PDF Publication Title:
Text from PDF Page: 016
tive electrode. To further enhance energy density, the solubility of the polyalkoxovana- Energies 2021, 14, 5643 date may be increased by replacing several surface alkoxy groups with ethers. Clusters with mixed ether/alkoxy group surface functionalization displayed improved solubility (up to 1.2 M in 0.1 M [TBA][PF6] in ACN). While the increased solubility in organic solvent and multi-electron redox chemistry is promising for enhanced energy density, prelimi- nary testing of the functionalized polyoxovanadate clusters in a RFB showed steady ca- pacity fade. The authors reported that cyclic voltammetry of electrolytes following 30 cy- cles in a RFB lead to partial degradation of the polyoxovanadate clusters [129]. Nevertheless, POMs also show the advantage that, when coupled with organic cations, they can be used in NA-RFBs [129,130] and thus overcome the barrier of the maximum ons, they can be used in NA-RFBs [130,131] and thus overcome the barrier of the maxi- mum voltage window of the current aqueous system, enabling the increase of the energy voltage window of the current aqueous system, enabling the increase of the energy density of RFBs [131–133]. density of RFBs [132–134]. 16 of 45 Nevertheless, POMs also show the advantage that, when coupled with organic cati- Regarding kinetics of these types of materials, this is influenced by the POMs’ large Regarding kinetics of these types of materials, this is influenced by the POMs’ large size and by their reduced interaction between the redox centers and the molecules of sol- size and by their reduced interaction between the redox centers and the molecules of solvent. The outer-sphere reorganization energy of the electron leads to a reduced interaction, which vent. The outer-sphere reorganization energy of the electron leads to a reduced interac- in turn leads to a low electron transfer energy and therefore high power density. Moreover, tion, which in turn leads to a low electron transfer energy and therefore high power den- the reorganization energy of the inner sphere is low due to the extra electrons that are sity. Moreover, the reorganization energy of the inner sphere is low due to the extra elec- frequently delocalized. This causes a minimal variation in coordination upon reduction trons that are frequently delocalized. This causes a minimal variation in coordination or oxidation [134]. upon reduction or oxidation [135]. Based on their versatility and properties, POMs have been studied for application Based on their versatility and properties, POMs have been studied for application in in RFBs. To highlight the operation of an aqueous POM-based RFB, the tungsten–cobalt RFBs. To highlight the operation of an aqueous POM-based RFB, the tungsten–cobalt sym- symmetric redox flow battery, H [CoW O 6 1240 ], developed by Liu at al., will be used in metric redox flow battery, H6[CoW12O40], developed by Liu at al., will be used in Figure 5 Figure 5 [135]. [136]. Figure 5. The working principle of the all-H6[CoW12O40] RFB, the structure of [CoW12O40]n- (ball-an−d- Figure 5. The working principle of the all-H6[CoW12O40] RFB, the structure of [CoW12O40] stick notation) [136]. Copyright 2017, John Wiley and Sons. (ball-and-stick notation) [135]. Copyright 2017, John Wiley and Sons. During the charging (or discharging) process, Co is reversibly oxidized (or reduced) During the charging (or discharging) process, Co is reversibly oxidized (or reduced) on tthe posiittiive siide,, tthe anode ((or cathode);; on tthe negative siide,, the cathode (or anode),, Wiissrreeducceed((orroxxiidiizzeed)).. POM-based RFBs can bessubdiiviidediinttossyymmeettrriiccoorrnnoonn-s-syymmeettrriicc,,ddeeppeenndiing whettheerrttheessameelleccttrroolylytteeiissusseedorrnottonttheposiittiiveandnegattiivesiide,,andaqueouss or non--aqueous ((ii..e..,, organiic)).. Tablle4ssummarriizestthemossttrreecceenttaapplliiccaattiionssoffPOMss iin RFBs regardiing parameters such as active species, energy density,, coullombiic efffificiiency ((CE)),,enerrgyeefffificcieiennccyy((EEE)),,ccuurrreennttddeennssitiyty, ,aannddppoowweerrddenensistiyt.y. Table 4. Parameters of POM-based RFBs reported since 2013. CellArea E CE EE j P Year 2013 2014 2017 Table 4. Parameters of POM-based RFBs reported since 2013. Active Species [SiV3W9O40]10− [PV3W9O40]9− cis-V2W4O194− (SiFe3 W9 (OH)3 O34 )2 (OH)3 14− [CoW12 O40 ]6− Li3PMo12O40 (cm2 ) (WhL−1 ) 4.8 × 10−3 3.6 × 10−3 NR 15.4 NR (%) (%) (mAcm−2 ) 2 5.0 × 10−1 NR 25–100 NR (mWcm−2 ) 1.2 3.0 × 10−1 NR 27.5 NR Ref. [136] [137] [138] [138] [135] [139] 5 5 4.63 5 4 4.63 95 <50 <95 <50 45 16 83 <50 >98 86 68 40PDF Image | PNNL Vanadium Redox Flow Battery Stack
PDF Search Title:
PNNL Vanadium Redox Flow Battery StackOriginal File Name Searched:
energies-14-05643-v2.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)