We employ atomistic molecular dynamics simulations utilizing polarizable force fields to study ion correlated motion and transport mechanisms of Li⁺ in several electrolytes and solid electrolyte interphases (SEIs). Specifically, we investigate ion-ion correlated motion and the influence of these correlations on the overall conductivity as well as Li⁺ transport and transference numbers. We demonstrate that depending on interaction with surrounding matrix, the Li⁺/anion correlated motion can provide either positive or negative contribution to the overall ionic conductivity and substantially influence the transference number. We will compare Li⁺ transport in conventional carbonate-based electrolytes (EC/LiPF₆, DMC/LiPF₆, and EC:DMC/LiPF₆), tetraglyme/LiTFSI, and bulk solid electrolyte interphases comprised of alkyl carbonate oligomers (Li₂EDC, Li₂BDC, Li₂PDC, Li₂CO₃, etc.).