Glass ceramics separators for Lithium-Air Batteries with an aqueous alkaline electrolyte

Schott „LAGP“ shows the highest ionic conductivity (2.4·10-4 [S(cm²)-1]) while “Gen-1“ shows the lowest ionic conductivity (1.0·10-5 [S(cm²)-1]). This lower ionic conductivity is caused by a higher grain boundary resistance due to absence of germanium in the „Gen-1“ glass ceramic. All glass ceramics show a color change at the contact spots with metallic lithium. XRD patterns of these black colored spots show titanium which indicates a possible reduction of titanium oxide to titanium within the material. The water permeation rate of the tested Ohara glass ceramic separator is 8.172·10-6 [g (h·m²)-1]. This is six orders of magnitude lower than the water permeation rate of a Sigracet® GDL 35 DC used for example in a PEM fuel cell which was used for comparison