High capacity high rate materials

• US 5,674,642 A
• Filed: 06/02/1995
• Issued: 10/07/1997
• Est. Priority Date: 06/02/1995
• Status: Expired due to Fees

• Current Assignee: Regents of the University Minnesota, Regents of The University of Minnesota (University of Minnesota)
• Original Assignee: Regents of The University of Minnesota (University of Minnesota)
• Inventors: Le, Dinh Ba, Passerini, Stefano, Owens, Boone B., Smyrl, William H.
• Primary Examiner(s): NUZZOLILLO, MARIA
• Application Number:
  US08/460,492
• Time in Patent Office: 858 Days
• Field of Search: 429/218, 423/641, 423/646, 423/592, 423/594
• US Class Current: 429/231.2
• CPC Class Codes: C01G 31/00 Compounds of vanadium
• CPC Class Codes: C01G 31/02 Oxides
• CPC Class Codes: C01P 2002/20 Two-dimensional structures
• CPC Class Codes: C01P 2004/80 Particles consisting of a mixture of two or more inorganic phases
• CPC Class Codes: C01P 2006/12 Surface area
• CPC Class Codes: C01P 2006/40 Electric properties
• CPC Class Codes: C01P 2006/60 Optical properties, e.g. expressed in CIELAB-values
• CPC Class Codes: H01M 2004/023 Gel electrode
• CPC Class Codes: H01M 4/485 of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy H01M4/505, H01M4/525 take precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

Nominal composition V₂ O₄.5 (OH) materials suitable for intercalations of greater than 2.4 Li per V₂ O₅ to yield theoretical energy density of greater than 970 Wh/Kg of cathode active material, the intercalation being completely reversible and synthesis of the materials from sol and gels, and devices incorporating these materials.

Claims

1. A process for the preparation of intercalation materials of the nominal compound V₂ O₄.5 (OH) comprising:

providing an aqueous solution of V₂ O₅ networks progressively formed as a sol, then a gel to yield a precursor hydrogel and treating the precursor hydrogel to form;

(a) a cryogel of the nominal compound V₂ O₄.5 (OH) by freeze drying the precursor to the V₂ O₄.5 (OH) cryogel form;

or

(b) an aerogel of the nominal compound V₂ O₄.5 (OH) wherein said aerogel is made by super critically drying the precursor to the aerogel V₂ O₄.5 (OH) form.

2. The process of claim 1 wherein the film xerogel form is prepared with shear by means of spin coating, followed by a slow vacuum drying step.

3. The process of claim 1 wherein the film xerogel form is prepared with shear by means of dip coating, followed by a slow vacuum drying step.

4. The process of claim 1 wherein the film xerogel form is prepared with shear by spray coating, followed by a slow vacuum drying step.

5. The process of claim 1 wherein the film xerogel form is prepared with shear by doctor blading, followed by a slow vacuum drying step.

6. The process of claim 1 wherein the precursor hydrogel is treated by adding conductive particles to it prior to the formation of a composition comprising cryogel or aerogel and conductive particles.

7. The process of claim 6 wherein the particles are a form of carbon.

8. The process of claim 1 wherein the aerogel form is selected and the precursor hydrogel is converted to an organogel by replacing water with an organic solvent and is then supercritically dried by use of liquid CO₂ to the V₂ O₄.5 (OH) form, containing a chemically bound carbon.

9. The process of claim 8 wherein the organic solvent used to form the organogel is acetone.

10. The process of claim 8 wherein the organic solvent used to form the organogel is acetonitrile.

11. The process of claim 8 wherein the organic solvent is 1,4-dioxane.

12. The process of claim 1 wherein the cryogel form is selected and the precursor is freeze dried on a substrate.

13. The process of claim 1 wherein the cryogel form is selected and the precursor is freeze dried to a bulk powder.

14. The process of claim 1 wherein the aerogel form is selected and is formed on a substrate.

15. The process of claim 1 wherein the aerogel form is selected and is formed as a powder.

16. The process of claim 1 wherein the aerogel form is selected and the precursor is supercritically dried in a supporting structure.

17. The process of claim 16 wherein the supporting structure is graphite felt.

18. The process of claim 16 wherein the supporting structure is a conducting screen.

19. The process of claim 6 wherein the precursor is sonicated following the addition of the conductive particles.

20. The process of claim 19 wherein the sonicated precursor is formed into a coating on a substrate.

21. A new reversibly intercalated nominal compound Li_x V₂ O₄.5 (OH) where 2.4≦

X≦

4, in the form of an organogel, a cryogel or an aerogel.

22. A composition comprising the compound of claim 21 and conductive particles.

23. The composition of claim 22 wherein the particles are carbon.

24. A composition of matter comprising nominal compound V₂ O₄.5 (OH) aerogel including bound carbon resulting from an organic solvent used in the preparation of the aerogel.

25. The composition of claim 24 wherein the chemically bound carbon, is present in an amount of about 4% wt., bound water is present in an amount of about 4.5% wt., balance substantially V₂ O₅.

26. An aerogel having the formula nominal compound V₂ O₄.5 (OH) and a surface area in excess of about 300-450 m² /g.

27. An electrode including a quantity of nominal compound V₂ O₄.5 (OH) organogel, cryogel or aerogel characterized in that it is capable of intercalating lithium ions to the extent greater than 2.4 and up to 4 Li⁺ ions per unit of V₂ O₅.

28. The electrode of claim 27 wherein the organogel, cryogel or aerogel is in the form of a coating.

29. The electrode of claim 27 wherein the organogel, cryogel or aerogel is in the form of a powder mixed with other constituents.

30. The electrode of claim 29 wherein one of the other constituents is a quantity of conductive particles.

31. The electrode of claim 30 wherein the particles are a form of carbon.

32. The electrode of claim 29 wherein one of the other constituents is a binder.

33. The electrode of claim 27 in the form of a metal bronze.

34. A reversible electrode comprising an intercalated nominal compound Li_x V₂ O₄.5 (OH) wherein 2.4≦

X≦

4.

35. A battery comprising a lithium ion source anode and an opposing cathode comprising a material capable of reversibly intercalating lithium ions characterized in that the cathode material is selected from the group consisting of nominal compound V₂ O₄.5 (OH) organogels, cryogels and aerogels and has the capacity for reversibly intercalating at least 2.4 to 4 lithium ions per mole of V₂ O₅ in the cathode material.

36. A battery comprising a lithium ion source anode means and an opposing cathode comprising a material capable of reversibly intercalating lithium ions characterized in that the cathode material is selected from the group consisting of nominal compound V₂ O₄.5 (OH) organogels including bound carbon, nominal compound V₂ O₄.5 (OH) cryogels including bound carbon and nominal compound V₂ O₄.5 (OH) aerogels including bound carbon.

37. The battery of claim 36 wherein the cryogel or aerogel has a surface area in excess of about 300-450 m² /g.

38. A battery comprising a lithium ion source anode means and an opposing cathode comprising a material capable of reversibly intercalating lithium ions characterized in that the material is selected from the group consisting of V₂ O₄.5 (OH) organogels, cryogels and aerogels and provides a half cell reaction of x Li⁺ +V₂ O₄.5 (OH)+xe═

Li_x V₂ O₄.5 (OH) where 2.4≦

X≦

4.

39. The battery of claim 38 wherein an organogel or aerogel is selected and provides the battery with a higher volume potential as compared to the cryogel form.

40. A process for the preparation of intercalation materials of nominal compound V₂ O₄.5 (OH) comprising:

providing an aqueous solution of V₂ O₅ networks progressively formed as a sol, then a gel to yield a precursor hydrogel and treating the precursor hydrogel to form an organogel by replacing water with an organic solvent.

41. A new reversibly intercalated nominal compound Li_x V₂ O₄.5 (OH) where 2.4≦

X≦

4.