The phase behavior and ionic conductivity of tetraethylammonium bis(trifl uoromethane-sulfonyl)imide (Et 4 NTFSI) salt mixtures with LiTFSI have been examined. In addition, the phase behavior and crystal structure of neat LiTFSI is also reported. Two (1- x ) Et 4 NTFSI-( x ) LiTFSI ( x = 0.50 and 0.67, where x is the mol fraction) mixed-salt crystalline phases form. Large variations in ionic conductivity are observed; these are attributed to solidsolid phase transitions of the neat Et 4 NTFSI salt creating disordered plastic crystalline phases and the formation of a low-melting eutectic composition between the neat Et 4 NTFSI salt and the 1/1 Et 4 NTFSI/LiTFSI ( x = 0.50) phase. Although Et 4 NTFSI and LiTFSI melt at 102 and 234 ° C, respectively, the two salts form a eutectic system with a melting temperature of 32 ° C. Based upon the fi ndings reported, a new conductivity mechanism is proposed for plastic crystalline salt-lithium salt electrolytes which is not ascribed to solid-state diffusion/conduction. © 2012 WILEY-VCH Verlag GmbH & Co.
All Science Journal Classification (ASJC) codes
- Renewable Energy, Sustainability and the Environment
- Materials Science(all)
Henderson, W. A., Seo, D. M., Zhou, Q., Boyle, P. D., Shin, J-H., De Long, H. C., Trulove, P. C., & Passerini, S. (2012). An alternative ionic conductivity mechanism for plastic crystalline salt-lithium salt electrolyte mixtures. Advanced Energy Materials, 2(11), 1343 - 1350. https://doi.org/10.1002/aenm.201200130