PDF Publication Title:
Text from PDF Page: 199
Chapter 6: EIS and low temperature studies Figure 6-3. Nyquist plots of Li/S cell: comparison of experimentally measured data (in black) with the calculated one (in red). Firstly, the S8||S8 response is mainly dominated by a blocking behavior, which gives the low frequency contribution in the complete Li/S cell. It exhibits a very small semicircle (~ 2 Ω) at quite high frequencies, i.e. at the characteristic frequency of ~ 9 kHz, instead of 600 Hz in the complete cell. This loop was previously interpreted (chapters 2 and 3) as characteristics of the electron transport in the electronic pathway in the positive electrode. In any cases, the contribution of the positive electrode resistance to the MF loop of complete Li/S cell is very small, and cannot be distinguished in the overall response. On the contrary, we can note that the characteristic frequency of the semicircle in a complete cell (Li/S) and symmetric Li||Li cell are almost identical, and their amplitudes are very similar (in the range of ~ 100 Ω). Therefore, the loop in the MF range (of Li/S cell) can be attributed to the lithium negative electrode, with a main contribution coming from the passivation layer on the lithium surface225,248. Once could also notice the presence of a semicircle in the LF region for the symmetric Li||Li cell (Figure 6-2b, red curve). The literature often attributes this LF semicircle to the charge transfer occurring on the negative electrode225,248. In our case however, we cannot really correlate it with the charge transfer and corresponding double layer capacitance. We roughly estimated the capacitance of this semicircle according to equation (23): < ∙ T ∙ U = 1 (21) < ∙ V ∙ UW = 1 (22) (23) If considering α ~ 0.575 and R ~ 160 Ω (obtained from LF semicircle fitting), a capacitance value of ~ 1·10-3 F cm-2 was found. Assuming that for a charge transfer resistance process, a 195 Resistor in parallel with pure Capacitor (C) relation: Resistor in parallel with a Constant Phase Element (CPE) relation: T=<(WMLM) ∙VWMPDF 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 |