Short- and long-range structure correlations with ionic transport near the glass transition for lithium-ion polyacrylonitrile-based electrolytes using DMSO plasticizer

Here, we report a joint experimental and theoretical study using molecular dynamics calculations focusing on short- and long-range structure correlations with ionic transport near the glass transition for lithium-ion polyacrylonitrile-based electrolytes using DMSO as plasticizer. The presence of subtle modifications of the polymeric structural features near the glass transition (Tg) is rarely reported in the literature and could be relevant to study free volume in polymer-based electrolytes. Our in-situ small angle X-ray scattering (SAXS) analysis at different temperatures evidence an increment of free volume and partial loss of long-range coherence between polyacrylonitrile neighbor chains just above Tg in strong correlation with an Arrhenius behavior crossover observed for the ionic transport in these polyacrylonitrile-based electrolytes. Advancing the understanding of lithium-ion conductivity Arrhenius behavior for polymeric electrolytes with Tg slightly above room temperature could be of great relevance due to the overlap with the operating temperature range of lithium-ion batteries.