Structural Battery Electrolytes Based on a Cross-Linked Methacrylate Polymer and a Protic Ionic Liquid: Is There an Optimal Composition?
Journal article, 2025

Within the development of structural batteries, finding the optimal electrolyte composition, that is, one that offers both high ionic conductivity and mechanical stiffness, is essential. Structural batteries are multifunctional composites able to store electrical energy within load-bearing elements of devices. Their use results in a significant mass reduction, thereby improving fuel efficiency and enabling a shift to sustainable energy. In this work, structural battery electrolytes consisting of a methacrylate-based polymer, 1-ethylimidazolium bis(trifluoromethylsulfonyl)imide protic ionic liquid, and a lithium salt are investigated. Interestingly, the transport properties of the confined liquid electrolyte seem primarily limited by the percolation of the polymer network. Furthermore, upon confinement, a decrease in the glass transition temperature of the polymer phase and weaker intermolecular interactions are observed, which correlate to faster local dynamics. The self-diffusivity of the Li ions keeps high with respect to the other diffusing ions and tends to decouple from the anions upon increased temperature. The composite sample with 50 wt% of liquid electrolyte shows an ionic conductivity of approximate to 0.1 mS cm(-1) with a shear storage modulus of approximate to 150 MPa and was thus selected for proof-of-concept tests by electrochemical methods. Overall, this comprehensive study highlights the versatility of these biphasic systems for various applications.

energy materials

mechanical properties

transport properties

cross-linked polymers

protic ionic liquids

Li ion

thermal properties

Author

Nicole Abdou

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Achilleas Pipertzis

Nano and Biophysics DP

Richa Chaudhary

Chalmers, Industrial and Materials Science, Material and Computational Mechanics

Lars Evenäs

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Johanna Xu

Chalmers, Industrial and Materials Science, Material and Computational Mechanics

Leif Asp

Chalmers, Industrial and Materials Science, Material and Computational Mechanics

Jan Swenson

Chalmers, Physics, Nano and Biophysics

Anna Martinelli

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

ADVANCED ENERGY AND SUSTAINABILITY RESEARCH

2699-9412 (ISSN)

2500013

Smart Density. A web-application to compare density trade-offs

Formas (2019-00226), 2019-11-01 -- 2021-04-30.

Subject Categories (SSIF 2025)

Materials Chemistry

Condensed Matter Physics

Physical Chemistry

Areas of Advance

Materials Science

DOI

10.1002/aesr.202500013

More information

Latest update

3/25/2025