The development of a viable solid electrolyte would transform energy storage by enabling batteries with higher energy densities and safer operation. Developing such an electrolyte remains a challenge, however, as the candidate material must satisfy several requirements simultaneously: it must exhibit sufficient mechanical properties to suppress dendrite initiation on the negative electrode; it must display high ionic conductivity, with limited electronic transport; it should have a large electrochemical window, enabling its use with high voltage positive electrodes; it must be stable in contact with both electrodes; finally, it should be easy to manufacture. This talk will describe atomic scale simulations aimed at understanding several of these phenomena in the solid electrolyte, LLZO. After discussing the elastic properties of LLZO, emphasis will be given the electrochemical window and impact of surface contamination on transport. Finally, the role of solid electrolytes in minimizing crossover of species from the cathode will be described.