Abstract: The development of robust and efficient solid electrolytes would transform mobile 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:

1. It must display high ionic conductivity, with limited electronic transport.
2. It must exhibit sufficient mechanical properties to suppress dendrite initiation on the negative electrode.
3. It should have a large electrochemical window, allowing its use with high voltage electrodes.
4. It must be chemically stable in contact with both electrodes.
5. It should be easy to manufacture.

This talk will describe atomic-scale simulations aimed at understanding several of these phenomena in the prototype solid electrolyte, L_i7La₃Zr₂O₁₂ (LLZO). Emphasis is given to understanding the role played by interfaces with electrodes and at internal interfaces (grain boundaries) within bulk LLZO. Several scenarios associated with the penetration of lithium ​“dendrites” through LLZO are evaluated computationally.