Fabrication and properties of Ba(Zr1−xCex)0.9Y0.1O2.95/NaCl composite electrolyte materials

► Small amount of BaCeO3 was added to BaZrO3 to partially overcome its shortcomings. ► ZnO was used to lower the sintering temperature of Ba(Zr1−xCex)0.9Y0.1O2.95. ► NaCl, as the second phase, is homogeneously dispersed along the grain boundary. ► It transformed to a super-ionic phase to enhance the proton migration rate. ► Electrochemical performances of the composite are improved.