Dresden 2017 – wissenschaftliches Programm
CPP 51.2: Poster
Mittwoch, 22. März 2017, 18:30–21:00, P3
In situ SANS investigation of block copolymer electrolyte under lithium stripping/platting cycling — •Bernhard Springer1, Ezzeldin Metwalli1, Robert Cubitt2, and Peter Müller-Buschbaum1 — 1TU München, Physik Department, LS Funktionelle Materialien, James-Franck-Str. 1, 85478 Garching — 2ILL, 6 rue Jules Horowitz, 38042 Grenoble, France
Due to safety concerns, solid-state electrolytes have recently garnered a great interest to replace liquid electrolytes. The conductivity and morphology of the solid-state lithium-salt containing polystyrene-block-polyethylene oxide (dPS-b-PEO) diblock copolymer (DBC) electrolyte are investigated during lithium metal stripping/platting cycling at different temperatures. The in situ small angle neutron scattering (SANS) measurements were performed on electrolytes, which are sandwiched between two thin lithium electrodes. Cylindrical morphology with interpenetrated nano-domains of both, the PS and PEO/Li-ion is observed. During cycling, the morphology of the system showed nearly no changes for temperatures up to 35°C, indicating good intrinsic stability. At higher temperatures > 50°C, a slight change in the inter-domain spacing indicates only a slight change in morphology. Interestingly, the level of domain alignment is significantly enhanced. The possible migration of the lithium ions during the galvanostatic cycling seems to open pathways between the two electrodes so that at high enough temperatures the domain re-orientation is favored. Our results imply that possible dendrite formation is highly suppressed for the employed solid-state electrolyte.