Intermediate Temperature Solid Oxide Cell with a Barrier Layer Free Oxygen Electrode and Phase Inversion Derived Hydrogen Electrode

Abstract

High-temperature solid oxide cells (SOCs) have fundamental advantages in efficiency and product rate over their low-temperature counterparts. However, the commercial development of SOCs is hindered by cost and reliability. To solve the issues, lowering the operating temperature of SOCs is deemed the best solution. Here we report on our effort toward intermediate temperature (IT) SOCs by developing a barrier layer free high-performance oxygen electrode and open structured hydrogen electrode. The results show that the new oxygen electrode provides reasonably good oxygen electrocatalytic activity at IT range for oxygen reduction and evolution reactions and the open structured hydrogen electrode provides low gas diffusion path for H2/H2O. However, at high electrolysis current density such as 1A/cm2 and 650oC, the present oxygen electrode delaminates after 200 hours. The phase-inversion derived open structured hydrogen electrode helps gas diffusion but, in the meantime, reduces reactive sites. A proper balance of porosity and number of reactive sites is still needed for future hydrogen electrode development.

Proton‐Mediated and Ir‐Catalyzed Iron/Iron‐Oxide Redox Kinetics for Enhanced Rechargeability and Durability of Solid Oxide Iron–Air Battery

“…Battery Fabrication, Assembly, and Testing: For RSOC, the fuel electrode-supported electrolyte half-cell was fabricated by dry-pressing and dip-coating method as described before. [30] Briefly, a mixture of NiO (Inframat Advanced Materials), (Sc 2 O 3 ) 0.1 (CeO 2 ) 0.01 (ZrO 2 ) 0.89 (ScSZ, Daiichi Kigenso Kagaku Co. Ltd., Japan), and graphite with a weight ratio of 60:40:30 was mixed with ethanol in a planetary mill for 2 h followed by drying at 80 °C overnight. The dried powders were then fully mixed with 5 wt% PVB in acetone with an agate mortar, followed by pressing into 𝛷1.0′′ pellets and partially sintering at 900 °C for 2 h to achieve enough strength.…”

Evaluation of steam supply performance: Steamer vs. bubbler

“…A stable and accurate supply of steam can ensure smooth operation of electrolyzers, precise determination of electrolysis performance (e.g., Faradaic efficiency) and identification of the root causes of any cell anomalies. Currently, three types of steam generators have been devised to provide steam for SOECs: 1) bubbler (O'Brien et al, 2007;Zhang et al, 2013;Schefold et al, 2017), 2) steamer (Kim-Lohsoontorn and Bae, 2011;Shen et al, 2022;Zhang et al, 2022), and 3) hydrogen-burner (Hauch et al, 2005). The bubbler is the most popular design, by which a carrier gas is passed through and exits with saturated steam.…”