PDF Publication Title:
Text from PDF Page: 098
(a) (b) Figure 3-18. Schematic illustration of the beneficial effects when incorporating a 3D porous NwC current collector (a) over the classical 2D Al foil (b). 3.4.7. The importance of the electrolyte amount It is clear, in regard to our previous study45,157, that electrolyte added in a large excess provides better cyclability to the Li/S cells, but a lower energy density as well. Low amount of electrolyte, on the other hand, may affect the cyclability, reduce the capacity and increase the polarization105. As a consequence, if the electrolyte amount is not sufficient, it may result in incomplete sulfur utilization already in the initial cycles. To study the performances of ‘S-on- NwC’ electrodes with reduced amounts of electrolyte, two coin cells were prepared using standard method (keeping both Viledon® and Celgard®2400 as separators), but with the lower amount of electrolyte than used as reference (150 μL), i.e. 75 μL and 50 μL. The electrodes had slightly different sulfur loadings: ~ 3.78 mgSulfur cm-2 for the ‘75 μL’ cell and ~ 4.54 mgSulfur cm-2 for the ‘50 μL’ cell. Both cells were discharged and charged at C/20 only one time (the aim was to observe the voltage profiles rather than to perform prolonged cycling). The results are shown on Figure 3-19, while the ‘150 μL’ reference cell is also presented on the graph for easier comparison. When decreasing the electrolyte amount to 75 μL, reasonably good capacity can still be obtained (~ 1000 mAh g-1), even if lower than for the cell with highest electrolyte amount (1110 mAh g-1). However, end of discharge is slightly modified while the overpotential is slightly increased as well. This may be related with the difference in terms of polysulfides concentration (thus the electrolyte viscosity). On the other hand, 50 μL is not enough to cycle the cell, which is actually an expected behavior, when keeping in mind the theoretical volume necessary to fulfill all the porosity (59 μL; see Table 3-4). 94 Chapter 3: S8 electrode on NwCPDF Image | Accumulateur Lithium Soufre
PDF Search Title:
Accumulateur Lithium SoufreOriginal File Name Searched:
WALUS_2015_archivage.pdfDIY PDF Search: Google It | Yahoo | Bing
Sulfur Deposition on Carbon Nanofibers using Supercritical CO2 Sulfur Deposition on Carbon Nanofibers using Supercritical CO2. Gamma sulfur also known as mother of pearl sulfur and nacreous sulfur... More Info
CO2 Organic Rankine Cycle Experimenter Platform The supercritical CO2 phase change system is both a heat pump and organic rankine cycle which can be used for those purposes and as a supercritical extractor for advanced subcritical and supercritical extraction technology. Uses include producing nanoparticles, precious metal CO2 extraction, lithium battery recycling, and other applications... More Info
| CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com | RSS | AMP |