Ultrafast high-temperature sintering of yttrium-doped barium zirconate ceramics

Barium zirconate doped with 20 mol% yttrium (BaZr0.8Y0.2O3-δ) is a promising electrolyte for protonic solid-state electrochemical cells. Its application is, however, limited by the high sintering temperature (usually ≈1600°C for about 24 h), which causes barium volatilization, making the stoichiometry control challenging. As such, barium zirconates are typically sintered within a sacrificial powder bed to avoid the loss of barium, which increases the costs and the complexity in the sintering process. In the present work, Ultrafast High-temperature Sintering (UHS) is employed to enable full densification of BaZr0.8Y0.2O3-δ in less than 6 min. Even though the small grain size and the high Schottky barrier limit the performance at low temperatures, the produced components by UHS feature a total conductivity of 0.01 S cm-1 above 550°C. This study demonstrates a rapid sintering proof-of-concept for the fabrication of high-performance BaZr0.8Y0.2O3-δ without the use of sacrificial powder.