Electrode for metal-air battery

An electrode for a metal-air battery, wherein:

• a catalyst layer of an air electrode of a metal-air battery contains a catalyst element and a carbon material,
• the carbon material comprises two materials of a hydrophilic carbon material A having supported thereon the catalyst element and a hydrophobic carbon material B not supporting the catalyst element,
• the catalyst layer comprises a hydrophilic agglomerate X containing more than 50 mass % in total of the catalyst element, the carbon material A and the carbon material B, and a hydrophobic agglomerate Y containing more than 50 mass % of the carbon material B,
• the agglomerate X is a continuum and the agglomerate Y is dispersed in the agglomerate x,
• the carbon material A satisfies the following characteristic feature (i) or (ii), and
• in the carbon material B, a water vapor adsorption amount is less than 0.1 cm3/g in an environment of 25° C. and a relative pressure of 0.1 and a ratio (X/SBET) of the DBP absorption (X) (cm3/100 g) to a specific surface area (SBET) by BET evaluation is 0.5 or more, and wherein
• an interface between an aqueous electrolyte solution and an air is formed in the catalyst layer;
• (i) in the carbon material A, the water vapor adsorption amount is 0.1 cm3/g or more in an environment of 25° C. and a relative pressure of 0.1, a ratio Smicro/Stotal of a micropore surface area Smicro as determined by t-plot analysis of a nitrogen adsorption isotherm to a total surface area Stotal is 0.90 or more, an average particle diameter d50 is less than 1.5 μm, and a ratio (d90−d10)/d50 of the difference between d90 and d10 (d90−d10) to d50 is less than 1.0;
• or
• (ii) in the carbon material A, the water vapor adsorption amount is 0.1 cm3/g or more in an environment of 25° C. and a relative pressure of 0.1 and the ratio Smicro/Stotal of the micropore surface area Smicro as determined by t-plot analysis of a nitrogen adsorption isotherm to the total surface area Stotal is 0.90 or less.