Zinc-air secondary battery

Patent metadata

Field	Value
Publication number	US-2017271731-A1
Application number	US-201715610726-A
Country	US
Kind code	A1
Filing date	Jun 1, 2017
Priority date	Dec 2, 2014
Publication date	Sep 21, 2017
Grant date	—

Abstract

Provided is a zinc-air secondary battery including an air electrode; a negative electrode containing zinc, a zinc alloy, and/or a zinc compound; an aqueous electrolytic solution in which the negative electrode is immersed; a container having an opening and accommodating the negative electrode and the electrolytic solution; and a separator disposed to cover the opening and having hydroxide ion conductivity, water impermeability, and gas impermeability, the separator being in contact with the electrolytic solution and defining a hermetic space with the container such that the air electrode is separated from the electrolytic solution by the separator through which hydroxide ions pass. The hermetic space has an extra 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. The present invention provides a highly reliable zinc-air secondary battery.

First claim

What is claimed is:

1 . A zinc-air secondary battery comprising:
an air electrode serving as a positive electrode; a negative electrode comprising zinc, a zinc alloy, and/or a zinc compound; an aqueous electrolytic solution, the negative electrode being immersed in the aqueous electrolytic solution; a container having an opening and accommodating the negative electrode and the electrolytic solution; and a separator disposed to cover the opening and having hydroxide ion conductivity, water impermeability, and gas impermeability, the separator being in contact with the electrolytic solution and defining a hermetic space with the container such that the air electrode is separated from the electrolytic solution by the separator through which hydroxide ions pass, wherein the hermetic space has an extra 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.

2 . The zinc-air secondary battery according to claim 1 , wherein the extra 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 space is preliminarily filled with an amount of the aqueous electrolytic solution that will decrease during the charge of the battery.

3 . The zinc-air secondary battery according to claim 1 , wherein the extra 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 space is not preliminarily filled with the aqueous electrolytic solution.

4 . The zinc-air secondary battery according to claim 1 , wherein the extra space is not filled with the negative electrode.

5 . The zinc-air secondary battery according to claim 1 , wherein the separator is vertically disposed, and the hermetic space has the extra space in its upper portion.

6 . The zinc-air secondary battery according to claim 1 , further comprising a third electrode in the container, wherein the third electrode is disposed to be in contact with the electrolytic solution, but not in contact with the negative electrode, and the third electrode is connected to the air electrode via an external circuit.

7 . The zinc-air secondary battery according to claim 6 , wherein the third electrode is disposed in the extra space.

8 . The zinc-air secondary battery according to claim 1 , wherein the separator comprises an inorganic solid electrolyte.

9 . The zinc-air secondary battery according to claim 8 , wherein the inorganic solid electrolyte has a relative density of 90% or more.

10 . The zinc-air secondary battery according to claim 8 , wherein the inorganic solid electrolyte comprises a layered double hydroxide having a basic composition represented by the formula:
M 2+ 1-x M 3+ x (OH) 2 A n- x/n .m H 2 O where M 2+ represents a divalent cation, M 3+ represents a 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 0 or more.

11 . The zinc-air secondary battery according to claim 10 , wherein M 2+ comprises Mg 2+ , M 3+ comprises Al 3+ , and A n comprises OH − and/or CO 3 2− in the formula.

12 . The zinc-air secondary battery according to claim 8 , wherein the inorganic solid electrolyte is in a plate, membrane, or layer form.

13 . The zinc-air secondary battery according to claim 8 , further comprising a porous substrate on either or both of the surfaces of the separator.

14 . The zinc-air secondary battery according to claim 13 , wherein the inorganic solid electrolyte is in a membrane or layer form, and is disposed on or in the porous substrate.

15 . The zinc-air secondary battery according to claim 13 , wherein the inorganic solid electrolyte comprises a layered double hydroxide composed of an aggregation of platy particles, and the platy particles are oriented such that the tabular faces of the platy particles are substantially perpendicular to or oblique to a surface of the porous substrate.

16 . The zinc-air secondary battery according to claim 8 , wherein the inorganic solid electrolyte is densified through hydrothermal treatment.

17 . The zinc-air secondary battery according to claim 1 , further comprising a positive-electrode collector having gas permeability, wherein the positive-electrode collector is disposed on the surface of the air electrode remote from the separator.

18 . The zinc-air secondary battery according to claim 1 , further comprising a negative-electrode collector in contact with the negative electrode.

19 . The zinc-air secondary battery according to claim 1 , wherein the negative-electrode collector extends through the container to the exterior.

20 . The zinc-air secondary battery according to claim 1 , wherein the aqueous electrolytic solution is an aqueous alkali metal hydroxide solution.

Assignees

• Ngk Insulators Ltd

Inventors

• Hayashi Hiroshi
• Yamada Naohito
• Kitoh Kenshin

Classifications

• H01M10/0562

  Solid materials · CPC title

• H01M4/86

  Inert electrodes with catalytic activity, e.g. for fuel cells · CPC title

• H01M12/08 Primary

  composed of a half-cell of a fuel-cell type and a half-cell of the secondary-cell type · CPC title

• H01M8/08

  Fuel cells with aqueous electrolytes · CPC title

• H01M10/26

  Selection of materials as electrolytes · CPC title