A new Br− anion-conducting solid electrolyte with a low solubility in water and a high thermal stability at elevated temperatures was developed by selecting LaOBr as a mother solid electrolyte phase. By the partial substitution of La3+ site in LaOBr with divalent Ca2+ or Sr2+, the bromide anion conductivity was greatly enhanced, and the highest Br− ion conductivity of 1.9 x 10−3 and 1.2 x 10−4S/cm was obtained at 873K for La0.9Sr0.1OBr0.9 and La0.9Ca0.1OBr0.9, respectively. The Br− anion conduction in La0.9M0.1OBr0.9 (M = Ca, Sr) was directly demonstrated by DC electrolysis.

Br− Anion-Conducting Properties in La1−xMxOBr1−x Solid (M = Ca, Sr). Y.Kato, N.Imanaka: Solid State Ionics, 2004, 175[1-4], 455-8