PDF Publication Title:
Text from PDF Page: 102
Section 6.4 Comparison of two sample designs volumes differ by a factor of four. The decreasing discharge capacity can be explained by the higher stack voltage during the charging process with a high current density. Hence, the upper cell voltage limit is reached earlier and thus at a lower tank SoC, as shown in Figure 6-2 on page 90. During the discharging process, the higher current density lowers the stack voltage. Thus, the lower cell voltage limit is also reached earlier and thus at a higher SoC. A lower tank SoC at the end of the charging process and a higher tank SoC at the end of the discharging process automatically results in a lower discharge capacity. Hence, a larger current density leads to a lower discharge capacity. Regarding the flow rate, an increasing flow factor increases the discharge capacity, as long as the additionally used SoC limits of 5 % and 90 % are not reached during charging and discharging operations. A larger flow factor decreases the cell voltage during the charging process, as shown in Figure 5-2 on page 80 and thus increases the time until the upper cell voltage limit is reached. Consequently, the tank SoC at the end of the charging process is higher for a larger flow factor. During the discharging process, a larger flow factor increases the cell voltage which increases the time until the lower cell voltage limit is reached. Hence, more electric charge carriers can be released from the tank. Both, the higher tank SoC at the end of the charging process and thus at the beginning of the discharging process and the possibility to withdraw more electric charge carriers from the tank increases the discharge capacity. However, in practice, the boost of discharge capacity by a larger flow factor is limited by the pump capacity. The discharge capacity boost obtained with lower current densities is additionally limited by the deployed SoC limits. These limits are the reason why the discharge capacity for a current density of 25 mAcm-2 is almost the same as for a current density of 50 mAcm-2, as shown in Figure 6-5. Figure 6-5: Specific discharge capacity over flow factor in dependence of current density for the designs 1.1 and 4.6 Design 4.6 yields a peak discharge capacity of 21.2 WhL-1 for a current density of 25 mAcm-2 exploiting 70.8 % of the theoretical specific capacity. The theoretical 94 Specific discharge capacity in WhL-1PDF Image | Model-based Design Vanadium Redox Flow Batteries
PDF Search Title:
Model-based Design Vanadium Redox Flow BatteriesOriginal File Name Searched:
10-5445IR1000070670.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)