Lamellar ionenes with highly dissociative, anionic channels provide low barriers for cation transport

16 May 2023, Version 1
This content is a preprint and has not undergone peer review at the time of posting.


Solid polymer electrolytes have the potential to enable safer and more energy dense batteries; however, a deeper understanding of their ion conduction mechanisms, and how they can be optimized by rational molecular design, is needed to realize this goal. Here, we investigate the impact of anion dissociation energy on ion conduction in solid polymer electrolytes via a novel class of ionenes prepared using acyclic diene metathesis polymerization of highly dissociative, liquid crystalline fluorinated aryl sulfonimide-tagged ("FAST”) anion monomers. These polyanions with various cations (Li+, Na+, K+, and Cs+) form well-ordered lamellae that are thermally stable up to 180 °C and feature domain spacings that correlate with cation size, providing channels lined with dissociative FAST anions. Electrochemical impedance spectroscopy (EIS) and differential scanning calorimetry (DSC) experiments, along with nudged elastic band (NEB) calculations, suggest that cation motion in these materials operates via an ion hopping mechanism. Moreover, the activation energy for Li+ conduction is 59 kJ/mol, which is amongst the lowest for systems that are proposed to operate via an ion conduction mechanism that is decoupled from polymer segmental motion. Furthermore, the addition of a 1 equivalent of a cation-coordinating solvent to these materials led to a >1000-fold increase in ionic conductivity without detectable disruption of the lamellar structure, suggesting selective solvation of the lamellar ion channels. This work demonstrates a novel molecular design strategy to facilitate controlled formation of dissociative anionic channels, which translates to significant enhancements in ion conduction in solid polymer electrolytes.


polymer electrolytes
fluorinated salts
decoupled ion conduction
ion hopping

Supplementary materials

Supplemental Information
Synthetic methods, experimental and computational details, spectral data, supplemental references


Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.