ChemInform Abstract The results of static immersion corrosion tests in various polysulfides (i.e., Na2S3, Na2S4, Na2S5) and sulfur show that Al is not compatible with the discharged state of the positive electrode of the sodium/sulfur cell and that the corrosion product in sulfur is only Al3S3. The results are discussed in terms of results previously reported for the corrosion of Al in sodium/sulfur cells.