(Invited) Applications of Protonic Ceramics for Electrochemical Energy Conversion and Storage

Recent exciting advancements in proton-conducting ceramic materials and devices suggest that they are approaching a technology readiness level that rivals more well-established polymeric and oxygen-ion conducting counterparts. Because they can enable proton-mediated electrochemistry under both dry and wet environments at moderate temperatures, protonic ceramics provide unique opportunities to enhance or synergize a diverse range of complementary electrochemical and thermochemical processes. Because of this potential, significant efforts have been devoted to advancing numerous energy-related applications using these materials. Here, we will provide an overview of recent research efforts at the Colorado School of Mines focused on developing protonic ceramics for a number of applications, including: Hydrocarbon-tolerant protonic ceramic fuel cells for electricity generation (PCFCs) Protonic ceramic electrolyzers for fuel synthesis (PCECs) Reversible protonic-ceramic electrochemical cells for energy storage (RePCECs). Recent progress has lead to remarkably high-performance H2 and hydrocarbon-fueled PCFCs; exceptionally efficient (>97% LHV efficiency) PCECs for H2 production and for the co-conversion of steam and carbon dioxide to renewable methane; H2/H2O-based RePCECs with >75% round-trip efficiency (cell-level) for seasonal energy storage, and a reversible ammonia fuel cell for ammonia synthesis/power production. In addition, ongoing collaboration with industrial partners demonstrates promising scale-up and durability progress for protonic ceramic cells and stacks that underscores their potential for eventual commercial application. Acknowledgements: This work was supported by the Advanced Research Projects Agency-Energy (ARPA-E) through the REFUEL (Award No. DEAR0000808) and REBELS programs (Award No. DE-AR0000493) and the Office of Fossil Energy (Award No. DE-FE0031716). Additional support was provided by the Army Research Office under Grant No. W911NF-17-1-0051, the Office of Naval Research via Grant No. N00014-16-1-2780, and faculty research funding from Kansas State University.