Kang Xu , Hua Zhang , Yangsen Xu , Dongliang Liu , Feng Zhu , Fan He , Ying Liu , Haobing Wang , Yu Chen
{"title":"Phase engineering of a donor-doped air electrode for reversible protonic ceramic electrochemical cells","authors":"Kang Xu , Hua Zhang , Yangsen Xu , Dongliang Liu , Feng Zhu , Fan He , Ying Liu , Haobing Wang , Yu Chen","doi":"10.1016/j.apmate.2024.100187","DOIUrl":null,"url":null,"abstract":"<div><p>Reversible protonic ceramic electrochemical cells (R-PCECs) demonstrate great feasibility for efficient energy storage and conversion. One critical challenge for the development of R-PCECs is the design of novel air electrodes with the characteristics of high catalytic activity and acceptable durability. Here, we report a donor doping of Hf into the B-site of a cobalt-based double perovskite with a nominal formula of PrBa<sub>0.8</sub>Ca<sub>0.2</sub>Co<sub>1.9</sub>Hf<sub>0.1</sub>O<sub>5+<em>δ</em></sub> (PBCCHf<sub>0.1</sub>), which is naturally reconfigured to a double perovskite PrBa<sub>0.8-<em>x</em></sub>Ca<sub>0.2</sub>Co<sub>1.9</sub>Hf<sub>0.1-<em>x</em></sub>O<sub>5+<em>δ</em></sub> (PBCCHf<sub>0.1-<em>x</em></sub>) backbone and nano-sized BaHfO<sub>3</sub> (BHO) on the surface of PBCCHf<sub>0.1−<em>x</em></sub>. The air electrode demonstrates enhanced catalytic activity and durability (a stable polarization resistance of 0.269 Ω cm<sup>2</sup> for ∼100 h at 600 °C), due likely to the fast surface exchange process and bulk diffusion process. When employed as an air electrode of R-PCECs, a cell with PBCCHf<sub>0.1</sub> air electrode demonstrates encouraging performances in modes of the fuel cell (FC) and electrolysis (EL) at 600 °C: a peak power density of 0.998 W cm<sup>−2</sup> and a current density of −1.613 A cm<sup>−2</sup> at 1.3 V (with acceptable Faradaic efficiencies). More importantly, the single-cell with PBCCHf<sub>0.1</sub> air electrode demonstrates good cycling stability, switching back and forth from FC mode to EL mode ±0.5 A cm<sup>−2</sup> for 200 h and 50 cycles.</p></div>","PeriodicalId":7283,"journal":{"name":"Advanced Powder Materials","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2024-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772834X24000186/pdfft?md5=98f8d0c61d6bcec1879838acced93dd5&pid=1-s2.0-S2772834X24000186-main.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Advanced Powder Materials","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2772834X24000186","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Reversible protonic ceramic electrochemical cells (R-PCECs) demonstrate great feasibility for efficient energy storage and conversion. One critical challenge for the development of R-PCECs is the design of novel air electrodes with the characteristics of high catalytic activity and acceptable durability. Here, we report a donor doping of Hf into the B-site of a cobalt-based double perovskite with a nominal formula of PrBa0.8Ca0.2Co1.9Hf0.1O5+δ (PBCCHf0.1), which is naturally reconfigured to a double perovskite PrBa0.8-xCa0.2Co1.9Hf0.1-xO5+δ (PBCCHf0.1-x) backbone and nano-sized BaHfO3 (BHO) on the surface of PBCCHf0.1−x. The air electrode demonstrates enhanced catalytic activity and durability (a stable polarization resistance of 0.269 Ω cm2 for ∼100 h at 600 °C), due likely to the fast surface exchange process and bulk diffusion process. When employed as an air electrode of R-PCECs, a cell with PBCCHf0.1 air electrode demonstrates encouraging performances in modes of the fuel cell (FC) and electrolysis (EL) at 600 °C: a peak power density of 0.998 W cm−2 and a current density of −1.613 A cm−2 at 1.3 V (with acceptable Faradaic efficiencies). More importantly, the single-cell with PBCCHf0.1 air electrode demonstrates good cycling stability, switching back and forth from FC mode to EL mode ±0.5 A cm−2 for 200 h and 50 cycles.