PDF Publication Title:
Text from PDF Page: 110
Section 6.5 Evaluation of all twenty-four cell designs Table 6-5: RTSE values for two different current densities and all twenty-four designs Channel design variation Area Electrode 123456 short short short long long long wide medium narrow wide medium narrow Current density 25 mAcm-2 72.9% 74.5% 76.2% 75.5% 76.6% 77.6% 74.8% 77.2% 77.8% 76.7% 78.2% 78.5% 76.8% 77.5% 78.1% 77.9% 78.3% 78.6% 77.6% 78.0% 78.4% 78.3% 78.5% 78.6% Current density 100 mAcm-2 71.8% 72.1% 72.2% 72.3% 72.4% 72.2% 72.1% 72.4% 72.3% 72.4% 72.4% 72.1% 72.3% 72.3% 72.2% 72.4% 72.3% 72.0% 72.2% 72.2% 72.0% 72.2% 72.0% 71.6% variation area 1 1000 cm2 2 2000 cm2 3 3000 cm2 4 4000 cm2 1 1000 cm2 2 2000 cm2 3 3000 cm2 4 4000 cm2 Consequentially, design 4.6 with the largest studied electrode and the largest studied channel geometry factor yields the highest RTSE. Nominal current density For cycles with nominal current density, variations in RTSE caused by different cell designs are significantly smaller. Lowest and highest RTSE are only 0.6 %-points apart. Neither the largest electrode nor the largest channel geometry factor yield the highest efficiency. For an electrode area of 1000 and 2000 cm2, the shortest and widest channel yields the lowest efficiency. Hence, the negative effect of the shunt currents is still considerable for these cells, even for the operation with the nominal current density. Current-weighted average RTSE So far, different designs yield the highest RTSE for different current densities. Hence, the efficiencies are now weighted according to the applied current density, in order to identify the cell design which offers the best performance over the whole operation range. It is an intrinsic property of the deployed rating procedure that the RTSE at nominal current density has the highest impact and the RTSE at lowest studied current density has the lowest impact, as shown in Eq. (6-1) on page 87. The variation in the current- weighted RTSE for the twenty-four designs is 1.6 %-points. The design that yields the highest current-weighted RTSE is neither the design that yields the highest RTSE for the lowest studied current density, nor the design that yields the highest RTSE for the nominal current density. Cell design 2.5 complies best with the requirement of an efficient battery operation with variable current densities. It comprises a 2000-cm2 electrode and a channel with a length of 1,129 mm, a width of 10 mm, a resulting geometry factor of 37,629 m-1, a nominal flow rate of 67.8 Lmin-1 and a nominal pressure drop across the stack of 53.2 kPa. 102PDF 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)