PDF Publication Title:
Text from PDF Page: 012
UnderstandininggththeeVVaannaaddiuimumRRedeodxoFxloFwlowBaBttaetrtiesries 31413 Current ηenergy ηvoltage ηcoulombic Current ηenergy ηvoltage [A] [%] [%] [%] [A] ηcoulombic [%] [%] [%] EXPERIMENTAL DATA SIMULATION RESULTS 10 97.0 20 94.1 40 88.6 60 83.3 80 78.4 100 73.7 97.0 100 94.1 100 88.6 100 83.3 100 78.4 100 73.7 100 60 100 (cycle 1) 100 (cycle 2) 100 (cycle 3) 78.3 82.8 94.6 68.0 72.3 94.0 70.8 73.0 96.1 73.1 74.0 98.7 Table 4. Efficiencies at various currents. The cycle starts at 2.5% SoC, the battery is charged until a 97.5% SoC and then discharged until a 2.5% SoC. Experimental data are from (Skyllas-Kazacos & Menictas, 1997). At the beginning of the cycle, the battery state of charge SoC is 2.5% (discharged); the battery is charged at constant current until a SoC of 97.5% and then discharged until it reached its initial SoC. The resulting stack voltages Ustack and power Pstack are illustrated in Fig. 8 and the efficiencies are summarized in Tab. 4 along with experimental data. We observe quickly that the efficiencies decrease as the current increases. 35 30 25 20 15 40 30 20 10 Charge and discharge cycle |I|=10 [A] |I|=20 [A] |I|=40 [A] |I|=60 [A] |I|=80 [A] |I|=100 [A] 0 6 12 18 24 30 36 42 time [h] Charge and discharge cycle at 40A 0 0 6 12 time [h] Fig. 8. Stack voltages during charge/discharge cycles at diverse currents. Below: stack voltage, current and power at 40A. The voltage efficiencies ηvoltage are accurately determined by the model; the difference with the experimental data always stays below 2%. The losses in coulombic efficiency ηcoulombic can be caused by side reactions or cross mixing of electrolyte through the membrane which are not taken into account in the model; note that ηcoulombic has improved as the battery becomes conditioned. When ηcoulombic is close to 100%, as it is the case for the last cycle, Ustack [V] |Istack| [A] |Pstack|/100 [W] stack voltage [V]PDF Image | Understanding the Vanadium Redox Flow Batteries
PDF Search Title:
Understanding the Vanadium Redox Flow BatteriesOriginal File Name Searched:
12523.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 | RSS | AMP |