Synthesis, Characterization and Evaluation of Pb Electroplated Carbon felts for Achieving Maximum Efficiency of Fe-Cr Redox Flow Cell

Abstract

To catalyze Cr(III)/Cr(II) redox couple, Pb was used as candidate catalysts. Pb has a remarkable behavior on reduction and oxidation of chromium couple to enhance the performance of Fe-Cr redox flow cell. In the present investigation catalyzed carbon felt substrates were used as electrodes on negative side which were electrochemically plated/ loaded with Pb from 0.05g to 1.2g. The cell comprising 0.8 g Pb loaded felt has shown 100% Chromium reduction efficiency, 98% coulombic efficiency and zero hydrogen gassing at 32 o C for 15 cycles of charge and discharge. 5liters of 1.3N FeCl 2 in 2N HCl as catholyte, 1.3N CrCl 3 in 2N HCl as anolyte containing 0.05N BiCl 3 as additive were used as electrolytes. The cell operated with Nafion-117 PFSA membrane. 100 cm 2 GFA grade carbon felts with 3mm thickness were utilized as electrodes at a current density of 50 mA/ cm 2 .

Recent Advances for Electrode Modifications in Flow Batteries: Properties, Mechanisms, and Outlooks

“…Tirukkovalluri et al. used CF substrate as the negative electrode for electrochemical Pd plating [76] . Pd had significantly reducing and oxidizing properties on the Cr 3+ /Cr 2+ redox couple, which improved the performance of ICFB.…”

Review of the Development of First‐Generation Redox Flow Batteries: Iron‐Chromium System

“…At 32 °C, the cell containing felts loaded with 0.8 g Pb demonstrated a CE of 98 %, EE of 68 %, and zero hydrogen evolution. [59] In addition, Tl was also deposited on the surface of the electrode to mitigate the hydrogen evolution, and its effect on the Cr 3 + /Cr 2 + redox reaction was studied. The results revealed that the application of Tl greatly promoted the Cr 3 + /Cr 2 + reaction and increased the overpotential of hydrogen.…”

“…Tirukkovalluri and Gorthi originally adopted Pb as the catalyst for the Cr 3+ /Cr 2+ redox couple. At 32 °C, the cell containing felts loaded with 0.8 g Pb demonstrated a CE of 98 %, EE of 68 %, and zero hydrogen evolution [59] . In addition, Tl was also deposited on the surface of the electrode to mitigate the hydrogen evolution, and its effect on the Cr 3+ /Cr 2+ redox reaction was studied.…”

Hydrogen evolution mitigation in iron-chromium redox flow batteries via electrochemical purification of the electrolyte

“…Another approach is to improve the reaction selectivity, either by utilizing catalysts or tuning the electrolyte composition to promote the desired redox reactions. To this end, bismuth (Bi) has been particularly well-studied in Fe-Cr RFBs and has consistently demonstrated an ability to promote the Cr redox reaction and suppress the HER, via direct nanoparticle deposition onto the negative electrode and/or as a negative electrolyte additive [31][32][33][34]. Lead (Pb) and indium (In) have shown similar benefits as catalysts and additives [34,35].…”

“…To this end, bismuth (Bi) has been particularly well-studied in Fe-Cr RFBs and has consistently demonstrated an ability to promote the Cr redox reaction and suppress the HER, via direct nanoparticle deposition onto the negative electrode and/or as a negative electrolyte additive [31][32][33][34]. Lead (Pb) and indium (In) have shown similar benefits as catalysts and additives [34,35]. Electrolyte composition is another avenue to address HER; beyond the use of additives, the concentrations of active species and supporting salt [36,37], as well as choice of supporting salt, can impact HER rates [11].…”