READ ME File For 'Dataset for Operando Characterization of Active Surface Area and Passivation Effects on Sulfur-Carbon Composites for Lithium-Sulfur Batteries'

Dataset DOI: 10.5258/SOTON/D2009

ReadMe Author: He Li, University of Southampton, North China Electric Power University

This dataset supports the publication:
AUTHORS: He Li, John Lampkin, Yu-Chuan Chien, Liam Furness, Daniel Brandell, Matthew Lacey, Nuria Garcia-Araez
TITLE: Operando Characterization of Active Surface Area and Passivation Effects on Sulfur-Carbon Composites for Lithium-Sulfur Batteries
JOURNAL: Electrochimica Acta
PAPER DOI: 10.1016/j.electacta.2021.139572


This dataset contains:


The figures are as follows:

Figure 4. Impedance response of symmetrical cells with CNT electrodes coated on a) Cu foil, b) Mo foil and c) Al foil (with enlarged figures inset). The CNT electrodes contain CNT and binder (PEO+PVP) in a mass ratio of 88:12. The red lines show the fit to d) the equivalent circuit. Impedance values are normalised by the electrode geometrical area.

Figure 5. Results of the specific surface area (SSA) of carbon in CNT and S/CNT electrodes, coated on different substrates, as indicated. The SSA values have been obtained by fitting the impedance data to the equivalent circuit in Figure 3b, but consistent values are obtained with other fitting methods (see table 1). The results of the BET specific surface areas are also shown to facilitate comparison.  The specific surface area values are normalised by the mass of carbon, and the carbon loading values are normalised by the geometrical area of the electrode.

Figure 6. a) Impedance response of Li-S cells in the fully charged state: at OCV (ca. 2.9 V) for the pristine cell (i.e., before cycling) and 2.8 V for cycled cells, at the indicated cycle numbers. The cells contain an optimised S/C electrode formulation producing high performance (see details in the experimental section). b) Fit of the low frequency impedance of the pristine cell. c,d) Fit of the low frequency impedance of a cycled cell, for cycle number 6 and 156 in c) and d).

Figure 7. a) Specific surface area (SSA) of carbon in the optimised S/C electrode formulation used in a Li-S cell (with carbon loading of 1.79 mgC cm-2), evaluated by fitting the impedance data in figure 6 to the equivalent circuits shown in the graph. b) Cycle performance of the same Li-S cell.

Figure S1. Impedance results of symmetrical cell with self-standing carbon electrodes made with acetylene black and PTFE binder, in a mass ratio of 66:34. The cell contains copper current collectors that have been polished just prior cell assembly, and thus, the natural copper oxide layer is absent and does not produce a contact resistance. The red lines show the fit to the equivalent circuit shown in the figure. Electrolyte: 1 M LiTFSI in DOL.

Figure S2. As in figure S1, but with cells in which one of the carbon electrodes has been replaced by a lithium metal electrode. The red line shows the fit of the low frequency impedance to the equivalent circuit shown in the figure.

Figure S3. As in figure S1, but with self-standing sulfur-carbon composite electrodes containing sulfur, acetylene black and PTFE binder in a mass ratio of 24:66:10. 

Figure S4. As in figure S1, but with self-standing sulfur-carbon composite electrodes containing sulfur, acetylene black and PTFE binder in a mass ratio of 70:20:10. 

Figure S5. Impedance response as in Figure 4, but with S/CNT electrodes coated on a) Mo foil and b) Al foil. The S/CNT electrodes contain S, CNT and binder (PEO+PVP) in a mass ratio of 58.8:29.4:11.8. Red lines show the fit of impedance data to the equivalent circuit c).

Figure S6. Results of fitting the impedance data of the Li-S cell in Figure 6 at low frequencies (0.631-0.002 Hz) to an equivalent circuit consisting of a resistor coupled, in series, to a combination of a CPE and a resistor in parallel.

Figure S7. a) Specific surface area (SSA) of carbon in the optimised S/C electrode formulation used in another Li-S cell (with carbon loading of 1.48 mgC cm-2). b) Cycle performance of the same Li-S cell.

Figure S8. As in figure S6 but for the Li-S cell in figure S7.

Figure S9. a) Impedance response of a symmetrical cell with optimised S/C electrodes. The line shows the fit to the equivalent circuit shown in the figure. b) Specific surface area of carbon in the S/C electrodes, as indicated. The average value is 274 ¡À 19 m2 gC-1 (confidence interval at 95% confident level).

Figure S10. Performance of Li-S cells made with the optimised S/C electrodes used in Figure 6, but with a standard cycling protocol with 1.8 and 2.6 V voltage limits at C/10.

Figure S11. Voltage profiles of Li-S cells at selected cycles, for the cells tested with the standard cycling protocol (results in figure S10) and with the protocol for impedance measurements (results in figure 7). 


Date of data collection: 08/11/2018 to 16/08/2021

Information about geographic location of data collection: Southampton, UK
Uppsala, Sweden

Licence:

Related projects: EPSRC (EP/S003053/1, Grant FIRG014), EPSRC (EP/N024303/1), STandUP for Energy consortium

Date that the file was created: November, 2021