Regensburg 2013 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 18: Poster: Polymer Dynamics

CPP 18.21: Poster

Tuesday, March 12, 2013, 18:15–20:15, Poster C

Li-dynamics in amorphous PEO electrolytes in supercooled liquid states — •Joyjit Chattoraj, Diddo Diddens, and Andreas Heuer — Institute of Physical Chemistry, Westfälische Wilhelm Universität Münster, Corrensstr. 28/30 , D-48149 Münster, Germany

The effect of ionic liquids on Li-dynamics is investigated via MD simulation in a poly(ethylene oxide) PEO-based polymer electrolyte material containing Li-TFSI salt and MPPY-TFSI ionic liquid (IL) for a vast temperature regime ranging from above the freezing temperature to the vicinity of the glass transition temperature of PEO. Li cations are complexed with ether oxygen atoms and move via continuous bond breaking and making. Three key mechanisms of cation transport in polymer melts had already been identified at temperatures well above the freezing point. These are M1: intrachain motion, M2: segmental motion and M3: interchain motion. In addition, a plasticizing effect of ionic liquid had been noticed by Diddens et al [arXiv:1211.3413]. In this paper we show that the three mechanisms also hold for low temperatures and a simple Rouse model could be applied to explain these mechanisms as done in the case of high temperature polymer melt. The plasticizing effect of ionic liquid diminishes as we find that the diffusion coefficient of Li tends to collapse for all IL concentrations while approaching the glass transition.