Abstract
From dictating the redox potential of electrolyte solvents to shaping the stability of solid-electrolyte interfaces, solvation plays a critical role in the electrochemistry of electrolytes. To efficiently design functional electrolytes for lithium batteries, it is particularly important to understand the relative solvating ability of each individual organic solvent, because most of the electrolyte systems are comprised of two or more electrolyte solvents. Using a newly developed internally referenced diffusion-ordered spectroscopy technique and diffusion coefficient-coordination ratio (D-α) analysis, we successfully constructed a solvating power series for common electrolyte solvents. We demonstrated the usefulness of this solvating power series in designing more reliable electrolyte system by selecting an appropriate fluorinated electrolyte solvent for a high-voltage lithium metal battery (LMB) as an example. For a methyl(2,2,2-trifluoroethyl)carbonate-based electrolyte, we identified fluoroethylene carbonate as a more desirable cyclic carbonate co-solvent than difluoroethylene carbonate for LMB due to its significantly higher ability to solvate lithium ions.
| Original language | English |
|---|---|
| Pages (from-to) | 1249-1254 |
| Number of pages | 6 |
| Journal | Energy and Environmental Science |
| Volume | 12 |
| Issue number | 4 |
| DOIs | |
| State | Published - Apr 2019 |
Funding
The authors gratefully acknowledge support from the U.S. Department of Energy (DOE), Vehicle Technologies Office (VTO). Argonne National Laboratory is operated by DOE Office of Science by UChicago Argonne, LLC, under contract number DE-AC02-06CH11357. The NMC electrodes were manufactured at the DOE’s CAMP Facility, at Argonne National Laboratory. The CAMP Facility is fully supported by the DOE VTO within the core funding of the Applied Battery Research for Transportation Program. The authors also thank K. Pupek and G. Krumdick from Argonne’s Materials Engineering Research Facility for providing TFPC and FEMC. We also acknowledge the computing time allotted by LCRC Argonne cluster.