01M 10/0569 characterised by the solvents
• CPC Class Codes: H01M 2300/0037 Mixture of solvents
• CPC Class Codes: H01M 6/164 by the solvent
• CPC Class Codes: H01M 6/166 by the solute
• 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
• CPC Class Codes: Y10T 29/49108 Electric battery cell making

Abstract

A lithium electrochemical cell includes an electrolyte having a mixture of solvents including propylene carbonate (PC) and dimethoxyethane (DME), and a salt mixture. The salt mixture includes lithium trifluoromethanesulfonate (LiTFS), and lithium trifluoromethanesulfonimide (LiTFSI), and the cell contains less than 1500 ppm by weight of sodium. The mixture of solvents can further include ethylene carbonate (EC).

Claims

1. A method of manufacturing a lithium electrochemical cell containing less than 1500 ppm by weight of sodium, the method comprising

(a) cleaning a case with a solution that does not contain sodium,

(b) providing a cathode, an anode, a separator, and an electrolyte comprising propylene carbonate, dimethoxyethane, lithium trifluoromethanesulfonate, and lithium trifluoromethanesulfonimide, these components having sufficiently low quantities of sodium that, when combined with the case, can provide a lithium electrochemical cell containing less than 1500 ppm by weight of sodium, and

(c) assembling the cathode, the anode, the separator, and the electrolyte from step (b) into the case from step (a) to provide a lithium electrochemical cell containing less than 1500 ppm by weight of sodium.

2. The method of claim 1, wherein the cathode includes electrolytic manganese dioxide that has been washed or neutralized after deposition with an agent that does not include sodium.

3. The method of claim 1, wherein the cathode includes electrolytic manganese dioxide that has been washed or neutralized after deposition with lithium hydroxide.

4. The method of claim 1, wherein the cell contains less than 1200 ppm by weight of sodium.

5. The method of claim 1, wherein the cell contains less than 1000 ppm by weight of sodium.

6. The method of claim 1, wherein the cell contains less than 800 ppm by weight of sodium.

7. The method of claim 1, wherein the cell contains less than 600 ppm by weight of sodium.

8. The method of claim 1, wherein the electrolyte comprises:

40-80% by weight of the dimethoxyethane,

20-60% by weight of the propylene carbonate, and

between 0.4 M and 1.2 M of the lithium trifluoromethanesulfonate and the lithium trifluoromethanesulfonimide combined.

9. A method of manufacturing a lithium electrochemical cell containing less than 1500 ppm by weight of sodium, the method comprising

(a) cleaning a case with a solution that does not contain sodium,

(b) providing a cathode, an anode, a separator, and an electrolyte comprising ethylene carbonate, propylene carbonate, dimethoxyethane, lithium trifluoromethanesulfonate, and lithium trifluoromethanesulfonimide, these components having sufficiently low quantities of sodium that, when combined with the case, can provide a lithium electrochemical cell containing less than 1500 ppm by weight of sodium, and

(c) assembling the cathode, the anode, the separator, and the electrolyte from step (b) into the case from step (a) to provide a lithium electrochemical cell containing less than 1500 ppm by weight of sodium.

10. The method of claim 9, wherein the cathode includes electrolytic manganese dioxide that has been washed or neutralized after deposition with an agent that does not include sodium.

11. The method of claim 9, wherein the cathode includes electrolytic manganese dioxide that has been washed or neutralized after deposition with lithium hydroxide.

12. The method of claim 9, wherein the cell contains less than 1200 ppm by weight of sodium.

13. The method of claim 9, wherein the cell contains less than 1000 ppm by weight of sodium.

14. The method of claim 9, wherein the cell contains less than 800 ppm by weight of sodium.

15. The cell of claim 9, wherein the cell contains less than 600 ppm by weight of sodium.

16. The method of claim 9, wherein the electrolyte comprises:

less than 30% by weight of ethylene carbonate,

40-85% by weight of dimethoxyethane, and

between 0.4 M and 1.2 M of the lithium trifluoromethanesulfonate and the lithium trifluoromethanesulfonimide combined.

17. The method of claim 16, wherein the electrolyte comprises:

10-20% by weight of ethylene carbonate;

50-70% by weight of dimethoxyethane.

18. The method of claim 16, wherein the electrolyte comprises:

5-15% by weight of ethylene carbonate;

70-80% by weight of dimethoxyethane; and

10-20% by weight of propylene carbonate.