Effect of lithium fluoride on thermal stability of proton-conducting Ba(Zr0.8−xCexY0.2)O2.9 ceramics
Abstract In-situ X-ray diffraction (XRD) and micro-Raman scattering have been used to study the thermal stability of lithium fluoride (LiF)-added (7% weight ratio) Ba(Zr 0.8− x Ce x Y 0.2 )O 2.9 (BZCY: x  = 0.1 and 0.2) proton-conducting ceramic powders as a function of temperature in 1 atm of flowing CO 2 . This work reveals that LiF-addition can reduce the thermal stability of Ba(Zr 0.8− x Ce x Y 0.2 )O 2.9 in CO 2 and cause decomposition to BaCO 3 , and possibly Ba 3 Ce 2 (CO 3 ) 5 F 2 (or CeCO 3 F), and Y 2 O 3 -like compound after exposure to CO 2 from high temperatures. LiF-related compounds can be removed after calcining (or sintering) in air above 1200 °C, but a minor amount of a Y 2 O 3 -like compound could remain after calcining at 1400 °C in air.