Abstract: A metal-air battery or fuel cell comprising a metal or metal hydride anode, an aqueous liquid electrolyte containing an ion conducting material, and an air electrode which allows ingress and egress of oxygen and which contains one or more catalysts capable of evolution and/or reduction of oxygen, wherein the air electrode has both hydrophobic and hydrophilic pores, the hydrophilic pores are at least partially filled with aqueous liquid electrolyte and the air electrode and/or the electrolyte comprises hygroscopic material and OH? ions, whereby water vapour exchange with the environment is limited. The hygroscopic material is used to control the humidity of the system.

Abstract: Air electrodes for secondary metal-air batteries or secondary metal hydride-air batteries, in particular, bifunctional air electrodes that can undergo oxygen reduction and oxygen evolution with high reaction rates. A method of manufacturing such electrodes.

Abstract: Zinc electrodes for use in batteries, the electrode containing an organic gelling agent, an organic binding agent, calcium zincate and an electro-active element. A method of manufacturing such electrodes, and use of such electrodes in primary and secondary batteries.