A short review on triple conducting oxide cathode materials for proton conducting solid oxide fuel cell

Abstract

The performance of solid oxide fuel cells (SOFCs) is significantly affected by the properties of its components which are electrolyte, electrodes (cathode and anode) and interconnect. Among the components, cathode is considered as the most critical component as high cathode polarization resistance (Rp) contributes to a major loss in SOFC performance. Thus, developing of good materials as cathode has been attempted to cater the problem. The development of cathode materials for SOFCs started with pure electronic conductor. This type of cathode materials provides limited electrochemical reaction sites, resulting in high Rp. Next, mixed ionic-electronic conductor (MIEC) cathode materials have been developed and followed by composite cathode materials. Both types of cathode materials are better than pure electronic conductor as they provide larger electrochemical reaction sites. However, some of them still resulting in high Rp especially at operating temperatures ranging from 400 °C to 800 °C. Then, the current researches are devoted to develop triple-conducting (H+/O2-/e-) oxide (TCO) cathode materials. This type of cathode materials is particularly useful for proton-conducting SOFC application. Therefore, this paper aims to provide a short review on the properties and performance of the TCO cathode materials along with the factors influencing its properties and performance.