Abstract: An air cathode having a multilayer structure is composed of at least one substrate, two diffusion layers and three activation layers. The two diffusion layers are laminated over an upper side of the substrate and a lower side of the substrate. The three activation layers are respectively laminated over one of the two diffusion layers in order. Different loadings or different kinds of catalysts are added into a slurry to form the activation layers, and the activation layers and the diffusion layers are made through simultaneous sintering, thereby shortening the processing time. When the air cathode is used as the cathode of the Zinc-Air battery, the electrolyte inside the Zinc-Air battery will not be influenced by the outside air, and the problem of maintaining the water content of the zinc anode of the Zinc-Air battery can be efficiently overcome.

Abstract: An air cathode having multiple layered structure formed by at least a layer of base material, two sintered diffusion layers and a sintered activation layer in laminating shape wherein the base material is as the electric current collector which is made of metal wire net or metal foam net carrying at least two sintered diffusion layers made of hydrophobic carbon material by sintering attached to upper and bottom side in laminating shape; additionally, one of the sintered diffusion layer on the base material carries at least one sintered activation layer which is made of hydrophilic carbon material carrying transition metal oxide catalyst; the air cathode shall be used as a cathode for Zn/Air cell, Fuel Cell or electric capacitor particularly to prevent electrolytic solution from being affected by the environment air outside the Zn/Air cell and to enable the Zn/Air cell under dry environment condition to maintain a stable electric property for a long period of time.