Significantly improving the durability of single-chamber solid oxide fuel cells : a highly active CO₂-resistant perovskite cathode

Abstract

The single-chamber solid oxide fuel cell (SC-SOFC) represents an attractive alternative to batteries for micropower applications given its simplified stack design, easy gas management, lower operation temperature, and quicker start-up. Its stable operation over long duration relies on the availability of CO2-resistant cathode materials with high oxygen reduction reaction (ORR) activity. Here, we reported a novel perovskite oxide cathode SrSc0.075Ta0.025Fe0.9O3−δ (SSTF75), which provides CO2 resistance and high ORR activity. A peak power density of 1430 mW cm–2 was achieved with the SSTF75/Sm0.2Ce0.8O1.9 cathode at 650 °C with a methane and oxygen gas mixture (1:1 v/v ratio). It retained stable voltage performance at 600 °C for an over 90 h duration when discharged at a current density of 1000 mA cm–2. This work not only represents an advancing step in the SC-SOFC field but also authenticates an effective codoping strategy for the design of a CO2-resistant cathode for low-temperature applications.