Title: 

Helical covalent polymers with unidirectional ion channels as single lithium-ion conducting electrolytes

Year of Publication:

2021

Authors:

Yiming Hu, Nathan Dunlap, Hai Long, Hongxuan Chen, Lacey J Wayment, Michael Ortiz, Yinghua Jin, Abdulrahiman Nijamudheen, Jose L Mendoza-Cortes, Se-hee Lee, Wei Zhang

Journal:

CCS Chemistry

Abstract:

Single-ion conducting polymer electrolytes have attracted great attention as safe alternatives to liquid electrolytes in high energy density lithium-ion batteries. Herein, we report the first example of a crystalline anionic helical polymer as a single lithium-ion conducting solid polymer electrolyte (SPE). Single-crystal X-ray analysis shows that the polymer folds into densely packed double helices, with bundles of unidirectional negatively charged channels formed that can facilitate lithium-ion transportation. Such a helical covalent polymer (HCP) exhibits excellent room temperature lithium-ion conductivity (1.2 × 10⁻³ S·cm⁻¹) in the absence of external lithium salts, a high transference number (0.84), low activation energy (0.14 eV), and a wide electrochemical stability window (0.2–5 V). We found that nonflammable, nonvolatile ionic liquid can serve as a solvating medium and excellent conductivity enhancer (>1000 times …

URL:

https://www.chinesechemsoc.org/doi/abs/10.31635/ccschem.021.202101257