  Traditional approaches to identify ion-transport pathways often presume equal
probability of occupying all hopping sites and focus entirely on finding the
lowest migration barrier channels between them. Although this strategy has been
applied successfully to solid-state Li battery materials, which historically
have mostly been ordered frameworks, in the emerging class of disordered
electrode materials some Li-sites can be significantly more stable than others
due to a varied distribution of transition metal (TM) environments. Using
kinetic Monte Carlo simulations, we show that in such cation-disordered
compounds only a fraction of the Li-sites connected by the so-called
low-barrier ``0-TM" channels actually participate in Li-diffusion. The
Li-diffusion behavior through these sites, which are determined primarily by
the voltage applied during Li-extraction, can be captured using an effective
migration barrier larger than that of the 0-TM barrier itself. The suppressed
percolation due to cation disorder can decrease the ionic diffusion coefficient
at room temperature by over 2 orders of magnitude.

Materials Science