Battery using layered double hydroxide-like compound
Provided is a battery including a positive electrode; a negative electrode; an electrolytic solution being an aqueous alkali metal hydroxide solution; and a layered double hydroxide (LDH)-like compound provided so as to be in contact with the electrolytic solution. A metal compound containing at least one metal element constituting the LDH-like compound is dissolved in the electrolytic solution such that erosion of the LDH-like compound by the electrolytic solution is suppressed.
1 . A battery with a layered double hydroxide (LDH)-like compound, the battery comprising:
a positive electrode;
a negative electrode;
an electrolytic solution being an aqueous alkali metal hydroxide solution; and
an LDH-like compound provided so as to be in contact with the electrolytic solution,
wherein a metal compound containing at least one metal element constituting the LDH-like compound is dissolved in the electrolytic solution such that erosion of the LDH-like compound by the electrolytic solution is suppressed.
2 . The battery according to claim 1 , wherein the LDH-like compound is:
(a) a hydroxide and/or an oxide with a layered crystal structure, containing: Mg and Ti; and optionally one or more selected from the group consisting of Y and Al, or
(b) a hydroxide and/or an oxide with a layered crystal structure, comprising (i) Ti, Y, and optionally Al and/or Mg, and (ii) at least one additive element M selected from the group consisting of In, Bi, Ca, Sr, and Ba, or
(c) a hydroxide and/or an oxide with a layered crystal structure, comprising Mg, Ti, Y, and optionally Al and/or In, wherein in (c) the LDH-like compound is present in a form of a mixture with In (OH) 3 .
3 . The battery according to claim 1 , wherein the aqueous alkali metal hydroxide solution is an aqueous potassium hydroxide solution.
4 . The battery according to claim 1 , wherein the metal element is dissolved in the electrolytic solution in the form of a metal ion, a hydroxide, and/or a hydroxy complex.
5 . The battery according to claim 1 , wherein the metal compound is preliminarily dissolved in the electrolytic solution.
6 . The battery according to claim 1 , wherein the LDH-like compound comprises Al, and wherein the metal compound comprises A1.
7 . The battery according to claim 6 , wherein the electrolytic solution has an Al concentration of 0.1 mol/L or more.
8 . The battery according to claim 6 , wherein the electrolytic solution has an Al concentration of 2.0 mol/L or more.
9 . The battery according to claim 1 , wherein the metal compound is aluminum hydroxide and/or γ-alumina.
10 . The battery according to claim 1 , wherein the battery comprises the LDH-like compound as a separator exhibiting hydroxide ion conductivity, and the separator separates the positive electrode from the negative electrode.
11 . The battery according to claim 10 , wherein the separator further comprises an additional material other than the LDH-like compound.
12 . The battery according to claim 11 , wherein the additional material is a polymer.
13 . The battery according to claim 11 , wherein the separator is densified to exhibit water impermeability and gas impermeability.
14 . The battery according to claim 10 , wherein the separator further comprises a porous substrate, and the LDH-like compound plugs pores in the porous substrate.
15 . The battery according to claim 14 , wherein the porous substrate is composed of a polymer material.
16 . The battery according to claim 1 , wherein the negative electrode is coated with the LDH-like compound.