Negative electrode for metal-air battery

Abstract

In a metal negative electrode, a current collector includes a through-hole or a recess provided to extend from a front surface of a planar plate toward a back surface of the planar plate. A distance from a midpoint of a joining boundary to a point on a surface of the current collector is designated as a region dividing distance, the point defining a distance less than a maximum distance between the midpoint and a side or a surface of the current collector. In the current collector, a first region is a region defined by distances from the midpoint, the distances being a distance equal to the region dividing distance and distances greater than the region dividing distance, and, in the current collector, a second region is a region defined by distances from the midpoint that are less than the region dividing distance. A volume reduction ratio of the first region is greater than a volume reduction ratio of the second region, the volume reduction ratio of the first region being a ratio with respect to a volume of the first region determined assuming that the through-hole or the recess is not present, the volume reduction ratio of the second region being a ratio with respect to a volume of the second region determined assuming that the through-hole or the recess is not present.