Composition for a secondary battery cell

• US 9,608,272 B2
• Filed: 11/01/2011
• Issued: 03/28/2017
• Est. Priority Date: 05/11/2009
• Status: Active Grant

• Current Assignee: SK On Company Limited (SK Innovation Company Limited)
• Original Assignee: Nexeon Limited
• Inventors: Loveridge, Melanie J., Lain, Michael Jonathan, Coowar, Fazlil, Abdelsalam, Mamdouh Elsayed
• Primary Examiner(s): Gilliam, Barbara
• Assistant Examiner(s): MARTIN, ANGELA J
• Application Number:
  US13/286,864
• Publication Number:
  US 20120094178A1
• Time in Patent Office: 1,974 Days
• US Class Current: 1/1
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 4/134 Electrodes based on metals, Si or alloys
• CPC Class Codes: H01M 4/38 of elements or alloys
• CPC Class Codes: H01M 4/386 Silicon or alloys based on silicon
• CPC Class Codes: H01M 4/621 Binders
• CPC Class Codes: H01M 4/622 being polymers
• 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 29/49115 including coating or impregnating

Abstract

Composite electrode material for a rechargeable battery cell includes an electroactive material; and a polymeric binder including pendant carboxyl groups, characterized in that (i) the electroactive material includes one or more components selected from the group including an electroactive metal, an electroactive semi-metal, an electroactive ceramic material, an electroactive metalloid, an electroactive semi-conductor, an electroactive alloy of a metal, an electroactive alloy of a semi metal and an electroactive compound of a metal or a semi-metal, (ii) the polymeric binder has a molecular weight in the range 300,000 to 3,000,000 and (iii) 50 to 90% of the carboxyl groups of the polymeric binder are in the form of a metal ion carboxylate salt. A method of making a composite electrode material, an electrode, cells including electrodes and devices using such cells are also disclosed.

Claims

1. A composite electrode material for a rechargeable battery cell comprising:

a. an electroactive material; and

b. a polymeric binder including pendant metal ion carboxylate groups and pendant free carboxyl groups,

characterised in that (i) the electroactive material comprises one or more components selected from the group comprising an electroactive metal, an electroactive semi-metal, an electroactive ceramic material, an electroactive semi-conductor, and an electroactive compound of a metal or a semi-metal, (ii) the polymeric binder has a molecular weight in the range 300,000 to 3,000,000 and (iii) the ratio of the number of metal ion carboxylate groups of the polymeric binder to the sum of the number of metal ion carboxylate groups of the polymeric binder and free carboxyl groups of the polymeric binder is 0.50-0.90.

2. A composite electrode material according to claim 1, wherein the polymeric binder has a molecular weight in the range 400,000 to 2,000,000.

3. A composite electrode material according to claim 1, wherein the metal ion carboxylate salt is a carboxylate salt selected from the group comprising lithium, sodium, potassium and caesium.

4. A composite electrode material according to claim 1, which further comprises an electroactive carbon.

5. A composite electrode material according to claim 4, wherein the electroactive material and the electroactive carbon together comprise at least 50 wt % of the composite electrode material.

6. A composite electrode material according to claim 1, wherein the electroactive material comprises 15 to 90 wt % of the composite electrode material.

7. A composite electrode material according to claim 1, which comprises 0 to 70 wt % of an electroactive carbon.

8. A composite electrode material according to claim 1, wherein the polymeric binder comprises 3 to 40 wt % of the composite electrode material.

9. A composite electrode material according to claim 1, which further comprises a conductive carbon.

10. A composite electrode material according to claim 1, which further comprises a solvent.

11. A composite electrode material according to claim 10, which is an electrode mix.

12. A composite electrode material according to claim 10, in which the solvent is selected from the group comprising water, ethanol, propanol, polyvinylidinefluoride and polyvinyl alcohol.

13. A composite electrode material according to claim 1, wherein the electroactive material is selected from the group comprising silicon, tin, gallium, germanium, aluminium, lead, zinc, gold, silver, platinum, palladium, bismuth, arsenic, antimony, indium, mixtures thereof, alloys with non-electroactive metal and ceramic titanates (Ti₅O₁₂).

14. A composite electrode material according to claim 1, wherein the electroactive material is a structured electroactive material selected from one or more of the structure group comprising particles, elongate elements, pillared particles, porous particles, porous particle fragments, substrate particles, bundles of elongate elements, and scaffold structures.

15. A composite electrode material according to claim 1, wherein the electroactive material comprises a coated structure.

16. A composite electrode material according to claim 15, wherein the electroactive material comprises a core having one or more coating layers formed thereon.

17. A composite electrode material according to claim 16, in which the core is an electroactive material.

18. A composite electrode material according to claim 16, in which the one or more coating layers is an electroactive material.

19. A composite electrode material according to claim 1, wherein the electroactive material comprises silicon.

20. A composite electrode material according to claim 19, wherein the silicon has a purity in the range 95% to 99.999%.

21. A composite electrode material according to claim 19, wherein the silicon is a metallurgical grade silicon.

22. A composite electrode material according to claim 19, wherein the electroactive material comprises silicon comprising particles.

23. A composite electrode material according to claim 19, wherein the electroactive material comprises silicon comprising elongate elements.

24. A composite electrode material according to claim 19, wherein the electroactive material comprises structured silicon in the form of a silicon-comprising pillared particle.

25. A composite electrode material according to claim 19, wherein the electroactive material comprises structured silicon in the form of a silicon-comprising porous particle having a plurality of voids or channels extending there through.

26. A composite electrode material according to claim 19, wherein the electroactive material comprises structured silicon in the form of a silicon-comprising porous particle fragment having a minimum dimension of 50 nm to 100 nm.

27. An electrode for a rechargeable battery comprising a current collector and an electroactive material according to claim 1.

28. An electrode according to claim 27, wherein the electroactive material is formed, applied, adhered or bound as a coating layer to the current collector.

29. An electrode according to claim 27, which is an anode.

30. A method of manufacturing an electrode according to claim 27 which comprises the step of applying an electrode mix according to claim 11 to a current collector and drying the product.

31. A cell comprising an electrode according to claim 27, a cathode, a separator and an electrolyte.

32. A device comprising a cell according to claim 31.

33. The composite electrode material of claim 1, wherein the polymeric binder is a linear polymer.

34. A composite electrode material according to claim 33, wherein the linear binder polymer is poly(acrylic acid).

35. A composite electrode material according to claim 34, wherein the metal ion carboxylate salt is a sodium carboxylate salt.

36. A composite electrode material according to claim 1, wherein 60 to 80% of the carboxyl groups of the polymeric binder are in the form of a metal ion carboxylate salt.

37. A composite electrode material according to claim 1, wherein the number of pendant carboxyl groups of the polymeric binder is in the range of 50 to 100% of the total number of monomer units of the polymeric binder.

38. A composite electrode material according to claim 1, wherein

the metal ion carboxylate salt is a carboxylate salt selected from the group comprising lithium, sodium and potassium;

the electroactive material is a silicon-containing material having at least 90% silicon; and

the polymeric binder is a poly(acrylic acid).

39. A composite electrode material according to claim 38, wherein 60 to 80% of the carboxyl groups of the polymeric binder are in the form of a metal ion carboxylate salt.