In this work, an electrolyte composed of LiTFSI salt in tetraglyme was fully characterized over a range of salt concentrations, involving the measurement of three transport parameters and a thermodynamic factor. The measurement of these parameters fully describes ion motion, which can be used to determine efficaciousness of electrolytes for use in lithium-ion batteries. This work utilizes the method developed by Balsara and Newman, which combines conductivity, restricted diffusion, polarization techniques, and concentration cells, to fully characterize the electrolyte [1,2]. These separate measurements can be used to determine the rigorously defined transference number as defined in Newman’s concentrated solution theory. Electrochemical results are compared to results from electrophoretic NMR (eNMR), a technique which directly measures ion velocities under applied electric fields. Comparisons between the electrochemical and eNMR results will be discussed at the meeting.

[1] Balsara, N. P., & Newman, J. (2015). Relationship between steady-state current in symmetric cells and transference number of electrolytes comprising univalent and multivalent ions. Journal of The Electrochemical Society, 162(14). doi:10.1149/2.0651514jes

[2], Shah, D. B., Nguyen, H. Q., Grundy, L. S., Olson, K. R., Mecham, S. J., DeSimone, J. M., & Balsara, N. P. (2019). Difference between approximate and rigorously measured transference numbers in fluorinated electrolytes. Physical Chemistry Chemical Physics, 21(15), 7857-7866. doi:10.1039/c9cp00216b