PART 1: NON-TECHNICAL SUMMARY The operation of batteries critically relies on the movement of charged ions through an electrolyte medium. If solids could be used as electrolyte rather than the flammable liquids employed today, the resulting devices would be safer. Furthermore, among the possible ions, magnesium and calcium carry twice the charge of lithium, the current technological incumbent, so batteries based on these metal ions could also store more energy while minimizing the use of critical materials. However, these "multivalent" ions have difficulty moving through solids, which has prevented their use in practical batteries. With support from the Solid State and Materials Chemistry program in the Division of Materials Research at NSF, researchers at University of Texas at Austin and University of Illinois Chicago combine advanced computer simulations with laboratory experiments in a feedback loop to design materials that overcome this fundamental barrier. The simulations predict atomic structures and chemical compositions that should allow fast calcium or magnesium movement. The team then synthesizes the best candidates, measures their properties as electrolytes, and uses the results to refine the predictive models. Success in this work could lead to a new class of solid electrolyte batteries that combine high energy storage with safe operation. To enhance the impact of the research, the project aims to introduce undergraduates to cutting-edge scientific topics early