Composite air electrode and associated manufacturing method

A method for manufacturing a composite electrode configured to be used in a metal-air electrochemical cell with a liquid electrolyte of basic pH, the method comprising:

• obtaining an air electrode porous structure comprising an outer surface, the porous structure being configured to facilitate an oxygen reduction reaction into hydroxyl ions in the presence of an electric current;
• synthesizing a first liquid solution comprising a fluoropolymer suspended in a solvent, the fluoropolymer being capable of forming a membrane impermeable to at least the liquid electrolyte of basic pH, the fluoropolymer comprising SO2N groups capable of conducting hydroxyl ions and wherein the fluoropolymer comprises a fluorinated backbone chain with polar groups that are at least partially hydrogenated;
• applying the first liquid solution at least once onto the outer surface of the porous structure, the solvent flowing through the porous structure and the fluoropolymer being deposited by aggregating into a layer on the outer surface of the porous structure, thereby forming said membrane impermeable to at least the liquid electrolyte of basic pH and conductive to hydroxyl ions.