Rapid Gas-Phase Synthesis of the Perovskite-Type BaCe0.7Zr0.1Y0.1Yb0.1O3-δ Proton-Conducting Nanocrystalline Electrolyte for Intermediate-Temperature Solid Oxide Fuel Cells

Zeyun Wu; Yiyang Zhang; Zuoqing Liu; Haorui Ma; Xing Jin; Guangming Yang; Yixiang Shi; Zongping Shao; Shuiqing Li

doi:10.1021/acsami.2c11492

Rapid Gas-Phase Synthesis of the Perovskite-Type BaCe_0.7Zr_0.1Y_0.1Yb_0.1O_3-δ Proton-Conducting Nanocrystalline Electrolyte for Intermediate-Temperature Solid Oxide Fuel Cells

ACS Appl Mater Interfaces. 2022 Oct 26;14(42):47568-47577. doi: 10.1021/acsami.2c11492. Epub 2022 Oct 13.

Authors

Zeyun Wu¹, Yiyang Zhang², Zuoqing Liu³, Haorui Ma¹, Xing Jin⁴, Guangming Yang³, Yixiang Shi¹, Zongping Shao³, Shuiqing Li¹

Affiliations

¹ Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Energy and Power Engineering, Tsinghua University, Beijing 100084, China.
² Key Laboratory of Advanced Reactor Engineering and Safety of Ministry of Education, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China.
³ State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing 211816, China.
⁴ State Key Laboratory of Multi-Phase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.

PMID: 36228663
DOI: 10.1021/acsami.2c11492

Abstract

Perovskite-type proton-conducting materials, such as BaCe_0.7Zr_0.1Y_0.1Yb_0.1O_3-δ (BCZYYb), are very attractive for the next-generation equipment of electrochemical energy conversion and storage owing to their excellent conductivity in the intermediate-temperature range (300-750 °C), as well as good thermo-chemical stability, coking resistance, and sulfur tolerance. However, the lack of a reliable and cost-effective synthesis method for such multi-component co-doping oxides limits their large-scale application. In this study, for the first time, we successfully synthesize BCZYYb electrolyte nanopowders by using a rapid, scalable flame-based gas-phase synthesis method with two different barium precursors Ba(NO₃)₂ and Ba(CH₃COO)₂, named as BCZYYb (N) and BCZYYb (CA). The as-synthesized nanoparticles exhibit good crystallinity of the pure orthorhombic perovskite BCZYYb phase. BCZYYb (CA) shows more uniform doping with the element ratio of 1:0.74:0.12:0.08:0.1, which is very close to the theoretical value. The shrinkage and surface SEM (scanning electron microscope) results indicate that the flame-made powders have superior sinterability compared to the sol-gel-made powders because of the smaller primary particle size (∼20 nm). Electrochemical impedance spectroscopy tests show that BCZYYb (CA) sintered at 1450 °C has the highest protonic conductivity of 1.31 × 10^-2 S cm^-1 in wet H₂ when operating at 600 °C and still maintains a high-level conductivity of 1.19 × 10^-2 S cm^-1 even when the sintering temperature is reduced to 1350 °C, which is mainly attributed to uniform doping and good sinterability. The activation energy for the conductivity of BCZYYb (CA) is also significantly lower than that of conventional electrolytes, which suggests much better conductivity in the intermediate (∼600 °C) and even lower operating temperature. The excellent conductivity performance combined with the high-throughput production capability makes the swirling spray flame a promising synthesis method for promoting the BCZYYb electrolytes from lab to industrial-scale solid oxide fuel cells.

Keywords: intermediate-temperature SOFCs; nanocrystalline BCZYYb proton-conducting electrolyte; protonic conductivity; sintering behavior; spray flame synthesis.