Effects of aluminum, iron, and manganese sulfate impurities on the vanadium redox flow battery

Pahlevaninezhad, Maedeh; Pahlevani, Majid; Roberts, Edward P.L.

doi:10.1016/j.jpowsour.2022.231271

Cited by 22 publications

(43 citation statements)

References 53 publications

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“…11 This trend confirms that vanadium species crossover is the main reason for CE losses. 2 In addition, the use of a thinner membrane (Nafion 115) led to a lower CE than the thicker Nafion 117, confirming the vanadium permeability and selfdischarge results. 12 A higher CE was observed in the case of EEG-coated membranes since the graphene reduces the vanadium permeability without increasing the membrane thickness.…”

Section: Membrane Properties Figures 4 and S5mentioning

confidence: 94%

“…As the current density increases, the VE of the VRFB was observed to decrease (Figure 6c) due to increasing overpotential (including kinetic, Ohmic, and mass transport overpotential). 2,12 Due to the lower area specific resistance of the thinner Nafion 115 membrane, around 2% higher VE was observed for this membrane than for Nafion 117. 12 Although the area specific resistance of the EEG-coated membranes was higher than their bare Nafion counterparts (Figure 5b), the presence of the graphene coating led to a 10 and 5% higher VE for EEG coating on Nafion 117 and Nafion 115, respectively (Figure 6c), indicating that the total overpotential was reduced.…”

Section: Membrane Properties Figures 4 and S5mentioning

confidence: 98%

“…The film was subsequently compressed to a surface pressure of approximately 20 mN m −1 at a rate of 5 mm min −1 , as measured with a paper Wilhelmy plate setup. Following compression, the coated area of the trough was reduced from approximately 144 cm 2 to around 104 cm 2 , and the excess water was carefully removed from the trough using a vacuum aspirator which was placed to the left of the leftmost Teflon barrier so that the layer of graphene was lowered onto the surface of the substrate(s).…”

Section: Graphene Composite Membrane Preparationmentioning

confidence: 99%

“…The membrane was soaked in DI water for 24 h before use. 2,48,49 Figure 2 shows a schematic of the VRFB flow cell testing system used in this study. In all experiments, the negative and positive electrolyte tanks each contained 20 mL of 1.6 M vanadium electrolyte in 3 M H 2 SO 4 .…”

Section: Area Specific Resistance and Proton Conductivitymentioning

confidence: 99%

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Exfoliated Graphene Composite Membrane for the All-Vanadium Redox Flow Battery

Pahlevaninezhad,

Miller,

Yang

et al. 2023

ACS Appl. Energy Mater.

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Vanadium redox flow batteries are emerging as a promising grid storage solution. Unlike competing flow battery concepts, these utilize vanadium in both the catholyte and anolyte chambers which enables easy regeneration and balancing of the cell upon crossover of species through the membrane during long-term use. To increase the time between regeneration cycles and to improve the overall efficiency of vanadium flow batteries, we investigate the use of an ultrathin, graphene coating on the surface of various Nafion membranes. Electrochemically exfoliated graphene (EEG) was dispersed at the air−water interface of a Langmuir−Blodgett trough, compressed, and transferred to Nafion 117 (180 μm thickness) and Nafion 115 (127 μm) membranes. Single-cell vanadium redox flow batteries assembled with the coated membranes led to significantly higher energy efficiency (increased by 13%), power density (by 67%), and discharge capacity (by 17.5%) over 100 cycles compared to uncoated Nafion. The graphene layer was stable over cycling, and electrochemical impedance spectroscopy and self-discharge experiments indicated that the improved battery performance is due to a combination of reduced vanadium crossover and enhanced electrochemical activity provided by the graphene at the electrode surface.

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Section: Membrane Properties Figures 4 and S5mentioning

confidence: 94%

Section: Membrane Properties Figures 4 and S5mentioning

confidence: 98%

Section: Graphene Composite Membrane Preparationmentioning

confidence: 99%

Section: Area Specific Resistance and Proton Conductivitymentioning

confidence: 99%

See 2 more Smart Citations

Exfoliated Graphene Composite Membrane for the All-Vanadium Redox Flow Battery

Pahlevaninezhad,

Miller,

Yang

et al. 2023

ACS Appl. Energy Mater.

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“…The application scope of vanadium has expanded beyond iron-/steelmaking, military, and medical industries [1][2][3][4] to include functional materials (e.g., nanocomposites), high-performance alloys, and all-vanadium liquid-flow batteries [5][6][7][8][9][10][11][12][13]. In particular, the abovementioned batteries represent a new high-efficiency energy storage technology and energy-development direction, which highlights the strategic importance of vanadium resources [14][15][16].…”

Section: Introductionmentioning

confidence: 99%

Short-Process Preparation of High-Purity V2O5 from Shale Acid Leaching Solution via Chlorination

Huang

Zhang

et al. 2023

Processes

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The conventional V2O5 preparation processes include ion exchange, chemical precipitation, solvent extraction, and other processes. Given the long process and complex operation nature of traditional V2O5 production methods, we herein developed a short-process, low-temperature, and convenient operation method of isolating vanadium (in the form of V2O5) from shale acid leaching solution. The acid leaching solution was oxidized with NaClO3 and pH-adjusted with NaOH to form a vanadium-containing precipitate, which was mixed with AlCl3 (V:AlCl3 = 1:5, mol/mol) and roasted for 120 min at 170 °C to afford vanadium oxytrichloride (VOCl3) with a purity of 99.59%. In addition, the vanadium-containing precipitate was mixed with AlCl3 and NaCl (V:AlCl3:NaCl = 3:12:8, mol/mol/mol) and roasted for 120 min at 170 °C to afford VOCl3 with a purity of 99.94%. VOCl3 (purity of 99.94%) was dissolved in ultrapure water, and the solution (32 gvanadium/L) was treated with NH3·H2O (NH3:V = 1.34, mol/mol) at 50 °C for 120 min. The obtained precipitate (vanadium precipitation rate = 99.28%) was roasted at 550 °C for 3 h to afford high-purity vanadium pentoxide (V2O5) with a purity of 99.86%. Compared with the traditional hydrometallurgical method of V2O5 preparation, our method avoided solvent extraction and other undesired processes and the overall process flow is greatly shortened, thus having high practical value.

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Ammonium Bifluoride‐Etched MXene Modified Electrode for the All−Vanadium Redox Flow Battery

Pahlevaninezhad,

Sadri,

Momodu

et al. 2024

Batteries & Supercaps

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The development of electrodes with high performance and long–term stability is crucial for commercial application of vanadium redox flow batteries. This study compared the performance of VRFB with thermal‐treated and MXene‐modified carbon paper. To prepare the MXene, a modified‐etching process with ammonium‐bifluoride (NH4HF2) led to a mild and efficient conversion of the MAX‐phase to MXene compared to etching process with hydrofluoric‐acid (HF). Electron microscopy studies revealed that the etching process with NH4HF2 led to MXene nanostructures with a large interlayer spacing. The results show that at a current density of 60 mA cm‐2, the voltage efficiency with a NH4HF2‐etched MXene‐modified negative electrode increased by 25.5%, 12.5%, and 4% in comparison with pristine, thermal‐treated, and HF‐etched MXene‐modified electrode, respectively. The maximum power density of the battery was increased by more than 40%. In long–term cycling experiments the MXene‐modified electrode exhibited excellent stability over 1000 cycles of charge‐discharge, with 0.05% discharge capacity decay per cycle, amongst the lowest values reported to date and four times lower than for thermally‐treated electrode. The superior performance was linked to the improved electrical conductivity and wettability, higher interlayer spacing, and lower charge transfer resistance for the V2+/V3+ redox reaction.

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Effects of aluminum, iron, and manganese sulfate impurities on the vanadium redox flow battery

Cited by 22 publications

References 53 publications

Exfoliated Graphene Composite Membrane for the All-Vanadium Redox Flow Battery

Exfoliated Graphene Composite Membrane for the All-Vanadium Redox Flow Battery

Short-Process Preparation of High-Purity V2O5 from Shale Acid Leaching Solution via Chlorination

Ammonium Bifluoride‐Etched MXene Modified Electrode for the All−Vanadium Redox Flow Battery

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