5. Zinc-air batteries

5.1 General

Zinc-air batteries have been around for over a hundred years, but practical applications didn't really come to fruition until the early 1930s, when Heise & Schumacher in 1932 used a porous carbon structure as an air electrode. The use of a hydrophobic tar enabled them to avoid the progressive flooding observed with air electrodes featuring porous carbon structures [7] . One of the great advantages of zinc-air batteries is that the cathodic reactive compound, oxygen, is not contained in the battery but in the surrounding air, freeing up space and mass to put in a larger quantity of anodic compound and achieve high mass energies. However, the space freed up can only be significant if the discharge rates...