Techno-Economic Modeling and Analysis of Redox Flow Battery Systems

Abstract

Abstract:A techno-economic model was developed to investigate the influence of components on the system costs of redox flow batteries. Sensitivity analyses were carried out based on an example of a 10 kW/120 kWh vanadium redox flow battery system and the costs of the individual components were analyzed. Particular consideration was given to the influence of material costs and resistances of bipolar plates and energy storage media as well as voltages and electric currents. Based on the developed model it was possible to formulate statements about the targeted optimization of a developed non-commercial vanadium redox flow battery system and general aspects for future developments of redox flow batteries.

The Chemistry of Redox‐Flow Batteries

“…Then egative half-cell contained only ethaline and ab are copper electrode,a nd in [307][308][309][310][311][312][313][314][315][316][317][318][319][320][321][322][323][324][325][326] An RFB cell with an "ionic liquid" as the electrolyte was,h owever, first described by Noack et al in his patent. [327] An example was given of ab attery with 0.5 m VCl 3 in 2-hydroxyethylformiate without electrolyte convection. Theb attery was charged and discharged at 5mAcm À2 between 0.5 Va nd 1.65 Vo ver 9000 cycles,a nd ac apacity of 20 %w as found after 5000 cycles.…”

“…He explained the detachment of the catalyst layer and the resulting considerable decrease of battery power density by hydrogen evolution 186. To avoid this problem, a cell was developed with an intermediate compartment separated by another membrane,187 to oxidize diffusing V 2+ ions to V 3+ ions, and thus to prevent the formation of hydrogen at the Pt particles of the MEA. Although this type of galvanic cell is often called an RFB, strictly speaking, the lack of electrochemical reversibility of the cathode reactions makes it a fuel cell which “burns ions”.…”

Energy storage inspired by nature – ionic liquid iron–sulfur clusters as electrolytes for redox flow batteries

“…Therefore, ILs are highly interesting for RFB applications; 41 however only a few IL-based systems have been reported so far. 23,42,43 Additionally, in comparison with acidic and aqueous electrolytes, like the classic vanadium system, ionic liquids are not corrosive and thus allow the use of less robust materials (e.g. pump, tank, and tubing).…”

Die Chemie der Redox‐Flow‐Batterien

“…Damit begründete Palminteri das Ablösen der Katalysatorschicht und die dadurch starke Leistungsdichteabnahme der Batterie 186. Zur Vermeidung dieses Problems wurde eine Zelle mit einem durch eine weitere Membran abgetrennten Zwischenraum entwickelt,187 um in Richtung Kathode diffundierende V 2+ ‐Ionen zu V 3+ ‐Ionen zu oxidieren und damit die Wasserstoffentstehung an den Pt‐Partikeln der MEA zu verhindern. Obwohl diese Art von galvanischer Zelle oftmals als RFB bezeichnet wird, handelt es sich aufgrund der fehlenden elektrochemischen Reversibilität der Kathodenreaktionen streng genommen um eine Brennstoffzelle, die “Ionen verbrennt”.…”

“…Eine RFB‐Zelle mit einer ionischen Flüssigkeit als Elektrolyt wird jedoch erst von Noack et al. in seinem Patent beschrieben 327. Darin wird als Beispiel eine Batterie mit 0.5 M VCl 3 in 2‐Hydroxyethylformiat ohne Elektrolytkonvektion angegeben.…”