Enhancing the flash-sinterability of BaZr0.1Ce0.7Y0.2O3-δ proton-conducting electrolyte by nickel oxide doping for possible application in SOFCs

• Published in: International journal of hydrogen energy Vol. 46; no. 19; pp. 11115 - 11126
• Main Authors: Soleimany, Mehrzad, Paydar, M.H., Wang, Shaorong
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 16.03.2021
• Subjects: Flash sintering; Impedance spectroscopy; NiO Additive; Proton conductor; SOFCs; NiO Additive; Impedance spectroscopy; SOFCs; Proton conductor; Flash sintering
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2020.06.112

In the present work, effects of nickel oxide doping on flash-sinterability of BaZr0.1Ce0.7Y0.2O3-δ compound were investigated. A single-phase BZCY7 powder was synthesized by the solid-state reaction route. The effects of using 0.5, 1, 1.5, and 2 wt% of NiO additive on flash sintering of BZCY7 samples were examined. It was revealed that using 0.5 wt% of NiO additive can reduce the onset temperature of flash sintering in all the applied electric fields in the range of 100–500 V/cm and significantly enhances the sinterability of the BZCY7 compound. Microstructural investigations, using field emission scanning electron microscopy and energy-dispersive X-ray mapping, showed that NiO doping can lead to larger grain sizes, while no detectable segregation or second phase was observed. Utilizing electrochemical impedance spectroscopy, the total conductivity of samples at 600 and 700 °C was measured as 4.4 × 10−3 and 7.0 × 10−3 S/cm for the undoped BZCY7, and 8.6 × 10−3 and 1.4 × 10−2 S/cm for the 0.5 wt% NiO doped BZCY7 sample, respectively. The activation energies of conduction were determined as 0.37 and 0.41 eV for the doped and undoped samples, which represent the presence of predominant and facile protonic conduction. •A single-phase BZCY7 compound was synthesized.•The effects of NiO addition on flash sintering of the samples were investigated.•Using 0.5 wt% NiO additive, the flash-sinterability of the compound was enhanced.•NiO doping improved the proton conductivity of the flash-sintered BZCY7 sample.