Low-temperature zinc-sulfur battery

High-temperature sulfur batteries, for example the sodium-sulfur battery, a re well known. However, the positive electrode based on elementary sulfur a t room temperature in a metal-sulfur battery could not be constructed becau se sulfur is known to be an excellent insulator. Due to its low atomic weig ht, its low cost and its non-toxicity, sulfur would be a desirable material for batteries. We could show that elementary sulfur is an excellent cathod e material at room temperature as it is reduced rapidly in aqueous solution s on the surface of iron sulfide electrodes. The open-cell voltage of a zin c-sulfur battery is about 0.6 V, that of a lithium-sulfur battery about 2.5 V. The capacities and specific energies exceed those of commercially avail able zinc-manganese dioxide batteries. In this context the electrochemical reaction of solid elementary sulfur on iron sulfide surfaces in sea water i s discussed which could have been one of the energy sources which played a role in the development of life.