Towards Safer and More Sustainable PVDF-Based Ionogels for Electrochemical Energy Storage

The development of safer and more sustainable polymer electrolytes is a key challenge for next-generation electrochemical energy storage technologies. In this work, polymer ionogels based on poly(vinylidene fluoride) (PVDF) and the ionic liquid 1-Butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide were synthesized and characterized as potential semi-solid electrolytes for energy storage applications. Particular emphasis was placed on improving the sustainability and safety of the preparation process by replacing N,N-dimethylformamide (DMF), a solvent commonly employed in PVDF-based ionogel processing and associated with significant health and environmental concerns, with dimethyl sulfoxide (DMSO), which presents a more favourable safety and toxicity profile.

The resulting ionogels were comprehensively characterized by electrochemical impedance spectroscopy (EIS) to determine their ionic conductivity, rheological measurements to assess their viscoelastic and mechanical behaviour, and scanning electron microscopy (SEM) to investigate their morphology and structural homogeneity.

PVDF-based ionogels exhibited high ionic conductivity, predominantly elastic behaviour, and homogeneous microstructures, demonstrating a suitable balance between ion transport and mechanical stability for their potential use as polymer electrolytes.

These findings highlight the feasibility of using DMSO as a promising alternative to DMF in the fabrication of PVDF-based ionogels, contributing to the development of greener processing strategies without compromising the functional properties required for electrochemical energy storage applications.