PDF Publication Title:
Text from PDF Page: 033
DHA formation vs state of charge of DHAQ The state of charge (SOC) limit of the DHAQ electrolyte was demonstrated to strongly influence the cycling capacity fade rate. To directly quantify the relationship between capacity fade rate and SOC limit, an aqueous electrolyte comprising 0.1 M DHAQ and 1.2 M KOH was charged in an oxygen-free glovebox to approximately 90, 80, 70, and 60% SOC (DHAHQ relative to total DHAQ + DHAHQ). Slow charging was performed potentiostatically at a minimal value of 1.25 V in order to avoid overcharging the electrolyte in proximity to the electrodes. In order to reach 90% SOC, the potential was increased to 1.3 V near the end of charge to reach the desired SOC. Within 1 hour of charging, aliquots were diluted with D2O in sealed LPV NMR tubes, and the 1H NMR spectra were obtained without exposure to oxygen. The resulting spectra (Fig. S21) depict broadening of the peaks corresponding to DHAQ, whereas those corresponding to DHA are sharp and diminishing in area as the SOC is decreased (spectrum at 60% SOC not shown due to lack of quantifiable peaks). When quantified relative to a sodium methanesulfonate internal standard (δ 2.6 ppm, not shown), the amount of DHA observed at 70% SOC is approximately 33% and 16% of the amount observed at 80% and 90% SOC, respectively. Although an exact correspondence with a cycling fade rate cannot be established due to variable charging conditions and the time dependence of DHA formation, this result demonstrates the sensitivity of DHA formation to SOC and is consistent with the proposed disproportionation reaction described in the main text. Figure S21. Relative concentration of DHA at different SOC of DHAQ. Integration of signals with chemical shift of 7.8 ppm reflect the relative quantities of DHA vs a sodium methanesulfonate internal standard (δ 2.6 ppm, not shown). 23PDF Image | Extending organic flow batteries via redox state management
PDF Search Title:
Extending organic flow batteries via redox state managementOriginal File Name Searched:
mja287.pdfDIY PDF Search: Google It | Yahoo | Bing
Salgenx Redox Flow Battery Technology: Salt water flow battery technology with low cost and great energy density that can be used for power storage and thermal storage. Let us de-risk your production using our license. Our aqueous flow battery is less cost than Tesla Megapack and available faster. Redox flow battery. No membrane needed like with Vanadium, or Bromine. Salgenx flow battery
CONTACT TEL: 608-238-6001 Email: greg@salgenx.com (Standard Web Page)