An air electrode providing high current density for metal-air batteries

摘要

An air electrode for electrochemical cells provides high current capability over prior art cathodes. The electrode has an active layer of a carbon matrix with an oxygen reduction catalyst and a fluoropolymer binder. An embedded current collector is coated with a conductive material including a polymer binding agent and a conductive material, preferably of carbon. The coated current collector is baked to sinter the binder and establish a continuous conductive hydrophobic coating on the current collector. The active layer has a low density, preferably less than 1 g/cc. The electrode is a multilayer structure with a separator on one side of the active layer and a highly porous Teflon guard layer on the other side. The guard layer preferably has a porosity of at least 30 % and a thickness of no more than 100 microns.