Method for producing catalyst for air secondary battery, method for producing air secondary battery, catalyst for air secondary battery, and air secondary battery

Patent metadata

Field	Value
Publication number	US-11322751-B2
Application number	US-201916981275-A
Country	US
Kind code	B2
Filing date	Mar 25, 2019
Priority date	Mar 30, 2018
Publication date	May 3, 2022
Grant date	May 3, 2022

Abstract

A battery includes an electrode group including an air electrode and a negative electrode stacked with a separator therebetween, and an accommodating bag accommodating the electrode group along with an alkali electrolyte solution. The air electrode includes a catalyst for an air secondary battery. This catalyst for an air secondary battery is produced by a method for producing a catalyst for an air secondary battery, the method including a precursor preparation step of preparing a bismuth-ruthenium oxide precursor, a calcination step of calcining the bismuth-ruthenium oxide precursor obtained in this precursor preparation step to form a bismuth-ruthenium oxide, and a nitric acid treatment step of immersing the bismuth-ruthenium oxide obtained by this calcination step in a nitric acid aqueous solution.

First claim

The invention claimed is:

1. A method for producing a catalyst for an air secondary battery for use in an air electrode of the air secondary battery, the method comprising:
a precursor preparation step of preparing a pyrochlore-type oxide precursor,
a calcination step of calcining the pyrochlore-type oxide precursor to form a pyrochlore-type oxide, and
an acid treatment step of immersing the pyrochlore-type oxide obtained from the calcination step in an acidic aqueous solution to apply an acid treatment;
wherein the pyrochlore-type oxide is a pyrochlore-type bismuth-ruthenium oxide.

2. The method for producing a catalyst for an air secondary battery according to claim 1 , wherein the pyrochlore-type bismuth-ruthenium oxide has a composition represented by the general formula: Bi 2-X Ru 2-Y O 7-Z , wherein X, Y, and Z each represent a numerical value of 0 or more and 1 or less.

3. The method for producing a catalyst for an air secondary battery according to claim 1 , wherein the acidic aqueous solution is any of a nitric acid aqueous solution, a hydrochloric acid aqueous solution, or a sulfuric acid aqueous solution.

4. The method for producing a catalyst for an air secondary battery according to claim 2 , wherein the acid treatment is applied such that, when X represents the amount of bismuth contained in the bismuth-ruthenium oxide and Y represents the amount of ruthenium contained in the bismuth-ruthenium oxide, the value of X/Y, which is the ratio of the amount of bismuth to the amount of ruthenium, is 0.90 or less.

5. The method for producing a catalyst for an air secondary battery according to claim 4 , wherein the acid treatment is applied such that the value of X/Y, which is the ratio of the amount of bismuth to the amount of ruthenium, is 0.80 or more and 0.90 or less.

6. A method for producing an air secondary battery comprising:
an air electrode production step of allowing an air electrode substrate to carry an air electrode mixture comprising a catalyst for an air secondary battery to produce an air electrode,
a negative electrode production step of allowing a negative electrode substrate to carry a negative electrode mixture to produce a negative electrode,
an electrode group formation step of stacking the air electrode on the negative electrode with a separator therebetween to form an electrode group, and
an accommodation step of accommodating the electrode group along with an alkali electrolyte solution into a container,
wherein the catalyst for an air secondary battery is produced by the method for producing a catalyst for an air secondary battery according to claim 1 .

7. The method for producing an air secondary battery according to claim 6 , wherein the negative electrode production step further comprises a process of allowing the negative electrode mixture to contain a hydrogen storage alloy.

8. A catalyst for an air secondary battery for use in an air electrode of the air secondary battery, comprising a pyrochlore-type bismuth-ruthenium oxide that has been subjected to an acid treatment of immersion in an acidic aqueous solution and from which by-products generated in the production process have been removed.

9. The catalyst for an air secondary battery according to claim 8 , wherein the pyrochlore-type bismuth-ruthenium oxide has a composition represented by the general formula: Bi 2-x Ru 2-Y O 7-Z , wherein X, Y, and Z each represent a numerical value of 0 or more and 1 or less.

10. The catalyst for an air secondary battery according to claim 9 , wherein, in the bismuth-ruthenium oxide, when X represents the amount of bismuth contained in the bismuth-ruthenium oxide and Y represents the amount of ruthenium contained in the bismuth-ruthenium oxide, the value of X/Y, which is the ratio of the amount of bismuth to the amount of ruthenium, is 0.90 or less.

11. The catalyst for an air secondary battery according to claim 10 , wherein the value of X/Y, which is the ratio of the amount of bismuth to the amount of ruthenium, is 0.80 or more and 0.90 or less.

12. An air secondary battery comprising:
an electrode group comprising an air electrode and a negative electrode stacked with a separator therebetween, and
a container accommodating the electrode group along with an alkali electrolyte, wherein,
the air electrode comprises the catalyst for an air secondary battery according to claim 8 .

13. The air secondary battery according to claim 12 , wherein the negative electrode comprises a hydrogen storage alloy.

Assignees

• Fdk Corp

Inventors

• Unoki Shohei
• Kajiwara Takeshi
• Endo Takahiro
• Yasuoka Shigekazu
• Watanabe Yoshikatsu

Classifications

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M2004/027

  Negative electrodes · CPC title

• H01M4/9033

  Complex oxides, optionally doped, of the type M1MeO3, M1 being an alkaline earth metal or a rare earth, Me being a metal, e.g. perovskites · CPC title

• B01J37/088

  Decomposition of a metal salt · CPC title

• B01J37/0036

  Grinding · CPC title