In the first part of this poster presentation, we will present the solid state NMR studies of several PolyEthylene Oxide (PEO)/Li+ complex crystals. In this part, we focus on the helical jumps of PEO segment in the crystals, which were considered to initiate the Li+ transportation in the crystal.1 In addition, the influence from the crystal structure and the thickness of the crystal lamella on the jump motion were studied and discussed.2
Secondly, we will present some new findings on the PEO/Li+ complex systems prepared via the supramolecular self-assembly of PEO, cyclodextrin (alpha-CD) and LiAsF6.3 These polymer electrolytes, named as the alpha-CD-PEO/Li+ complexes, consists of the nanochannels formed by CD in which the PEO/Li+ complexes are confined. By combining 2H, 7Li and 13C NMR, we have studied the structure and dynamics of the PEO/Li+ complex in the nanochannel in great detail. The correlation between the dynamics of Li+ ions in the nanochannel and the macroscopic ion conductivity was studied and discussed. The obtained information deeps our understanding of the mechanism of ionic conductivity of the materials.
This work represents an example of the creative potential of moden solid-state NMR to elucidate the complicated structures and dynamics in the crystalline polymer electrolytes, and subsequently help to guide the research of polymer electrolytes.
References:
1. Y. Gao, B. Hu, Y. Yao, Q. Chen, Chemistry–A European Journal, 17, 8941-8946(2011).
2. L. Wei, Q. Liu, Y. Gao, Y. Yao, B. Hu, Q. Chen, Macromolecules, 46, 4447–4453(2013).
3. L. Chen, X. Zhu, D. Yan, Y. Chen, Q. Chen, Y. Yao, Angewandte Chemie, 118, 93-96(2006).