Elucidating the mechanisms of ion conductivity enhancement in polymer nanocomposite electrolytes for lithium ion batteries

Solid polymer electrolytes in lithium ion batteries offer significant advantages compared to conventional liquid electrolytes including safety, stability, and thin film manufacturability. The major disadvantage of poor ion conductivity especially at room temperature still presents a challenge. Nanoscale fillers are shown to improve ion conductivity up to 3 orders of magnitude although the specific mechanisms for enhancement are still under debate. In this study, we investigate the mechanisms of lithium ion conductivity enhancement and degradation in polymer nanocomposite electrolytes. Agreement between our model predictions and experiments confirm that our postulated mechanisms can explain the dependence of ion conductivity on nanofillers.