Vanadium–Manganese Redox Flow Battery: Study of Mn^III Disproportionation in the Presence of Other Metallic Ions

Abstract

The MnIII/MnII redox couple with a standard potential of +1.51 V versus the standard hydrogen electrode (SHE) has attracted interest for the design of V/Mn redox flow batteries (RFBs). However, MnIII disproportionation leads to a loss of capacity, an increase in pressure drop, and electrode passivation caused by the formation of MnO2 particles during battery cycling. In this work, the influence of TiIV or/and VV on MnIII stability in acidic conditions is studied by formulating four different electrolytes in equimolar ratios (Mn, Mn/Ti, Mn/V, Mn/V/Ti). Voltammetry studies have revealed an ECi process for MnII oxidation responsible for the electrode passivation. SEM and XPS analysis demonstrate that the nature and morphology of the passivating oxides layer depend strongly on the electrolyte composition. Spectroelectrochemistry highlights the stabilization effect of TiIV and VV on MnIII. At a comparable pH, the amount of MnIII loss through disproportionation is decreased by a factor of 2.5 in the presence of TiIV or/and VV. Therefore, VV is an efficient substitute for TiIV to stabilize the MnIII electrolyte for RFB applications.

Investigations on New Electrolyte Composition and Modified Membrane for High Voltage Zinc−Manganese Hybrid Redox Flow Batteries

“…It corresponds to the oxidation of Mn 2+ to MnO 2 with an intermediate of Mn 3+ . While at the reverse scan two cathodic peaks were observed at 1.16 and 0.82 V which is due to MnO 2 to Mn 2+ conversions [37–39] . During the reaction progress, MnO 2 is formed which then subsequently converted into Mn 2+ the mechanism behind is a simple disproportionation reaction of Mn 3+ in an aqueous solution which is described as follows [Eq.…”

Recent Progress in High‐voltage Aqueous Zinc‐based Hybrid Redox Flow Batteries

“…[48][49][50][51][52] Some aqueous RFB systems (V/Mn, polysulfide/bromine, and Zn/Br) of relatively high cell voltage (1.5 to 1.76 V) have also been reported, however, the cycle stability was hampered by Mn 3 + disproportionation, bromine crossover, and the zinc dendritic growth, respectively. [53][54][55][56][57][58][59] In this respect, the organic RFBs electrochemically stable at high potential based on the wide ESW of organic solvents have attracted much attention. Therefore, we introduced the recent non-aqueous organic RFBs (NAORFBs) research with long cycles and high cell voltage, in this section.…”

“…For example, the side reactions such as HER and OER that occurred in aqueous media have limited the voltage (1.02 to 1.30 V) of conventional aqueous RFBs (VRFBs, Fe/V, All‐iron, Fe/Cr, Zn/I, and so on) [48–52] . Some aqueous RFB systems (V/Mn, polysulfide/bromine, and Zn/Br) of relatively high cell voltage (1.5 to 1.76 V) have also been reported, however, the cycle stability was hampered by Mn 3+ disproportionation, bromine crossover, and the zinc dendritic growth, respectively [53–59] . In this respect, the organic RFBs electrochemically stable at high potential based on the wide ESW of organic solvents have attracted much attention.…”

Aqueous titanium redox flow batteries—State-of-the-art and future potential

“…Unfortunately, the addition of TiOSO 4 with MnSO 4 also reduces the cell voltage by more than 100 mV and increases the cost of energy components (Kaku et al, 2016). An alternate approach using V 5+ ions to stabilize the Mn electrolyte has also been proposed (Reynard et al, 2020). These V/Ti/Mn RFB systems will exhibit higher voltages compared to the Ti/Mn system given the lower standard electrode potential of the V 3+ /V 2+ couple (-0.26V vs SHE).…”

“…Amongst various energy storage technologies redox flow batteries (RFBs) are an economical solution at scale due to their characteristic decoupling of energy and power that ensures sublinear scaling of cost (Chen et al, 2009;Zhao et al, 2015). A plethora of possible RFBs have been investigated and proposed in the literature, such as, Fe-X (X = Cr, Mn, Fe, Zn) (Fedkiw and Watts, 1984;Skyllas-Kazacos et al, 2011;Gong et al, 2016;Selverston et al, 2017;Archana et al, 2020;Zhen et al, 2020), V-X (X = Mn, Ce, Br, V) (Chen et al, 2009;Prifti et al, 2012;Cunha et al, 2015;Zhao et al, 2015;Sankarasubramanian et al, 2019;Reynard et al, 2020;Raja et al, 2021;Wang et al, 2021) and Zn-X (X = Ce, Br, Mn, V) (Chen et al, 2009;Leung et al, 2011;Dewage et al, 2015;Zhao et al, 2015;Jiang et al, 2018;Ulaganathan et al, 2019;Naresh et al, 2021) RFBs. Critically, the translation of these RFBs to the market hinges on numerous factors, namely -1) cell potential, 2) energy density (a function of salt solubility in the electrolyte), 3) chemical and electrochemical stability of the cell components, and finally (and possibly most importantly) 4) availability of the redox active species at low marginal cost and at scale.…”