| ¹³C ssNMR | The carbonyl carbon resonates at 157.6 ppm and the ether moiety at 68.0 ppm |
|---|
James M. Stevenson, Garvit Agarwal, Sibali Debnath, Zachary K. Goldsmith, Monosij Mondal, Asya Svirinovsky-Arbeli, Inwon Yeu, Amy S. Metlay, Yongbeom Kwon, Lakshmi Bhai, Rishabh D. Guha, Eric G. Keeler, John L. Weber, Daniel Steingart, Lauren Marbella, Alexander Urban, Leif D. Jacobson, Mathew David Halls, Richard A. Friesner. “Evidence for significant multi-Li+ clustering in common lithium-ion battery electrolytes.” ChemRxiv (). https://doi.org/10.26434/chemrxiv-2025-ndqzk/v4
| ¹H solution NMR (313 K, 9.4 T) | δ 4.18 ppm |
|---|---|
| ¹⁹F solution NMR (313 K, 9.4 T) | δ −74.65, −85.28, −156.0, −191.1 ppm |
| ⁷Li solution NMR (313 K, 9.4 T) | δ −1.09 ppm |
| ¹⁷O solution NMR (313 K, 9.4 T) | δ 211.3 ppm (carbonyl oxygen), 111.1 ppm (ethereal oxygen) |
| PFG NMR self-diffusion coefficients (313 K) | DEC (¹H PFG) 5.2 × 10⁻¹⁰ m²/s, DLi+ (⁷Li PFG) 2.4 × 10⁻¹⁰ m²/s, DPF6− (¹⁹F PFG) 4.5 × 10⁻¹⁰ m²/s |
| ⁷Li longitudinal relaxation (T1) | T1 = 10 ± 2 s; T1,1 = 31 ± 4 s; T1,2 = 0.9 ± 0.1 s |
| ¹³C ssNMR, uncoordinated C=O | δ 158.0 ppm; FWHM 80 Hz |
| ¹³C ssNMR, Li-coordinated C=O | δ 159.8 ppm; FWHM 482 Hz |
| ¹³C ssNMR, uncoordinated C−O | δ 68.5 ppm; FWHM 80 Hz |
| ¹³C ssNMR, Li-coordinated C−O | δ 67.3 ppm; FWHM 390 Hz |
| Density (313 K) | 1.40 ± 0.01 g/cm³ |
| Kinematic viscosity, experiment (313 K) | 2.19 ± 0.03 cSt |
| Dynamic viscosity, experiment (313 K) | 3.05 ± 0.04 mPa·s |
| Raman shifts (680–800 cm⁻¹, 313 K) | 717.34 cm⁻¹ (uncoordinated EC), 727.95 cm⁻¹ (coordinated EC), 742.26 cm⁻¹ (νP–F) |
| Raman shifts (850–950 cm⁻¹, 313 K) | 893.8 cm⁻¹ (uncoordinated EC), 903.3 cm⁻¹ (EC coordinated to Li+) |
| Raman-derived average number of EC molecules coordinated to each Li+ (N) | 3.90 |
| Raman-derived fraction of total EC coordinated to Li+ (xcoord) | 0.129 |
| ¹H solution NMR (313 K, 9.4 T) | δ 4.17 ppm |
|---|---|
| ¹⁹F solution NMR (313 K, 9.4 T) | δ −74.75, −74.36, −156.7, −191.0 ppm |
| ⁷Li solution NMR (313 K, 9.4 T) | δ −1.12 ppm |
| ¹⁷O solution NMR (313 K, 9.4 T) | δ 206.8 ppm (carbonyl oxygen), 112.3 ppm (ethereal oxygen) |
| PFG NMR self-diffusion coefficients (313 K) | DEC (¹H PFG) 3.5 × 10⁻¹⁰ m²/s, DLi+ (⁷Li PFG) 1.6 × 10⁻¹⁰ m²/s, DPF6− (¹⁹F PFG) 2.9 × 10⁻¹⁰ m²/s |
| ¹H T1 relaxation time | 42.2 s |
| ⁷Li longitudinal relaxation (T1) | T1 = 19 ± 2 s; T1,1 = 30 ± 2 s; T1,2 = 1 ± 0.2 s |
| ¹³C ssNMR, uncoordinated C=O | δ 157.8 ppm; FWHM 144 Hz |
| ¹³C ssNMR, Li-coordinated C=O | δ 160.0 ppm; FWHM 300 Hz |
| ¹³C ssNMR, uncoordinated C−O | δ 68.3 ppm; FWHM 80 Hz |
| ¹³C ssNMR, Li-coordinated C−O | δ 67.5 ppm; FWHM 400 Hz |
| Density (313 K) | 1.43 ± 0.01 g/cm³ |
| Kinematic viscosity, experiment (313 K) | 3.91 ± 0.03 cSt |
| Dynamic viscosity, experiment (313 K) | 5.60 ± 0.06 mPa·s |
| Raman shifts (680–800 cm⁻¹, 313 K) | 717.75 cm⁻¹ (uncoordinated EC), 729.24 cm⁻¹ (coordinated EC), 742.57 cm⁻¹ (νP–F) |
| Raman shifts (850–950 cm⁻¹, 313 K) | 893.8 cm⁻¹ (uncoordinated EC), 903.4 cm⁻¹ (EC coordinated to Li+) |
| Raman-derived average number of EC molecules coordinated to each Li+ (N) | 3.40 |
| Raman-derived fraction of total EC coordinated to Li+ (xcoord) | 0.288 |
| ¹H solution NMR (313 K, 9.4 T) | δ 4.15 ppm |
|---|---|
| ¹⁹F solution NMR (313 K, 9.4 T) | δ −74.92, −74.42, −157.4, −190.6 ppm |
| ⁷Li solution NMR (313 K, 9.4 T) | δ −1.18 ppm |
| ¹⁷O solution NMR (313 K, 9.4 T) | δ 202.8 ppm (carbonyl oxygen), 113.5 ppm (ethereal oxygen) |
| PFG NMR self-diffusion coefficients (313 K) | DEC (¹H PFG) 1.8 × 10⁻¹⁰ m²/s, DLi+ (⁷Li PFG) 0.81 × 10⁻¹⁰ m²/s, DPF6− (¹⁹F PFG) 1.3 × 10⁻¹⁰ m²/s |
| ¹H T1 relaxation time | 6.3 s |
| ⁷Li longitudinal relaxation (T1) | T1 = 43 ± 4 s; T1,1 = 59 ± 2 s; T1,2 = 7 ± 1 s |
| ⁶Li direct-polarization ssNMR (900 MHz ¹H frequency, 132 MHz ⁶Li frequency, 20 kHz MAS, 210 K) | δ –0.892 and –0.990 ppm with a separation of 14 Hz |
| 2D ⁶Li–⁶Li RFDR NMR (900 MHz, 10 kHz MAS, 210 K, 5 ms mixing time, 5 s recycle delay, 256 scans) | A strong diagonal peak and no resolvable cross-peaks |
| ¹³C ssNMR, uncoordinated C=O | δ 157.7 ppm; FWHM 280 Hz |
| ¹³C ssNMR, Li-coordinated C=O | δ 160.0 ppm; FWHM 325 Hz |
| ¹³C ssNMR, uncoordinated C−O | ¹³C shift N/A—single peak; FWHM – |
| ¹³C ssNMR, Li-coordinated C−O | δ 66.6 ppm; FWHM 390 Hz |
| Density (313 K) | 1.45 ± 0.01 g/cm³ |
| Kinematic viscosity, experiment (313 K) | 7.35 ± 0.09 cSt |
| Dynamic viscosity, experiment (313 K) | 10.66 ± 0.14 mPa·s |
| Raman shifts (680–800 cm⁻¹, 313 K) | 717.45 cm⁻¹ (uncoordinated EC), 729.20 cm⁻¹ (coordinated EC), 742.25 cm⁻¹ (νP–F) |
| Raman shifts (850–950 cm⁻¹, 313 K) | 894.1 cm⁻¹ (uncoordinated EC), 904.0 cm⁻¹ (EC coordinated to Li+) |
| Raman-derived average number of EC molecules coordinated to each Li+ (N) | 2.66 |
| Raman-derived fraction of total EC coordinated to Li+ (xcoord) | 0.408 |
| ¹H, ¹⁹F, ⁷Li, and ¹⁷O solution NMR (313 K, 9.4 T) | Single resonances for cations, solvents, and anions in distinct environments were not detectable in the fast-exchange regime |
|---|---|
| ¹H and ⁷Li solution NMR (313 K, 9.4 T), 2.0 M compared with 0.5 and 1.2 M | The 2.0 M linewidth was broader |
| ¹⁹F solution NMR (313 K, 9.4 T) | PF6− was the major component; minor impurities were assigned to PO2F2− near −85 ppm and F− anions near −157 and −191 ppm |
| ¹H→⁶Li CPMAS (900 MHz, 20 kHz MAS, 210 K) | The 0.5 and 1.2 M spectra were symmetric with respect to the baseline, whereas the 2.0 M spectrum exhibited pronounced asymmetry |
| Raman νP–F band against concentration | No clear trend in position |
| Raman, approximately 750–770 cm⁻¹ | No peaks were observed |
| ⁶Li direct-polarization ssNMR (900 MHz, 20 kHz MAS, 210 K) | FWHM = 17 Hz |
|---|---|
| ¹H→⁶Li CPMAS (900 MHz, 20 kHz MAS, 210 K) | No ⁶Li signal |