Abstract: A protein template is added to a solution in which metal ions of iron and copper are dissolved to introduce the metal ions into the protein template; the protein template is separated from metal ions that have not been incorporated in the protein template; the metal ions that have been incorporated in the protein template are reduced to obtain a protein containing alloy nanoparticles of iron and copper; a sol or gel in which a co-continuous body is dispersed is frozen; the frozen sol or gel is dried in a vacuum to obtain a porous body; the porous body is allowed to support the alloy nanoparticle containing protein; and the protein is removed.

Abstract: A primary battery includes a positive electrode containing isatin, a negative electrode containing magnesium or aluminum, and an electrolyte disposed between the positive electrode and the negative electrode.

Abstract: The present invention provides an air battery using oxygen in air as a cathode active material, the air battery comprising: a cylindrical anode made of a metal; a cathode constituted by a co-continuous body having a three dimensional network structure formed by an integrated plurality of nanostructures having branches; and a separator that is arranged between the cathode and the anode and absorbs an electrolytic solution, wherein: the cathode is arranged inside the anode via the separator; and the anode has an open hole that reaches the separator and constitutes a housing of the air battery.