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

No Thumbnail Available

Access rights

openAccess
acceptedVersion

URL

Journal Title

Journal ISSN

Volume Title

A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Date

2020-06-05

Major/Subject

Mcode

Degree programme

Language

en

Pages

8

Series

CHEMISTRY: A EUROPEAN JOURNAL, Volume 26, issue 32, pp. 7250-7257

Abstract

The Mn-III/Mn-II 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, Mn-III 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 Ti-IV or/and V-V on Mn-III 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 Mn-II 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 Ti-IV and V-V on Mn-III. At a comparable pH, the amount of Mn-III loss through disproportionation is decreased by a factor of 2.5 in the presence of Ti-IV or/and V-V. Therefore, V-V is an efficient substitute for Ti-IV to stabilize the Mn-III electrolyte for RFB applications.

Description

Keywords

manganese electrolyte, manganese disproportionation reaction, redox flow battery, titanium, vanadium, ALL-VANADIUM, ELECTROCHEMICAL OXIDATION, ENERGY, COUPLE, PERFORMANCE, GENERATION, REDUCTION, STORAGE, CARBON, STATES

Other note

Citation

Reynard, D, Maye, S, Peljo, P, Chanda, V, Girault, H H & Gentil, S 2020, ' Vanadium-Manganese Redox Flow Battery : Study of Mn-III Disproportionation in the Presence of Other Metallic Ions ', CHEMISTRY: A EUROPEAN JOURNAL, vol. 26, no. 32, pp. 7250-7257 . https://doi.org/10.1002/chem.202000340