Alkaline rechargeable battery and process for the production thereof

• US 20020197530A1
• Filed: 03/08/2002
• Published: 12/26/2002
• Est. Priority Date: 03/09/2001
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Tani, Atsushi, Kawakami, Soichiro
• Granted Patent: US 6,902,845 B2
• Time in Patent Office: Days
• US Class Current: 429/218.2
• CPC Class Codes: H01M 10/345 Gastight metal hydride accumulators
• CPC Class Codes: H01M 4/02 Electrodes composed of, or comprising, active material
• CPC Class Codes: H01M 4/0416 involving impregnation with a solution, dispersion, paste or dry powder H01M4/0438 takes precedence
• CPC Class Codes: H01M 4/242 Hydrogen storage electrodes
• CPC Class Codes: H01M 4/383 Hydrogen absorbing alloys
• CPC Class Codes: H01M 4/48 of inorganic oxides or hydroxides
• 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

A rechargeable battery having an anode comprising a powdery composite material, said powdery composite material comprising a plurality of powdery composites having a structure comprising a core whose surface is covered by a coat layer, said core comprising an alloy particle of an alloy capable of reversibly storing and releasing hydrogen as a main component, said alloy containing at least one kind of a metal element selected from the group consisting of Zr, Ti and V as a main constituent element, and said coat layer comprising a hydrous oxide (including a hydroxide) of a metal element having an affinity with oxygen which is greater than that of any of said metal elements as the main constituent element of said alloy.

Claims

1. A rechargeable battery comprising an anode, a cathode, a separator and an alkali electrolyte solution, characterized in that said anode comprises an active material comprising a powdery composite material, said powdery composite material comprising a plurality of powdery composites having a structure comprising a core whose surface is covered by a coat layer, said core comprising an alloy particle of an alloy (a) capable of reversibly storing and releasing hydrogen as a main component, said alloy (a) containing at least one kind of a metal element (a-i) selected from the group consisting of Zr, Ti and V as a main constituent element, and said coat layer comprising a hydrous oxide (including a hydroxide) of a metal (b) element having an affinity with oxygen which is greater than that of any of said metal elements (a-i) as the main constituent element of said alloy.

2. A rechargeable battery according to claim 1, wherein said coat layer comprising said hydrous oxide (including said hydroxide) has particles of a metal or a metal compound having a catalyst function to make hydrogen to be in an active state such that said particles are dispersed in the inside or/and in the surface region of said coat layer.

3. A rechargeable battery according to claim 1, wherein said element to constitute said hydrous oxide (including said hydroxide) comprises at least one kind of a metal element selected from the group consisting of alkaline earth metals and Al.

4. A rechargeable battery according to claim 3, wherein said alkaline earth metal comprises at least one kind of a metal element selected from Mg and Ca.

5. A rechargeable battery according to claim 3, wherein said element to constitute said hydrous oxide (including said hydroxide) comprises at least Al or Al and Mg.

6. A rechargeable battery according to claim 5, wherein said element to constitute said hydrous oxide (including said hydroxide) further comprises Si or Li.

7. A rechargeable battery according to claim 1, wherein said hydrous oxide (including said hydroxide) is contained in an amount in a range of from 0.2 to 20 wt. % versus the total weight of said powdery composite material.

8. A rechargeable battery according to claim 7, wherein said hydrous oxide (including said hydroxide) is contained in an amount in a range of from 0.5 to 10 wt. % versus the total weight of said powdery composite material.

9. A rechargeable battery according to claim 1, wherein said coat layer has a thickness in a range of from 5 nm to 1.0 μ

m.

10. A rechargeable battery according to claim 9, wherein said coat layer has a thickness in a range of from 10 nm to 0.5 μ

m.

11. A rechargeable battery according to claim 1, wherein said hydrous oxide (including said hydroxide) contains amorphous phase.

12. A rechargeable battery according to claim 2, wherein said metal having a catalyst function to make hydrogen to be in an active state comprises at least one kind of a metal selected from the group consisting of Ni, Pd, Pt, Co, Fe, Rh, Ru, Ir, Cr, Mo, W, Ta, and Cu.

13. A rechargeable battery according to claim 12, wherein said metal having a catalyst function to make hydrogen to be in an active state comprises at least one kind of a metal selected from the group consisting of Ni, Pd, Pt, and Cu.

14. A rechargeable battery according to claim 2, wherein said metal compound having a catalyst function to make hydrogen to be in an active state comprises at least one kind of a metal compound selected from the group consisting of nickel oxide, cobalt oxide, chromium oxide, molybdenum oxide, copper oxide, zinc oxide, molybdenum carbide, and tungsten carbide.

15. A rechargeable battery according to claim 2, wherein said metal or said metal compound having a catalyst function to make hydrogen to be in an active state is contained in an amount in a range of from 0.5 to 10 wt. % versus the total weight of the powdery composite material including said metal or said metal compound.

16. A rechargeable battery according to claim 1, wherein said coat layer comprising said hydrous oxide (including said hydroxide) further have a carbon powder such that said carbon powder is dispersed in the inside or/and in the surface region of the coat layer.

17. A rechargeable battery according to claim 1, wherein said alloy capable of reversibly storing and releasing hydrogen further contains at least Ni as other constituent element.

18. A rechargeable battery according to claim 1, wherein said alloy capable of reversibly storing and releasing hydrogen further contains at least one kind of a metal element selected from the group consisting of Co, Fe, Mn, Cr, Mo, W, Nb, Ta, Hf, Cu, and Zn as other constituent element.

19. A rechargeable battery according to claim 17, wherein said alloy capable of reversibly storing and releasing hydrogen further contains at least one kind of a metal element selected from the group consisting of Co, Fe, Mn, Cr, Mo, W, Nb, Ta, Hf, Cu, and Zn as other constituent element.

20. A rechargeable battery according to claim 1, wherein said alloy capable of reversibly storing and releasing hydrogen is a Laves phase-bearing alloy selected from the group consisting of Laves phase-bearing Cl4(MgZn₂) type alloys, and Laves phase-bearing Cl5(MgCu₂) type alloys.

21. A rechargeable battery according to claim 1, wherein said alloy capable of reversibly storing and releasing hydrogen is a body-centered cubic structure-bearing solid solution alloy.

22. A rechargeable battery according to claim 1, wherein said alloy particle of said alloy which constitutes said core comprises a particle shaped in an indefinite form with an irregular surface and having an average particle size in a range of from 0.5 to 30 μ

m.

23. A rechargeable battery according to claim 1, wherein said alloy capable of reversibly storing and releasing hydrogen contains amorphous phase.

24. A rechargeable battery according to claim 1, wherein said anode comprises an active material layer comprising at least said powdery composite material and a collector selected from the group consisting of a punching metal, an expanded metal and a metal foil, respectively comprising a nickel or a nickel-plated metal.

25. A rechargeable battery according to claim 24, wherein said active material layer is formed by bonding said powdery composite material on said collector together with a binder.

26. A rechargeable battery according to claim 24, wherein said active material layer is formed by sintering between particles of said powdery composite material and between said powdery composite material and said collector.

27. A rechargeable battery according to claim 24 wherein said cathode principally comprises a nickel hydroxide powder.

29. The process according to claim 28, wherein said second step (2) includes an additional step of dispersing particles of a metal or a metal compound having a catalyst function to make hydrogen to be in an active state such that said particles are dispersed in the inside or/and in the surface region of said coat layer.

30. The process according to claim 28, wherein said step (2) comprises a step (A) of coating the surface of said alloy powder (a-i) by said metal (b) to obtain a powdery composite material, and a step (B) of reacting said powdery composite material comprising said alloy powder (a-i) coated by said metal (b) with water or an aqueous alkali solution to convert said metal coated on the surface of said alloy powder to form said hydrous oxide (including said hydroxide) as said coat layer.

31. The process according to claim 30, wherein said step (A) comprises a first step of mixing said alloy powder (a-i) and a powder of said metal (b) to obtain a mixture and a second step of applying a mechanical energy to said mixture.

32. The process according claim 31, wherein the application of said mechanical energy to said mixture is performed by means of a grinding apparatus selected from the group consisting of tumbling ball mill, planetary ball mill, and vibration ball mill.

33. The process according to claim 30, wherein said step (A) comprises a first step of depositing, on the surface of the alloy powder (a-i), a particulate of said metal (b) is deposited so as to cover the surface of the alloy powder to obtain a powdery composite material comprising the alloy powder (a-i) whose surface is deposited with said particulate of the metal (b), and a second step of subjecting said powdery composite material to a heat treatment at a temperature which is lower than a sintering temperature at which said powdery composite material is sintered or/and to an alkali treatment.

34. The process according to claim 3, wherein the deposition of the particulate of the metal (b) is performed by means of a vacuum deposition technique selected from the group consisting of electron beam deposition, resistance heating deposition, sputtering, plasma CVD, and laser-assisted CVD.

35. The process according to claim 30, wherein the step (B) is performed by a method of preparing an assembly comprising the anode comprising the powdery composite material obtained in the step (A), the separator and the cathode, inserting the assembly in a battery housing, and introducing an aqueous alkali electrolyte solution comprising an alkali electrolyte dissolved in water into the battery housing, whereby the metal (b) coated on the surface of the alloy powder is reacted with said aqueous alkali electrolyte solution to form said hydrous oxide (including said hydroxide) as said coat layer.

36. The process according to claim 29, wherein the step dispersing the particles of the metal or the metal compound having a catalyst function to make hydrogen to be in an active state is performed at the same time of forming the coat layer, after the coat layer is formed, or at the same time off forming the coat layer and after the coat layer is formed.

37. The process according to claim 36, wherein the step dispersing the particles of the metal or the metal compound having a catalyst function to make hydrogen to be in an active state is performed by mixing a powder of the metal or the metal compound having a catalyst function to make hydrogen to be in an active state together with the alloy powder (a-i) and a powder of the metal (b) to obtain a mixture and applying mechanical energy to said mixture.

38. The process according to claim 37, wherein the application of the mechanical energy to the mixture is performed by means of a grinding apparatus selected from the group consisting of tumbling ball mill, planetary ball mill, and vibration ball mill.

39. The process according to claim 36, wherein the step dispersing the particles of the metal or the metal compound having a catalyst function to make hydrogen to be in an active state is performed by depositing a salt of said metal on the surface of the powdery composite material and reducing said salt.

40. The process according to claim 36, wherein the step dispersing the particles of the metal or the metal compound having a catalyst function to make hydrogen to be in an active state is performed by means of electroless plating or electroplating.

41. The process according to claim 36, wherein the step dispersing the particles of the metal or the metal compound having a catalyst function to make hydrogen to be in an active state is performed by means of a vacuum deposition technique.

42. The process according to claim 41, wherein the vacuum deposition technique is selected from the group consisting of electron beam deposition, resistance heating deposition, sputtering, plasma CVD, and laser-assisted CVD.

43. The process according to claim 28, wherein as the metal (b), at least one kind of a metal selected from the group consisting of alkaline earth metals and Al is used.

44. The process according to claim 43, wherein said alkaline earth metal, at least one kind of a metal selected from Mg and Ca is used.

45. The process according to claim 43, wherein as the metal (b), at least Al or Al and Mg are used.

46. The process according to claim 28, wherein as the metal (b), Si or Li is additionally used.

47. The process according to claim 28, wherein the content of said hydrous oxide (including said hydroxide) is made to fall in a range of from 0.2 to 20 wt. % versus the total weight of said powdery composite material.

48. The process according to claim 47, wherein the content of said hydrous oxide (including said hydroxide) is made to fall in a range of from 0.5 to 10 wt. % versus the total weight of said powdery composite material.

49. The process according to claim 28, wherein the thickness of the coat layer is made to fall in a range of from 5 nm to 1.0 μ

m.

50. The process according to claim 49, wherein the thickness of the coat layer is made to fall in a range of from 10 nm to 0.5 μ

m.

51. The process according to claim 29, wherein as the metal having a catalyst function to make hydrogen to be in an active state, at least one kind of a metal selected from the group consisting of Ni, Pd, Pt, Co, Fe, Rh, Ru, Ir, Cr, Mo, W, Ta, and Cu is used.

52. The process according to 51, wherein as the metal having a catalyst function to make hydrogen to be in an active state, at least one kind of a metal selected from the group consisting of Ni, Pd, Pt, and Cu is used.

53. The process according to claim 29, wherein as the metal compound having a catalyst function to make hydrogen to be in an active state, at least one kind of a metal compound selected from the group consisting of nickel oxide, chromium oxide, cobalt oxide, molybdenum oxide, copper oxide, zinc oxide, molybdenum carbide, and tungsten carbide is used.

54. The process according to claim 29, wherein the content of the metal or the metal compound having a catalyst function to make hydrogen to be in an active state is made to fall in a range of from 0.5 to 10 wt. % versus the total weight of the powdery composite material including said metal or said metal compound.

55. The process according to claim 28, wherein a carbon powder is further dispersed such that said carbon powder is dispersed in the inside or/and in the surface region of the coat layer.

57. The process according to claim 28, wherein the alloy (a) further contains at least one kind of a metal element selected from the group consisting of Co, Fe, Mn, Cr, Mo, W, Nb, Ta, Hf, Cu, and Zn as other constituent element.

58. The process according to claim 56, wherein the alloy (a) further contains at least one kind of a metal element selected from the group consisting of Co, Fe, Mn, Cr, Mo, W, Nb, Ta, Hf, Cu, and Zn as other constituent element.

59. The process according to claim 28, wherein the alloy (a) is a Laves phase-bearing alloy selected from the group consisting of Laves phase-bearing Cl4(MgZn₂) type alloys, and Laves phase-bearing Cl5(MgCu₂) type alloys.

60. The process according to claim 28, wherein the alloy (a) is a body-centered cubic structure-bearing solid solution alloy.

61. The process according to claim 28 which further includes a step of forming said anode by bonding an active material layer comprising at least said powdery composite material on a collector selected from the group consisting of a punching metal, an expanded metal and a metal foil, respectively comprising a nickel or a nickel-plated metal.

62. The process according to claim 61, wherein to bond the active material layer to the collector is performed by mixing said powdery composite material with a solution containing a binder to obtain a paste and applying said paste on the collector.

63. The process according to claim 61, wherein to bond the active material layer to the collector is performed by sintering between particles of said powdery composite material and between said powdery composite material and the collector.

64. The process according to claim 28 which further includes a step of forming said cathode using a nickel hydroxide powder.

28. A process for producing a rechargeable battery comprising an anode, a cathode, a separator and an alkali electrolyte solution, characterized in that said process includes a step of forming said anode, comprising a first step (1) of providing an alloy powder (a-i) of an alloy (a) capable of reversibly storing and releasing hydrogen and which contains at least one kind of a metal element (a-ii) selected from the group consisting of Zr, Ti and V as a main constituent element, a second step (2) of forming, on the surface of said alloy powder (a-i), a coat layer comprising a hydrous oxide (including a hydroxide) of a metal (b) having an affinity with oxygen which is greater than that of any of said metal elements (a-ii) as the main constituent element of said alloy (a), to obtain a powdery composite material comprising a plurality of powdery composites having a structure comprising a core comprising an alloy particle of said alloy (a) and whose surface is covered by said coat layer, and a third step (3) of forming said anode using said powdery composite material.

56. The process according to 28, wherein the alloy (a) further contains at least Ni as other constituent element.