A Ruddlesden-Popper oxide as a carbon dioxide tolerant cathode for solid oxide fuel cells that operate at intermediate temperatures

Solid oxide fuel cells (SOFCs) that operate at intermediate temperatures of 600 to 800 degrees C have recently received increased attention due to their improved durability, more rapid startup and shutdown, better sealing and lower cost than their counterparts operate at high temperatures. Nevertheless, intermediate-temperature SOFCs (IT-SOFCs) with popular perovskite cathodes contain alkaline-earth elements, which are prone to reaction with carbon dioxide (CO2), even when the CO2 content is comparatively low. In this work, an alkaline-earth metal-free Ruddlesden-Popper oxide, Nd1.8La0.2Ni0.74Cu0.21Ga0.05O4+delta (NLNCG), is developed for IT-SOFC cathodes. The cell is based on an electrolyte with 8% (mol) Y2O3-stabilized ZrO2 (8YSZ). The NLNCG cathode exhibits an excellent CO2 tolerance, as proven by thermogravimetry analysis, in situ X-ray diffraction, I-V-P test, and electrochemical impedance spectroscopy (EIS), and stability measurements. The anode-supported single-cell NiO-YSZ|YSZ|NLNCG outputs a peak power density of 0.522 W center dot cm(-2) at 800 degrees C. These findings suggest that NLNCG could be a highly suitable cathode material with CO2 tolerance for IT-SOFCs. (c) 2022 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights reserved.

Automated summary

Solid oxide fuel cells (SOFCs) operating at intermediate temperatures have attracted attention due to their improved durability, rapid startup and shutdown, better sealing, and lower cost. This work develops an alkaline-earth metal-free Ruddlesden-Popper oxide for intermediate-temperature SOFC cathodes, which exhibits excellent CO2 tolerance and potential for application in IT-SOFCs.