Development status of high temperature proton conductors as solid oxide fuel cells/electrolysis cells materials: experimental and computational approaches

Abstract

High temperature solid oxide proton conductors are promising materials for both solid oxide fuel cell (SOFC) and solid oxide electrolysis cells (SOEC). In this paper, the development history and future prospects of the proton conductors are reviewed. In section 1, features and challenges of oxide ion and proton conductive SOFC/SOEC are described based on their working mechanisms. In section 2, proton conductive mechanism is explained. In section 3, history and the current status of proton conductor development is described. In section 4, the effect of adding proton conductors into the fuel electrode of oxide ion conductive SOFC is explained. In the section 5, we briefly summarize computational approaches suitable for the modeling of solid proton conductors are introduced. So far, many proton conductors have been developed focusing on perovskite or perovskite related structures. However, the practical application is still difficult. To achieve higher performance, in particular proton conductivity and stability, other types of materials should also be explored. Understanding proton conduction in solid oxides with the help of computations will help rational design of novel proton conductors. Better quantitative evaluation methods of the effect of proton conductor addition into fuel electrodes will be also developed.