Electroactive material for secondary batteries and methods of preparation

• US 6,599,662 B1
• Filed: 01/07/2000
• Issued: 07/29/2003
• Est. Priority Date: 01/08/1999
• Status: Expired due to Fees

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Ceder, Gerbrand, Limthongkul, Pimpa, Chiang, Yet-Ming
• Primary Examiner(s): Chaney, Carol
• Assistant Examiner(s): DOVE, TRACY MAE
• Application Number:
  US09/479,154
• Time in Patent Office: 1,299 Days
• Field of Search: 429/218.1, 429/231.1, 429/231.5, 429/231.9, 429/217
• US Class Current: 429/218.1
• CPC Class Codes: C01B 3/001 characterised by the uptaking medium; Treatment thereof
• CPC Class Codes: C01G 23/00 Compounds of titanium preparation of Ti-compounds from ores or scraps C22B34/12
• CPC Class Codes: C01G 3/00 Compounds of copper
• CPC Class Codes: C01G 31/00 Compounds of vanadium
• CPC Class Codes: C01G 37/00 Compounds of chromium
• CPC Class Codes: C01G 45/1221 Manganates or manganites with a manganese oxidation state of Mn(III), Mn(IV) or mixtures thereof
• CPC Class Codes: C01G 45/1235 of the type [Mn2O4]2-, e.g. Li2Mn2O4, Li2[MxMn2-x]O4
• CPC Class Codes: C01G 45/1242 of the type [Mn2O4]-, e.g. LiMn2O4, Li[MxMn2-x]O4
• CPC Class Codes: C01G 49/00 Compounds of iron
• CPC Class Codes: C01G 51/00 Compounds of cobalt
• CPC Class Codes: C01P 2002/32 spinel-type (AB2O4)
• CPC Class Codes: C01P 2002/34 perovskite-type (ABO3)
• CPC Class Codes: C01P 2002/50 Solid solutions
• CPC Class Codes: C01P 2002/72 by d-values or two theta-values, e.g. as X-ray diagram
• CPC Class Codes: C01P 2004/03 obtained by SEM
• CPC Class Codes: C01P 2004/04 obtained by TEM, STEM, STM or AFM
• CPC Class Codes: C01P 2006/40 Electric properties
• CPC Class Codes: H01M 2004/027 Negative electrodes
• CPC Class Codes: H01M 4/36 Selection of substances as active materials, active masses, active liquids
• CPC Class Codes: H01M 4/364 as mixtures
• CPC Class Codes: H01M 4/383 : Hydrogen absorbing alloys
• 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: H01M 6/40 : Printed batteries , e.g. thin film batteries
• CPC Class Codes: Y02E 60/32 : Hydrogen storage

Abstract

This invention provides a composite material for use as an electrode in electrochemical devices. An electroactive composite material includes a first electroactive metal, the electroactive material including a phase enriched in a metal or metal alloy, Me^I, capable of intercalating or alloying with a species selected from the group consisting of alkali metals and hydrogen, and a second material having the first active material intimately mixed therein. The second material includes a metal oxide, Me_y^IIO_z, wherein the metals Me^I have a less negative Gibbs free energy for alloying or compound formation with oxygen than the metals that comprise Me^IIO. The materials of the invention comprise a first material that is an elemental metal, metal alloy, metal oxide, or other metal compound, selected so that it is able to alloy with lithium, and prepared in a dispersed one-, two- or three-dimensional form. The first material is intimately mixed with or dispersed within a second material that may be substantially conductive to electrons or electron holes or lithium ions. The composite material may be prepared by a process known as “partial reduction” or “internal reduction,” in which a precursor to the first material is preferentially reduced, or the process known as “partial oxidation,” in which a precursor to the second material is preferentially oxidized.

Claims

1. A composite material for use as an energy-storage material comprising,

a first material comprising one or more metals, metal alloys or metal compounds containing Me^I capable of alloying with a species selected from the group consisting of alkali metals and hydrogen, the first material intimately mixed with a matrix of a second material comprising a metal compound Me^IIX,

produced by partial reduction of a mixed-metal composition Me^I_aMe^II₁₋

aX_z, where 0.1<

a<

0.9, z>

0, and X is one of oxygen, boron, carbon, nitrogen, phosphorus, fluorine, chlorine, bromine, or iodine, under conditions that preferentially reduce Me^I over Me^II.

3. The composite material of claim 1 or 2, wherein the mixed-metal composition is a solid solution.

4. The composite material of claim 1 or 2, wherein the mixed-metal composition is a phase-separated composition, which is phase-separated into a first phase comprising compounds rich in Me^I and a second phase comprising compounds rich in Me^II.

5. The material of claim 1 or 2, wherein the mixed-metal composition is a mixture of particles of different composition.

6. The composite material of claim 1 or 2, wherein the second material comprises a compound Me^II_cX_d where 0.5<

c/d<

3.

7. The material of claims 1 or 2, wherein Me^I as part of the first material has a lower molar volume than Me^I as part of the mixed-metal composition.

8. The material of claim 1, wherein both the first material and the second material have a reduced molar volume compared to the mixed-metal composition, and the first material undergoes a greater molar volume decrease than does the second material during partial reduction.

10. The material of claim 1 or 2, wherein X is oxygen and Me^II comprises one or more metals selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Nb, Mo, Ru and Ce.

11. The material of claim 10, wherein Me^II comprises one or more metals in an amount in the range of about 10-90 mole % of the mixed-metal composition.

12. The material of claim 11, wherein Me^II comprises one or more metals in an amount greater than about 50 mole % of the mixed-metal composition.

13. The material of claim 10, wherein Me^II comprises one or more metals in an amount greater than about 75 mole % of the mixed-metal composition.

14. The material of claim 1, wherein X is oxygen and the mixed-metal composition Me^I_aMe^II₁₋

aX_z has a crystalline structure selected from the group consisting of the spinel structure, the rocksalt structure, the rutile structure, the corundum structure, the ilmenite structure, the perovskite structure and ordered or disordered derivatives of these structures.

15. The material of either of claims 1 or 2, wherein X is oxygen and the second material comprises a normal spinel, inverse spinel, or disordered spinel structure compound Me^II_cX_d where 0.5<

c/d<

1.

16. The material of claim 14, wherein the second material remaining after partial reduction is a compound Me^II_xO_y, where 0.5<

x/y<

1, having a crystalline structure selected from the group consisting of rutile, corundum, ilmenite, perovskite and ordered or disordered derivatives of these structures.

17. The material of claim 1 or 2, wherein X is oxygen and Me^I is selected from the group consisting of Ag, Sb, Sn, Cu, In, Ge, Zn, Ga, B, and Si.

18. The material of claim 1 or 2, wherein X is oxygen and Me^I is selected from the group consisting of Ag, Sb, Zn and Sn.

19. The material of claim 17, wherein Me^II is selected from the group consisting of Cu, Mn, Sb, Ni, Co, Fe, In, Ge, Zn, Ga, Cr, V, B, Si, Ti, Ta, Nb, Ru, Ce, Al and Mg, and wherein Me^II is further selected to have a more negative Gibbs free energy of metal oxide formation than Me^I.

20. The material of claim 1 or 2, wherein the mixed metal composition comprises Me^I_aMn₁₋

aO<sub>4/3−

y</sub> spinel, x being between about 0.17 and 0.67 and y being between zero and about 0.17, and the metal Me^I, selected from the group consisting of Ag, Sb, Zn, and Sn.

21. The material of claim 1 or 2, wherein the mixed-metal composition has formula Me^I_aMe^II₁₋

aX_z, X is oxygen, Me^I is Ag, Me^II is Mn, and 0.1<

a<

0.9, and 1.9<

z<

2.1.

22. The material of claim 1 or 2, wherein the mixed metal composition has formula Me^I_aMe^II₁₋

aX_z, X is oxygen, Me^I is Sb, Me^II is Mn, and 0.1<

a<

0.9, and 1.9<

z<

2.1.

23. The material of claim 1 or 2, wherein the mixed metal composition has formula Me^I_aMe^II₁₋

aX_z, X is oxygen, Me^I is Zn, Me^II is Mn, and 0.1<

a<

0.9, and 1.9<

z<

2.1.

24. The material of claim 1 or 2, wherein the mixed-metal composition has the formula Me^I_aMe^II₁₋

aO_z, where Me^I is Sb;

Me^II is V, and 0.1<

a<

0.9, and 1.9<

z<

2.3.

25. The material of claim 1 or 2, where in the mixed-metal composition has the formula Me^I_bMe^II₁₋

bO_e, where Me^I is Sn, Me^II is Ti, and 0.2<

b<

0.8, and 1.8<

e<

2.2.

28. The composite material of claim 1, 2, 26 or 27, wherein the alloying species is lithium.

41. The material of claim 1, 2, 26 or 27, wherein the first material is present in a dispersed form intimately mixed with or contained within the second material, the first material forming a plurality of particles, rods, nets, sheets, or a combination of such morphologies.

42. The material of claim 41, in which the first material has an average smallest dimension of less than 10 micrometers and greater than 5 micrometers.

43. The material of claim 41, in which the first material has an average smallest dimension of less than 5 micrometers and greater than 1 micrometers.

44. The material of claim 41, in which the first material has an average smallest dimension of less than 1 micrometer and greater than 0.1 micrometer.

45. The material of claim 41, in which the first material has an average smallest dimension of less than 0.1 micrometer.

46. The material of claim 1, 2, 26 or 27, wherein the second material is substantially conductive to electrons, electron holes or lithium ions.

47. The material of claim 1 or 2, wherein the mixed metal oxide composition is mechanically worked prior to partial oxidation or reduction.

2. A composite material for use as an energy-storage material comprising,

a first material comprising one or more metals, metal alloys or metal compounds containing Me^I capable of alloying with a species selected from the group consisting of alkali metals and hydrogen, the first material intimately mixed with a matrix of a second material comprising a metal compound Me^IIX,

produced by partial oxidation of a mixed-metal composition Me^I_aMe^II₁₋

aX_z, where 0.1<

a<

0.9, z>

0, and X is one of oxygen, boron, carbon, nitrogen, phosphorus, fluorine, chlorine, bromine, or iodine, or a starting mixed-metal alloy Me^I_aMe^II<sub>1−

a</sub>, where 0.1<

a<

0.9 under conditions that preferentially oxidize Me^II over Me^I.

9. The material of claim 2, wherein both the first material and the second material have an increased molar volume compared to the mixed-metal composition, and the second material undergoes a greater molar volume increase than does the first material during partial oxidation.

26. An electroactive composite material, comprising:

a first electroactive material, said electroactive material comprising Me^I capable of alloying with a species selected from the group consisting of alkali metals and hydrogen; and

a second material having the first active material intimately mixed therein, said second material comprising Me_c^IIX_d, where 0.5<

c/d<

3 and X is one of oxygen, boron, carbon, nitrogen, phosphorus, fluorine, chlorine, bromine, or iodine,

wherein the first material is in a state of tensile stress or the composite has void space in its interior.

29. The composite material of claim 26, wherein the second material comprises a compound Me^II_cX_d where 0.5<

c/d<

3.

30. The composite material of claims 26 or 27, wherein Me^I as part of the first material has a lower molar volume than Me^I as part of the mixed-metal composition.

31. The composite material of claim 26, wherein Me^I has a less negative Gibbs free energy for alloying or compound formation with oxygen than the metals that comprise Me^IIO.

32. The material of claims 26 or 27, wherein Me^II comprises one or more metals selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Nb, Mo, Ru and Ce.

33. The material of claim 32, wherein Me^II comprises one or more metals in an amount in the range of about 10-90 mole % of the electroactive composite material.

34. The material of claim 32, wherein Me^II comprises one or more metals in an amount greater than about 50 mole % of the electroactive composite material.

35. The material of claim 32, wherein Me^II comprises one or more metals in an amount greater than about 75 mole % of the electroactive composite material.

40. The material of claim 26 or 27, wherein Me^II is selected from the group consisting of Cu, Mn, Sb, Ni, Co, Fe, In, Ge, Zn, Ga, Cr, V, B, Si, Ti, Ta, Nb, Ru, Ce, Al and Mg, and wherein Me^II, is further selected to have a more negative Gibbs free energy of metal oxide formation than Me^I.

27. An electroactive composite material, comprising:

a first electroactive metal, said electroactive material comprising a phase enriched in a metal or metal alloy, Me^I, capable of alloying with a species selected from the group consisting of alkali metals and hydrogen; and

a second material having the first active material intimately mixed therein, said second material comprising a metal oxide, Me_y^IIO_z, where 0.5<

y/z<

3, wherein Me^I has a less negative Gibbs free energy for alloying or compound formation with oxygen than the metals that comprise Me^IIO.

36. The material of claim 27, wherein the second material is a normal spinel, inverse spinel, or disordered spinel structure compound Me^II_xO_y where 0.5<

x/y<

1.

37. The material of claim 27, wherein the second material is a compound Me^II_xO_y, where 0.5<

x/y<

1, having a crystalline structure selected from the group consisting of rutile, corundum, ilmenite, perovskite and ordered or disordered derivatives of these structures.

38. The material of claim 27, wherein Me^I is selected from the group consisting of Ag, Sb, Sn, Cu, In, Ge, Zn, Ga, B, and Si.

39. The material of claim 27, wherein Me^I is selected from the group consisting of Ag, Sb and Sn.

48. An electrode for a lithium battery, comprising:

a first electroactive material comprising a phase enriched in a metal or metal alloy, Me^I, capable of alloying with lithium; and

a second material having the first electroactive material intimately mixed therein, said second material comprising a metal oxide, Me_y^IIO_z, where 0.5<

y/z<

3,

wherein Me^I has a less negative Gibbs free energy for alloying or compound formation with oxygen than the metals that comprise Me^IIO.

49. The electrode of claim 48, further comprising an organic binder.

50. The electrode of claim 48, further comprising a conductive carbon powder.

52. A thin-film battery using the electrode of claim 48.

51. A lithium battery, comprising;

a cathode;

an anode comprised of a first electroactive material comprising a phase enriched in a metal or metal alloy, Me^I, capable of alloying with a species selected from the group consisting of alkali metals and hydrogen; and

a second material having the first electroactive material intimately mixed therein, said second material comprising a metal oxide, Me_y^IIO_z, where 0.5<

y/z<

3, wherein Me^I has a less negative Gibbs free energy for alloying or compound formation with oxygen than the metals that comprise Me^IIO; and

an electrolyte in ionic and electrical contact with the anode and cathode.