Electrochemical performance of La0.6Sr0.4CoO3-δ cathode in air and wet air for BaCe0.54Zr0.36Y0.1O3-based proton-conducting solid oxide fuel cell

Abstract

Solid oxide fuel cell (SOFC) electrodes often suffer from degradation resulting from different contaminations such as water vapour from air during high-temperature operation. Thus, humidity-resistant electrode materials must be developed for SOFC application. In this work, La0.6Sr0.4CoO3-δ (LSC) material is prepared by sol-gel method and evaluated as a potential cathode to be operated with proton-conducting electrolyte of BaCe0.54Zr0.36Y0.1O3 (BCZY) at intermediate temperature (500 – 800 °C). An LSC|BCZY|LSC symmetrical cell is fabricated by screen printing an LSC cathode ink onto a BCZY electrolyte pellet. The electrochemical performance of the LSC cathode for the fabricated symmetrical cell in air and wet air is characterised using an electrochemical impedance spectroscopy (EIS) analyser. EIS results revealed that the area specific resistance value of the LSC cathode in wet air is lower than that in air at temperatures ranging from 600 °C (0.35 Ω cm2) to 800 °C (0.06 Ω cm2) with a low value of activation energy (0.70 eV). Hence, the LSC cathode exhibits better electrocatalytic activity and performance in wet air than in air. This work suggests that the LSC material meets the requirements for application as a cathode in intermediate-temperature proton-conducting SOFC based on BCZY electrolyte.