Non-solvating, side-chain polymer electrolytes as lithium single-ion conductors: synthesis and ion transport characterization
Jiacheng Liu, Phillip D. Pickett, Bumjun Park, Sunil Upadhyay, Sara Orski, Jennifer Schaefer
Solid-state single-ion conducting polyelectrolytes have drawn considerable interest for secondary lithium batteries due to their high ion conductivities under solvent-free conditions. Specifically, poly(ethylene oxide) (PEO) based electrolytes have the highest reported Li+ conductivities for these materials; however, their potential is limited due to the ion transport mechanism being coupled to segmental relaxations of the cation solvating polymer chain. To investigate the potential of single-ion conducting polymer electrolytes lacking polar matrices, we synthesized three para-polyphenylene-based, side-chain polymer electrolytes with various pendent anion chemistries (-SO3-, -PSI-, and -TFSI-) with differing binding affinities to Li+. Compared with the previously reported lithium poly(4- styrenesulfonyl(trifluoromethylsulfonyl)imide) (LiPSTFSI), the side-chain polymers showed at least 3 orders of magnitude higher conductivity with the same -TFSI- anion. We found that the side-chain electrolyte showed a dielectric relaxation dominated transport mechanism through use of dielectric spectroscopy analysis. The conductivity is highly dependent on the charge delocalization and size of the pendent anion, which provides a pathway forward for the engineering of polymeric ion conductors for electrochemical applications.
, Pickett, P.
, Park, B.
, Upadhyay, S.
, Orski, S.
and Schaefer, J.
Non-solvating, side-chain polymer electrolytes as lithium single-ion conductors: synthesis and ion transport characterization, Polymer Chemistry, [online], https://doi.org/10.1039/C9PY01035A
(Accessed October 16, 2021)