Abstract: A metal-air battery (1) includes a tubular positive electrode (2) centered on a predetermined central axis (J1), a negative electrode (3) opposing an inner side surface of the positive electrode, and an electrolyte layer (4) disposed between the negative electrode and the positive electrode. The positive electrode includes a positive electrode conductive layer (21), a positive electrode catalyst layer (22), and a positive electrode current collector (24). The positive electrode catalyst layer is formed on the outer side surface of the tubular positive electrode conductive layer centered on the central axis and has lower electrical conductivity than the positive electrode conductive layer. The positive electrode current collector is formed on an area of the outer side surface of the positive electrode conductive layer where the positive electrode catalyst layer does not exist, to be in direct contact with the outer side surface.

Abstract: A positive electrode of a metal-air secondary battery includes a conductive layer having electrical conductivity, and a catalyst layer laminated on the conductive layer. Particles of different types of perovskite oxides, namely a first perovskite-type oxide and a second perovskite-type oxide, are dispersed in the catalyst layer. The first perovskite-type oxide has an average particle diameter greater than or equal to 2 micrometers and less than or equal to 9 micrometers, and the second perovskite-type oxide has an average particle diameter greater than or equal to 0.10 micrometers and less than or equal to 1.0 micrometers. This composition improves battery performance while maintaining a certain level of strength of the catalyst layer.

Abstract: In a metal-air battery (1), an interconnector (24) formed of ceramic having alkali resistance is provided on the surface of a porous positive electrode layer (2) on the side opposite to the surface that is in contact with an electrolyte layer (4). A liquid repellent layer (29) having liquid repellency to an electrolyte solution is further provided on the surface of the positive electrode layer (2) on which the interconnector (24) is formed, and covers this surface along with the interconnector (24). The metal-air battery (1) using an alkaline electrolyte solution can thus easily prevent leakage of the electrolyte solution by the interconnector (24) and the liquid repellent layer (29) while suppressing degradation of the interconnector (24).

Abstract: A metal-air battery (1) includes a tubular positive electrode (2) centered on a predetermined central axis (J1), a negative electrode (3) opposing an inner side surface of the positive electrode, and an electrolyte layer (4) disposed between the negative electrode and the positive electrode. The positive electrode includes a positive electrode conductive layer (21), a positive electrode catalyst layer (22), and a positive electrode current collector (24). The positive electrode catalyst layer is formed on the outer side surface of the tubular positive electrode conductive layer centered on the central axis and has lower electrical conductivity than the positive electrode conductive layer. The positive electrode current collector is formed on an area of the outer side surface of the positive electrode conductive layer where the positive electrode catalyst layer does not exist, to be in direct contact with the outer side surface.

Abstract: A metal-air battery has a positive electrode including a positive electrode conductive layer, a first catalyst layer, and a second catalyst layer. The positive electrode conductive layer is a porous layer made of conductive ceramic and has pores filled with an electrolyte solution. The first catalyst layer is a porous layer formed on a surface of the positive electrode conductive layer on the side opposite to the negative electrode, is made of conductive ceramic having a smaller average particle diameter than that of the positive electrode conductive layer, and has pores filled with the electrolyte solution. This improves charge performance. The second catalyst layer is a porous layer formed on a surface of the first catalyst layer on the side opposite to the negative electrode and is made of conductive ceramic having a larger average particle diameter than that of the first catalyst layer. This improves discharge performance.

Abstract: A metal-air battery (1) includes a tubular positive electrode (2), a negative electrode (3) opposing an inner side surface of the positive electrode (2), and an electrolyte layer (4) disposed between the negative electrode (3) and the positive electrode (2). The positive electrode (2) includes a porous positive electrode main body (21) that is made of conductive ceramic and serves as a tubular supporter, and a separator (41) that is a porous film made of ceramic having insulating properties is formed on the inner side surface of the positive electrode main body (21). Using the positive electrode main body (21) as a supporter makes it possible to easily increase the thickness of the positive electrode (2) and to thereby reduce the electrical resistance of the positive electrode (2) and improve the battery performance of the metal-air battery (1).

Abstract: A metal-air battery (1) includes a negative electrode (3), a positive electrode (2), and an electrolyte layer (4) disposed between the negative electrode (3) and the positive electrode (2). The negative electrode (3) includes a base member (31) which has a coiled shape and is formed of a conductive material and a deposited metal layer (32) in powder or particle state, which is formed on a surface of the base member (31) by electrolytic deposition. The electrolyte layer (4) contains an alkaline aqueous solution which contains the same metal as the deposited metal layer (32), and the positive electrode (2) has a tubular shape which is concentric with the negative electrode (3) having the coiled shape and surrounds the negative electrode (3). In this metal-air battery (1), it is possible to suppress occurrence of dendrites in the negative electrode (3).

Abstract: In a metal-air battery (1), an interconnector (24) formed of ceramic having alkali resistance is provided on the surface of a porous positive electrode layer (2) on the side opposite to the surface that is in contact with an electrolyte layer (4). A liquid repellent layer (29) having liquid repellency to an electrolyte solution is further provided on the surface of the positive electrode layer (2) on which the interconnector (24) is formed, and covers this surface along with the interconnector (24). The metal-air battery (1) using an alkaline electrolyte solution can thus easily prevent leakage of the electrolyte solution by the interconnector (24) and the liquid repellent layer (29) while suppressing degradation of the interconnector (24).

Abstract: A metal-air battery (1) includes a negative electrode (3), a positive electrode (2), and an electrolyte layer (4) disposed between the negative electrode (3) and the positive electrode (2). The negative electrode (3) includes a base member (31) which has a coiled shape and is formed of a conductive material and a deposited metal layer (32) in powder or particle state, which is formed on a surface of the base member (31) by electrolytic deposition. The electrolyte layer (4) contains an alkaline aqueous solution which contains the same metal as the deposited metal layer (32), and the positive electrode (2) has a tubular shape which is concentric with the negative electrode (3) having the coiled shape and surrounds the negative electrode (3). In this metal-air battery (1), it is possible to suppress occurrence of dendrites in the negative electrode (3).

Abstract: A metal-air battery (1) includes a porous negative electrode (3) having a tubular shape and containing a metal, a porous positive electrode (2) having a tubular shape that surrounds the outer surface of the negative electrode (3), and an electrolyte layer (4) disposed between the negative electrode (3) and the positive electrode (2) and containing electrolyte solution. A filled part (31) enclosed by the inner surface of the negative electrode (3) is filled with electrolyte solution, and the electrolyte layer (4) is in communication with the filled part (31) via the porous negative electrode (3). The metal-air battery (1) further includes a supply-collection part (6) for collecting electrolyte solution in the filled part (31) and supplying electrolyte solution to the filled part (31). This facilitates replacement or the like of the electrolyte solution contained in the electrolyte layer (4).

Abstract: In a metal-air battery, a negative electrode, an electrolyte layer, and a positive electrode are concentrically disposed in the stated order, radially outward from the central axis, and the outer circumferential surface of the positive electrode is enclosed by a liquid-repellent layer (29). The liquid-repellent layer (29) includes a relatively high-strength inorganic porous material (292) having a continuous pore structure, and a fluorine-based porous part (293) formed by fusing fluorine-based particles to each other. The fluorine-based porous part (293) is fused to the inorganic porous material (292) in pores (294) of and on the outer surface (295) of the inorganic porous material (292). This makes it possible to provide the liquid-repellent layer (29) that is a functional porous material having desired mechanical strength, gas permeability, and liquid impermeability.