To analyse the mechanistic details of ion transport, we perform a site-projection analysis . This involves projecting the positions of Li + ions at each simulation step onto discrete bounded volumes, which correspond to "sites" within the host structure. We define two Li sites using a Voronoi decomposition of the simulation volume, with the crystallographic Li(1) and Li(2) positions used as seeds for the Voronoi cells. By projecting instantaneous Li + positions onto these Voronoi cells, we can identify and count sites that are vacant or doubly occupied. These sites can formally be described as vacancy or split-interstitial-type defects. We model the temperature dependence of these defect concentrations using an exponential Arrhenius-like model,