Provided is an air electrode or water electrolysis anode showing a higher catalytic activity than carbon black and not having a risk of oxidative degradation, in particular, an air electrode or water electrolysis anode for a metal-air battery or a water electrolysis apparatus. The air electrode or water electrolysis anode includes an electron-conductive material represented by LaNi.sub.1−x−yCu.sub.xFe.sub.yO.sub.3−δ (where x>0, y>0, x+y<1, and 0≦δ≦0.4).

Provided is an air electrode or water electrolysis anode showing a higher catalytic activity than carbon black and not having a risk of oxidative degradation, in particular, an air electrode or water electrolysis anode for a metal-air battery or a water electrolysis apparatus. The air electrode or water electrolysis anode includes an electron-conductive material represented by LaNi.sub.1−x−yCu.sub.xFe.sub.yO.sub.3−δ (where x>0, y>0, x+y<1, and 0≦δ≦0.4).

In a case where an alkali aqueous solution is used as an electrolyte, provided are an oxygen catalyst excellent in catalytic activity and composition stability, an electrode having high activity and stability using this oxygen catalyst, and an electrochemical measurement method that can evaluate the catalytic activity of the oxygen catalyst alone. The oxygen catalyst is an oxide having peaks at positions of 2θ=30.07°±1.00°, 34.88°±1.00°, 50.20°±1.00°, and 59.65°±1.00° in an X-ray diffraction measurement using a CuKα ray, and having constituent elements of bismuth, ruthenium, sodium, and oxygen. An atom ratio O/Bi of oxygen to bismuth and an atom ratio O/Ru of oxygen to ruthenium are both more than 3.5.

Electrochemical devices including electrochemically-driven carbon dioxide separators are disclosed, the devices including electrodes comprised of an anion exchange polymer and a charge storage compound such as nickel hydroxide and a membrane comprising an anion exchange poiymer, the membrane having a channel for inflow of a carbon dioxide-containing gas within the membrane.

Electrochemical devices including electrochemically-driven carbon dioxide separators are disclosed, the devices including electrodes comprised of an anion exchange polymer and a charge storage compound such as nickel hydroxide and a membrane comprising an anion exchange poiymer, the membrane having a channel for inflow of a carbon dioxide-containing gas within the membrane.

A metal air battery includes an air electrode containing a conductive material and a catalyst, a negative electrode containing a metal, and an electrolyte having ionic conductivity. The conductive material contains a co-continuous body of a three-dimensional network structure in which nanostructure bodies are branched, and the catalyst contains oxide having a cage-shaped crystal structure.

A metal air battery includes an air electrode containing a conductive material and a catalyst, a negative electrode containing a metal, and an electrolyte having ionic conductivity. The conductive material contains a co-continuous body of a three-dimensional network structure in which nanostructure bodies are branched, and the catalyst contains oxide having a cage-shaped crystal structure.

A gas permeable or breathable electrode and method of manufacture thereof. In one example there is an electrolytic cell having an electrode comprising a porous material, wherein gas produced at the electrode diffuses out of the cell via the porous material. In operation the gas is produced at the at least one electrode without substantial bubble formation. In another example there is an electrode having a porous conducting material with a hydrophobic layer or coating applied to a side of the porous conducting material. A catalyst may be applied to another side. The gas permeable or breathable electrode can be used in an electrolytic cell, electrochemical cell, battery and/or fuel cell. Gas produced at the electrode diffuses out of a cell via at least part of the electrode, separating the gas from the reaction at the electrode.

A gas permeable or breathable electrode and method of manufacture thereof. In one example there is an electrolytic cell having an electrode comprising a porous material, wherein gas produced at the electrode diffuses out of the cell via the porous material. In operation the gas is produced at the at least one electrode without substantial bubble formation. In another example there is an electrode having a porous conducting material with a hydrophobic layer or coating applied to a side of the porous conducting material. A catalyst may be applied to another side. The gas permeable or breathable electrode can be used in an electrolytic cell, electrochemical cell, battery and/or fuel cell. Gas produced at the electrode diffuses out of a cell via at least part of the electrode, separating the gas from the reaction at the electrode.

An alkaline electrochemical cell, preferably a zinc/air cell which includes a container; a negative electrode, a positive electrode, wherein said negative electrode and said positive electrode are disposed within the container, and an alkaline electrolyte, wherein the negative electrode comprises zinc, a branched chain fluorosurfactant, barium sulfate (and, more specifically, amino- and/or epoxy-funcationalized barium sulfate) and nano sized zinc oxide. The negative electrode composition supports high zinc to electrolyte weight ratios.