Abstract: A battery includes: an electrode group including an air electrode and a negative electrode that are stacked with a separator interposed therebetween; and a container housing the electrode group together with an alkaline electrolyte liquid. The air electrode includes a catalyst for an air electrode. This catalyst for an air electrode is a catalyst for an air electrode including an oxide containing at least bismuth (Bi), ruthenium (Ru), sodium (Na), and oxygen, and Na/(Ru+Bi+Na) representing an atomic ratio of the sodium to a sum of the bismuth, the ruthenium, and the sodium is 0.126 or more and 0.145 or less.

Abstract: A battery includes: an electrode group including an air electrode and a negative electrode that are stacked with a separator interposed therebetween; and a container housing the electrode group together with an alkaline electrolyte liquid. The air electrode includes a catalyst for an air secondary battery, and this catalyst for an air secondary battery includes a pyrochlore bismuth-ruthenium composite oxide having a full width at half maximum of a diffraction peak corresponding to a (222) face obtained by a powder X-ray diffraction method using CuK? rays as X-rays, of 0.350 deg or larger and 0.713 deg or smaller.

Abstract: A battery includes: an electrode group including an air electrode and a negative electrode that are stacked with a separator interposed therebetween; and a container housing the electrode group together with an alkaline electrolyte liquid. The air electrode includes a catalyst for an air electrode. This catalyst for an air electrode is a catalyst for an air electrode including an oxide containing at least bismuth (Bi), ruthenium (Ru), sodium (Na), and oxygen, and Na/(Ru+Bi+Na) representing an atomic ratio of the sodium to a sum of the bismuth, the ruthenium, and the sodium is 0.126 or more and 0.145 or less.

Abstract: An air electrode catalyst for an air secondary battery includes a pyrochlore-type composite oxide having two or more crystal structures having a different amount of oxygen. A battery, according to some embodiments, includes an electrode group including an air electrode and a negative electrode stacked with a separator therebetween, and a container accommodating the electrode group along with an alkali electrolyte solution, wherein the air electrode includes the air electrode catalyst. The air electrode catalyst may have a pyrochlore-type composite oxide having a crystal structure represented by Bi2Ru2O6.92 and a crystal structure represented by Bi2Ru2O7.33.

Abstract: A battery includes an electrode group including an air electrode and a negative electrode stacked with a separator therebetween, and a battery case accommodating the electrode group along with an alkali electrolyte solution, wherein the air electrode includes an air electrode mixture containing a pyrochlore-type composite oxide and a manganese oxide, and the pyrochlore-type composite oxide is a bismuth-ruthenium oxide.

Abstract: A battery includes an electrode group including an air electrode and a negative electrode stacked with a separator therebetween, and an accommodating bag accommodating the electrode group along with an alkali electrolyte solution. The air electrode includes a catalyst for an air secondary battery. This catalyst for an air secondary battery is produced by a method for producing a catalyst for an air secondary battery, the method including a precursor preparation step of preparing a bismuth-ruthenium oxide precursor, a calcination step of calcining the bismuth-ruthenium oxide precursor obtained in this precursor preparation step to form a bismuth-ruthenium oxide, and a nitric acid treatment step of immersing the bismuth-ruthenium oxide obtained by this calcination step in a nitric acid aqueous solution.

Abstract: A battery includes an electrode group including an air electrode and a negative electrode stacked with a separator therebetween, and an accommodating bag accommodating the electrode group along with an alkali electrolyte solution. The air electrode includes a catalyst for an air secondary battery. This catalyst for an air secondary battery is produced by a method for producing a catalyst for an air secondary battery, the method including a precursor preparation step of preparing a bismuth-ruthenium oxide precursor, a calcination step of calcining the bismuth-ruthenium oxide precursor obtained in this precursor preparation step to form a bismuth-ruthenium oxide, and a nitric acid treatment step of immersing the bismuth-ruthenium oxide obtained by this calcination step in a nitric acid aqueous solution.

Abstract: An air electrode catalyst for an air secondary battery includes a pyrochlore-type composite oxide having two or more crystal structures having a different amount of oxygen. A battery, according to some embodiments, includes an electrode group including an air electrode and a negative electrode stacked with a separator therebetween, and a container accommodating the electrode group along with an alkali electrolyte solution, wherein the air electrode includes the air electrode catalyst. The air electrode catalyst may have a pyrochlore-type composite oxide having a crystal structure represented by Bi2Ru2O6.92 and a crystal structure represented by Bi2Ru2O7.33.

Abstract: A battery includes an electrode group including an air electrode and a negative electrode stacked with a separator therebetween, and a battery case accommodating the electrode group along with an alkali electrolyte solution, wherein the air electrode includes an air electrode mixture containing a pyrochlore-type composite oxide and a manganese oxide, and the pyrochlore-type composite oxide is a bismuth-ruthenium oxide.