We also use DFT calculations to explore the electronic properties of Ag + -LLZO. The lowest energy configuration for the Ag-Li ion exchange in LLZO occurs when a Ag + replaces a Li + on the slightly larger octahedral Li + (96h) site (Figure ). The electronic partial density of states (pDoS) was compared to that of pristine LLZO. In Figure This contribution is due to the O-p and Ag-d orbitals, thus introducing defect states close to the VBM. These are isolated defect states that are locally bound to the silver. Additionally, the charge state of the silver ion is predicted to be lower than that of lithium ion, indicating Ag-O bonds are more covalent than Li-O bonds (see the charge state discussion in SI).