Abstract
Fluorine-free electrolytes have attracted great attention because of its low-cost and environmental friendliness. However, so far, little is known about the solution structures of these electrolytes. Here, we compare the solvation phenomenon of sodium tetraphenylborate (NaBPh4) salt dissolved in organic solvents of propylene carbonate (PC), 1,2-dimethoxyethane (DME), acetonitrile (ACN) and tetrahydrofuran (THF). Small-angle X-ray scattering (SAXS) reveals a unique two-peak structural feature in this salt-concentrated PC electrolyte, while solutions using other solvents only have one scattering peak. Molecular dynamics (MD) simulations further reveal that there are anion-based clusters in addition to the short-range charge ordering in the concentrated NaBPh4/PC electrolyte. Raman spectroscopy confirms the existence of considerable contact ion pairs (CIPs). This work emphasizes the importance of global and local structural analysis, which will provide valuable clues for understanding the structure-performance relationship of electrolytes.
| Original language | English |
|---|---|
| Pages (from-to) | 340-346 |
| Number of pages | 7 |
| Journal | Journal of Energy Chemistry |
| Volume | 70 |
| DOIs | |
| State | Published - Jul 2022 |
| Externally published | Yes |
Funding
This work was supported as part of the Joint Center for Energy Storage Research, an Energy Innovation Hub funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences. This research used resources of the Advanced Photon Source and Center for Nanoscale Materials, both are U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. AC02-06CH11357. We gratefully acknowledge the computing resources provided on Bebop, a high-performance computing cluster, operated by the Laboratory Computing Resource Center at Argonne National Laboratory. Kun Qian and Zhou Yu contributed equally to this work. T. Li is thankful for the supported by U.S. National Science Foundation (Grant No. 2120559). This work was supported as part of the Joint Center for Energy Storage Research, an Energy Innovation Hub funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences. This research used resources of the Advanced Photon Source and Center for Nanoscale Materials, both are U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. AC02-06CH11357. We gratefully acknowledge the computing resources provided on Bebop, a high-performance computing cluster, operated by the Laboratory Computing Resource Center at Argonne National Laboratory. Kun Qian and Zhou Yu contributed equally to this work. T. Li is thankful for the supported by U.S. National Science Foundation (Grant No. 2120559).
Keywords
- Fluorine-free electrolytes
- Small-angle X-ray scattering
- Sodium tetraphenylborate
- Sodium-ion batteries
- Solvation structures