“Beyond Li-ion” energy storage solutions based on ions such as Na, Mg, Ca, and Zn have attracted increasing attention due to growing concerns about the cost, resource availability, and safety of the currently dominant Li-ion batteries. One of the greatest challenges for beyond-Li systems, especially multivalent ones, is the lack of materials with high ionic mobility. In this study, we find that zircon-type YPO4 presents a unique structural environment that enables superior conduction of multiple species including Na+, Ca...