Mixed ionic-electronic conducting (MIEC) membranes have gained growing interest recently for various promising environmental and energy applications, such as H2 and O2 production, CO2 reduction, O2 and H2 separation, CO2 separation, membrane reactors for production of chemicals, cathode development for solid oxide fuel cells, solar-driven evaporation and energy-saving regeneration as well as electrolyzer cells for power-to-X technologies. The purpose of this roadmap, written by international specialists in their fields, is to present a snapshot of the state-of-the-art, and provide opinions on the future challenges and opportunities in this complex multidisciplinary research field. As the fundamentals of using MIEC membranes for various applications become increasingly challenging tasks, particularly in view of the growing interdisciplinary nature of this field, a better understanding of the underlying physical and chemical processes is also crucial to enable the career advancement of the next generation of researchers. As an integrated and combined article, it is hoped that this roadmap, covering all these aspects, will be informative to support further progress in academics as well as in the industry-oriented research toward commercialization of MIEC membranes for different applications.

Artikel-ID 2105702 G.C. and A.W. acknowledges funding by the German Federal Ministry of Education and Research in the framework of the “Kopernikus projects for the Energiewende”. (DFG; German Research Foundation) – 435833397. X.Y.W. was supported by the Start-up Grant of University of Waterloo. X.Z. and Y.W. appreciate the financial supports from the National Natural Science Foundation of China (21776267), Dalian National Laboratory for Clean Energy (DICP&QIBEBT UN201708), and LiaoNing Revitalization Talents Program (XLYC1801004). J.X. and H.W. gratefully acknowledge the funding from the Natural Science Foundation of China (22075086), the Guangdong Basic and Applied Basic Research Foundation (2020A1515011157) and the PetroChina Innovation Foundation (2019D-5007-0406). Z.S. would like to thank the Australia Research Council for supporting the project under contract DP150104365 and DP160104835. K.S.B. and J.D. acknowledge financial supported by the National Energy Technology Laboratory (NETL) and Oak Ridge Institute for Science and Education (ORISE). K.S.B. was supported in part by an appointment to the NETL Research Participation Program, sponsored by the U.S. Department of Energy and administered by the Oak Ridge Institute for Science and Education. Y.Z. and H.J. gratefully acknowledge the funding from the Natural Science Foundation of China (21676284, 22175193). S.L. thanks the Fundamental Research Fund for the Central University (Buctrc202115). X.T. acknowledges the financial support provided by the National Natural Science Foundation of China (91745116). R.K. thanks Dr. Robert Kircheisen for the evaluation of pilot plant test data and Dr. Robert Hoffmann for the membrane manufacturing as well as analyzing and optimizing the membrane manufacturing costs. Open access funding enabled and organized by Projekt DEAL.