Nickel-zinc Battery

Patent metadata

Field	Value
Publication number	US-10263292-B2
Application number	US-201615358556-A
Country	US
Kind code	B2
Filing date	Nov 22, 2016
Priority date	Jul 9, 2014
Publication date	Apr 16, 2019
Grant date	Apr 16, 2019

Abstract

Provided is a highly reliable nickel-zinc battery including a separator exhibiting hydroxide ion conductivity and water impermeability. The nickel-zinc battery includes a positive electrode containing nickel hydroxide and/or nickel oxyhydroxide; a positive-electrode electrolytic solution in which the positive electrode is immersed, the electrolytic solution containing an alkali metal hydroxide; a negative electrode containing zinc and/or zinc oxide; a negative-electrode electrolytic solution in which the negative electrode is immersed, the electrolytic solution containing an alkali metal hydroxide; a hermetic container accommodating the positive electrode, the positive-electrode electrolytic solution, the negative electrode, and the negative-electrode electrolytic solution; and the separator exhibiting hydroxide ion conductivity and water impermeability and disposed in the hermetic container so as to separate a positive-electrode chamber from a negative-electrode chamber. The alkali metal hydroxide concentration of the positive-electrode electrolytic solution differs from that of the negative-electrode electrolytic solution.

First claim

What is claimed is:

1. A nickel-zinc battery comprising:
a positive electrode comprising nickel hydroxide and/or nickel oxyhydroxide;
a positive-electrode electrolytic solution comprising an alkali metal hydroxide, the positive electrode being immersed in the positive-electrode electrolytic solution;
a negative electrode comprising zinc and/or zinc oxide;
a negative-electrode electrolytic solution comprising an alkali metal hydroxide, the negative electrode being immersed in the negative-electrode electrolytic solution;
a hermetic container accommodating the positive electrode, the positive-electrode electrolytic solution, the negative electrode, and the negative-electrode electrolytic solution; and
an inorganic solid electrolyte separator comprising a layered double hydroxide exhibiting hydroxide ion conductivity and water impermeability, the separator being disposed in the hermetic container so as to separate a positive-electrode chamber accommodating the positive electrode and the positive-electrode electrolytic solution from a negative-electrode chamber accommodating the negative electrode and the negative-electrode electrolytic solution,
wherein the alkali metal hydroxide concentration of the positive-electrode electrolytic solution differs from the alkali metal hydroxide concentration of the negative-electrode electrolytic solution.

2. The nickel-zinc battery according to claim 1 , wherein the alkali metal hydroxide concentration of the positive-electrode electrolytic solution is 1 to 9 M.

3. The nickel-zinc battery according to claim 1 , wherein the alkali metal hydroxide concentration of the negative-electrode electrolytic solution is 3 to 18 M.

4. The nickel-zinc battery according to claim 1 , wherein the alkali metal hydroxide concentration of the positive-electrode electrolytic solution is lower than the alkali metal hydroxide concentration of the negative-electrode electrolytic solution in a full charge state.

5. The nickel-zinc battery according to claim 1 , wherein the alkali metal hydroxide concentration of the positive-electrode electrolytic solution is higher than the alkali metal hydroxide concentration of the negative-electrode electrolytic solution in a discharge end state.

6. The nickel-zinc battery according to claim 1 , wherein the nickel-zinc battery is prepared in a discharge end state, and the alkali metal hydroxide concentration of the positive-electrode electrolytic solution is higher than the alkali metal hydroxide concentration of the negative-electrode electrolytic solution during preparation of the battery.

7. The nickel-zinc battery according to claim 1 , wherein the nickel-zinc battery is prepared in a full charge state, and the alkali metal hydroxide concentration of the positive-electrode electrolytic solution is lower than the alkali metal hydroxide concentration of the negative-electrode electrolytic solution during preparation of the battery.

8. The nickel-zinc battery according to claim 1 , wherein the average alkali metal hydroxide concentration of the negative-electrode electrolytic solution is higher than the average alkali metal hydroxide concentration of the positive-electrode electrolytic solution from a full charge state to a discharge end state or from a discharge end state to a full charge state.

9. The nickel-zinc battery according to claim 1 , wherein the alkali metal hydroxide is potassium hydroxide.

10. The nickel-zinc battery according to claim 1 , wherein the positive-electrode electrolytic solution is an aqueous potassium hydroxide solution, and the negative-electrode electrolytic solution is an aqueous potassium hydroxide solution containing Zn(OH) 4 2− .

11. The nickel-zinc battery according to claim 1 , wherein the positive-electrode chamber has an extra positive-electrode space having a volume that meets a variation in amount of water in association with reaction at the positive electrode during charge and discharge of the battery, and the negative-electrode chamber has an extra negative-electrode space having a volume that meets a variation in amount of water in association with reaction at the negative electrode during charge and discharge of the battery.

12. The nickel-zinc battery according to claim 11 , wherein the extra positive-electrode space has a volume greater than the amount of water that will increase in association with reaction at the positive electrode during the charge of the battery; the extra positive-electrode space is not preliminarily filled with the positive-electrode electrolytic solution; the extra negative-electrode space has a volume greater than the amount of water that will decrease in association with reaction at the negative electrode during the charge of the battery; and the extra negative-electrode space is preliminarily filled with an amount of the negative-electrode electrolytic solution that will decrease during the charge of the battery.

13. The nickel-zinc battery according to claim 11 , wherein the extra positive-electrode space has a volume greater than the amount of water that will decrease in association with reaction at the positive electrode during the discharge of the battery; the extra positive-electrode space is preliminarily filled with an amount of the positive-electrode electrolytic solution that will decrease during the discharge of the battery; the extra negative-electrode space has a volume greater than the amount of water that will increase in association with reaction at the negative electrode during the discharge of the battery; and the extra negative-electrode space is not preliminarily filled with the negative-electrode electrolytic solution.

14. The nickel-zinc battery according to claim 1 , wherein the extra positive-electrode space is not filled with the positive electrode and the extra negative-electrode space is not filled with the negative electrode.

15. The nickel-zinc battery according to claim 11 , further comprising a gas flow channel that connects the extra positive-electrode space to the extra negative-electrode space such that the spaces are in gas communication with each other.

16. The nickel-zinc battery according to claim 11 , wherein the separator is vertically disposed, the extra positive-electrode space is provided in an upper portion of the positive-electrode chamber, and the extra negative-electrode space is provided in an upper portion of the negative-electrode chamber.

17. The nickel-zinc battery according to claim 1 , wherein the inorganic solid electrolyte has a relative density of 90% or more.

18. The nickel-zinc battery according to claim 1 , wherein the layered double hydroxide has a basic composition represented by the general formula:
M 2+ 1−x M 3+ x (OH) 2 A n− x/n .mH 2 O

where M 2+ represents at least one divalent cation, M 3+ represents at least one trivalent cation, A n− represents an n-valent anion, n is an integer of 1 or more, x is 0.1 to 0.4, and m is any real number.

19. The nickel-zinc battery according to claim 1 , wherein the inorganic solid electrolyte is in a plate, membrane, or layer form.

20. The nickel-zinc battery according to claim 1 , further comprising a porous substrate on either or both of the surfaces of the separator.

21. The nickel-zinc battery according to claim 20 , wherein the inorganic solid electrolyte is in a membrane or layer form, and is disposed on or in the porous substrate.

22. The nickel-zinc battery according to claim 1 , wherein the inorganic solid electrolyte is densified throu

Assignees

• Ngk Insulators Ltd

Inventors

• Hayashi Hiroshi
• Yamada Naohito
• Kitoh Kenshin

Classifications

• H01M50/443

  Particulate material · CPC title

• H01M50/103

  prismatic or rectangular (H01M50/109, H01M50/11 take precedence) · CPC title

• H01M10/30

  Nickel accumulators (H01M10/34 takes precedence) · CPC title

• H01M2/0202

  Electricity · mapped topic

• H01M4/42

  Alloys based on zinc · CPC title