Recent Advancements in Materials for Proton-Conducting Reversible Solid Oxide Cells

Abstract

The escalating threats posed by climate change and environmental issues underscore the need for urgent exploration of clean energy technologies. In this context, proton-conducting reversible solid oxide cells (P-RSOCs) have emerged as promising contenders for large-scale energy storage and conversion. Their efficacy at intermediate temperatures (400 - 600 °C) is a distinctive advantage, attributed to the remarkable ionic conductivity of proton conductors within this temperature range. This feature positions P-RSOCs favorably for the efficient, cost-effective, and enduring conversion between clean electricity and green hydrogen.However, the successful commercialization of P-RSOCs hinges on the rational design of novel materials and meticulous surface/interface modifications to significantly enhance performance and durability. Achieving prolonged durability during cycling between fuel cell and electrolysis modes while maintaining high Faraday efficiency and roundtrip energy efficiency is of paramount importance. A central challenge involves the development of electrolyte materials exhibiting exceptional stability and a high ionic transference number under operating conditions. Additionally, bifunctional electrodes/catalysts, particularly for the oxygen electrode, must demonstrate elevated activity for efficient dual-mode operation.To effectively tackle these challenges, it is imperative to devise new protocols for controlling the structure, composition, and morphology of materials across multiple length scales. Equally crucial is gaining a fundamental understanding of degradation mechanisms and electrode processes. This presentation will illuminate the critical scientific challenges inherent in developing a new generation of P-RSOCs, providing insights into the latest advancements in electrolyte materials and bifunctional electrodes/catalysts. Furthermore, it will highlight strategies for enhancing durability and electrode activity through surface/interface modification, along with the latest developments in modeling, simulation, and in situ characterization techniques to deepen our understanding of the underlying mechanisms. The presentation will conclude prospects for achieving low-cost, highly efficient, and durable P-RSOCs through innovative material-based solutions.