Аннотация:Thermal stability of a protonated form of BaMn6O24 tunnel phase was investigated for the first time as the one, wich it may serve as an effective ion exchange matrix, when developing the new types of batteries. It was found, that irreversible structure destruction takes place near 450°C, thus limiting a thermal range available for functioning of this one-dimentional proton conductor, demonstrating, nevertherless, the high level of mixed conductivity even at room temperature.48