Highly Stable Protonic Ceramic Electrolysis Cells Based on Air Electrodes with Finger-Like Pores Current Collection Layers Running in High-Steam-Content Air

Zhengfeng Wang; Xiaoyun Miao; Xiaofeng Ye; Zhaoyin Wen

doi:10.1021/acsami.3c10393

Highly Stable Protonic Ceramic Electrolysis Cells Based on Air Electrodes with Finger-Like Pores Current Collection Layers Running in High-Steam-Content Air

ACS Appl Mater Interfaces. 2023 Sep 27;15(38):45035-45044. doi: 10.1021/acsami.3c10393. Epub 2023 Sep 13.

Authors

Zhengfeng Wang^{1

2}, Xiaoyun Miao^{1

3}, Xiaofeng Ye^{1

3}, Zhaoyin Wen^{1

3}

Affiliations

¹ State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050, P. R. China.
² College of Chemistry and Materials Science, Shanghai Normal University, Shanghai 200234, P. R. China.
³ Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, 19 A Yuquan Road, Shijingshan, Beijing 100049, P. R. China.

PMID: 37704019
DOI: 10.1021/acsami.3c10393

Abstract

The steam content in the air electrode is one of the major factors determining the efficiency and stability of protonic ceramic electrolysis cells (PCECs). In this work, the La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ (LSCF) current collection layer (CCL) film with unique finger-like pores was successfully prepared by the phase-inversion tape-casting technique (PT), which promoted the gas diffusion inside the electrode and effectively improved the stability of the single cell in high-humidity air. A screen-printed LSCF-BaCe_0.7Zr_0.1Y_0.1Yb_0.1O₃ catalytic active layer (CAL) was also applied to match the thermal expansion coefficient (TEC) values and improve the interface combination. The electrochemical impedance spectroscopy (EIS) and distribution of relaxation time (DRT) studies of the symmetric cells showed that when the film was used to match different CALs as an air electrode, the gas diffusion inside the electrode was no longer restricted by the increasing steam content in air. The single cell exhibited a high electrolysis current density of 1 A cm^-2 (1.25 V) at 650 °C; furthermore, no performance degradation was observed in this high current density when electrolyzed in air with 40 and 60% humidity for more than 250 h. These results present a simplified and economical scheme to develop air electrodes with high stability in wet air with a high steam content.

Keywords: air electrode; current collection layer; high-humidity air; phase-inversion tape casting; stability.