Abstract: A layered double hydroxide contains four elements of Ni, Fe, V, and Co, and further contains Mn as a fifth element.

Abstract: A layered double hydroxide is represented by the following formula (I): Ni2+1?(x+y+z)Fe3+xV3+yCo3+z(OH)2An?(x+y+z)/n·mH2O . . . (I). In one embodiment, in the formula (I), (x+y+z) is from 0.2 to 0.5, “x” represents more than 0 and 0.3 or less, “y” represents from 0.04 to 0.49, and “z” represents more than 0 and 0.2 or less.

Abstract: Provided is an air electrode/separator assembly including: a hydroxide ion conductive dense separator; an interface layer containing a hydroxide ion conductive material and an electron conductive material and covering one side of the hydroxide ion conductive dense separator; and an air electrode layer provided on the interface layer and including an outermost catalyst layer composed of a porous current collector and a layered double hydroxide (LDH) covering a surface thereof. The outermost catalyst layer has a porosity of 60% or more.

Abstract: Provided is an air electrode/separator assembly including: a hydroxide ion conductive separator, an interface layer containing a hydroxide ion conductive material and an electron conductive material and covering one side of the hydroxide ion conductive separator; an air electrode layer provided on the interface layer and including a catalyst layer composed of a porous current collector and a layered double hydroxide (LDH) covering a surface thereof, and a water repellent porous layer covering a surface of the air electrode opposite to the hydroxide ion conductive separator.

Abstract: Provided is an air electrode/separator assembly including a hydroxide ion conductive separator including an inner space, a pair of catalyst layers covering both surfaces of the hydroxide ion conductive separator and containing a catalyst for an air electrode, a hydroxide ion conductive material, and an electron conductive material, a pair of gas diffusion electrodes provided on the pair of catalyst layers on a side opposite to the hydroxide ion conductive separator, and a water absorption/desorption layer provided so as to contact both of the pair of catalyst layers, having water absorbability and desorbability. One of the pair of catalyst layers is a catalyst layer for discharge and the other of the pair of catalyst layers is a catalyst layer for charge; and the hydroxide ion conductive separator, the catalyst layer, and the gas diffusion electrode are arranged vertically, and the water absorption/desorption layer is positioned below the catalyst layer.

Abstract: Provided is an air electrode/separator assembly including a hydroxide ion conductive separator, a catalyst layer including a catalyst for an air electrode, a hydroxide ion conductive material, an electron conductive material, a binder, and a humidity conditioning material and covering one side of the hydroxide ion conductive separator, and a gas diffusion electrode provided on the catalyst layer on a side opposite to the hydroxide ion conductive separator.

Abstract: A layered double hydroxide is represented by the following formula (I): Ni2+1?(x+y+z)Fe3+xV3+yCo3+z(OH)2An?(x+y+z)/n·mH2O . . . (I). In one embodiment, in the formula (I), (x+y+z) is from 0.2 to 0.5, “x” represents more than 0 and 0.3 or less, “y” represents from 0.04 to 0.49, and “z” represents more than 0 and 0.2 or less.

Abstract: Provided is an air electrode/separator assembly including a hydroxide ion conductive dense separator and an air electrode layer provided on one side of the hydroxide ion conductive dense separator. The air electrode layer includes: an internal catalyst layer provided closer to the hydroxide ion conductive dense separator and filled with a mixture containing a hydroxide ion conductive material, an electron conductive material, an organic polymer, and an air electrode catalyst (provided that the hydroxide ion conductive material may be the same material as the air electrode catalyst, and provided that the electron conductive material may be the same material as the air electrode catalyst); and an outermost catalyst layer provided away from the hydroxide ion conductive dense separator having a porosity of 60% or more, composed of a porous current collector and a layered double hydroxide (LDH) covering a surface thereof.

Abstract: Provided is an air electrode/separator assembly including: a hydroxide ion conductive dense separator; an interface layer containing a hydroxide ion conductive material and an electron conductive material and covering one side of the hydroxide ion conductive dense separator; and an air electrode layer provided on the interface layer and including an outermost catalyst layer composed of a porous current collector and a layered double hydroxide (LDH) covering a surface thereof. The outermost catalyst layer has a porosity of 60% or more.