On the significance of sulphuric acid dissociation in the modelling of vanadium redox flow batteries

Abstract

A recent asymptotic model for the operation of a vanadium redox flow battery (VRFB) is extended to include the dissociation of sulphuric acid -a bulk chemical reaction that occurs in the battery's porous flow-through electrodes, but which is often omitted from VRFB models. Using asymptotic methods and time-dependent two-dimensional numerical simulations, we show that the charge-discharge curve for the model with the dissociation reaction is almost identical to that for the model without, even though the concentrations of the ionic species in the recirculating tanks, although not the state of charge, are considerably different in the two models. The ability of the asymptotic model to extract both the qualitative and quantitative behaviour of the considerably more time-consuming numerical simulations correctly indicates that it should be possible to add further physical phenomena to the model without incurring significant computational expense.

A computational model of a liquid e-fuel cell

“…The anode side of this liquid e-fuel cell houses the fuel as well as serves as the proton source due to the type of e-fuel solution (containing 0.5 M V 2+ and H2SO4) employed in the cell operation. The sulfuric acid (H2SO4) functions as the supporting electrolyte, which can dissociate into 𝐻𝐻 + and 𝑆𝑆𝑂𝑂 4 2− at the anode compartment [23,29]. As mentioned earlier, the operation of the e-fuel cell involves the transport of protons (𝐻𝐻 + ) from the anode through the membrane which subsequently participate in the electrochemical reactions occurring at the cathode side as given in Equation ( 2).…”

Utilization of the spent catalyst as a raw material for rechargeable battery production: The effect of leaching time, type, and concentration of organic acids

“…As previously explained, the leaching process is strongly influenced by the strength of the acid, as seen from the number of hydrogen ions in the system. Sulphuric acid in water dissociates entirely according to the following chemical reaction equation (Vynnycky & Assunção, 2020).…”

Mathematical modelling of macrosegregation in binary alloys induced by convection

“…where e air and e s are the thickness of the air layer and the slag 3 , respectively and k air and k s represent their thermal conductivities. R 0 is the nominal resistance that depends on the surface roughness, and R rad is the resistance associated with radiation heat transfer:…”