Unraveling Structure-Property Relationships in Cellulose-based Anion Conducting Polymerized Ionic Liquids

Conventional polymeric materials in electrochemical devices are typically derived from petroleum-based products, but biomass-derived materials offer extra value-added benefits in sustainability. Single-ion conducting polymer electrolytes are an emerging class of materials offering advantages such as mechanical strength, transference numbers of unity, and the potential for safer chemistries for various electrochemical devices such as batteries, fuel cells, electrolyzers, gas separation membranes, gas sensors, and carbon capture materials. This study explores the structure-property relationships of a cellulose-based anion-conducting polymerized ionic liquid (PIL) with varying counteranion: NTf2-, OTf-, PF6-, and Br-. Experimental techniques such as X-ray scattering, broadband dielectric spectroscopy, and differential scanning calorimetry are used to examine the interplay between nanoscale structure, polymer and ion dynamics, and varying anion properties. Preliminary results reveal the presence of superionic transport, i.e. a decoupling between polymer and ionic dynamics which boosts ionic conductivity, in multiple counteranion samples. These findings clarify new design rules for increasing the competitiveness of these cellulose-based PILs against their synthetic alternatives.