Details

Autor(en) / Beteiligte

• Chintapalli, Mahati
• Chen, X. Chelsea
• Thelen, Jacob L
• Teran, Alexander A
• Wang, Xin
• Garetz, Bruce A
• Balsara, Nitash P

Titel

Effect of Grain Size on the Ionic Conductivity of a Block Copolymer Electrolyte

Ist Teil von

• Macromolecules, 2014-08, Vol.47 (15), p.5424-5431

Ort / Verlag

Washington, DC: American Chemical Society

Erscheinungsjahr

2014

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• A systematic study of the dependence of ionic conductivity on the grain size of a lamellar block copolymer electrolyte was performed. A freeze-dried mixture of poly(styrene)-block-poly(ethylene oxide) and lithium bis(trifluoromethylsulfonyl)imide salt was heated in steps from 29 to 116 °C and then cooled back to 29 °C with an annealing time ranging from 30 to 60 min at each temperature. Grain structure and ionic conductivity during these steps were quantified by in situ small-angle X-ray scattering and ac impedance spectroscopy, respectively. Conductivity depends both on grain structure and temperature. A normalization scheme to decouple the dependence of conductivity on temperature and grain structure is described. Ionic conductivity at a given temperature was found to decrease by a factor of 5.2 ± 0.9 as the SAXS measure of grain size increased from 13 to 88 nm. The fact that in the system studied, large, well-formed lamellar grains are less conducting than poorly defined, small grains suggests a new approach for optimizing the transport properties of block copolymer electrolytes. Further work is necessary to confirm the generality of this finding.