• Title/Summary/Keyword: Vanadium Redox Flow Battery, VRFB

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Study on the Vanadium Redox Flow Battery using Cation Exchange Membrane and Ammonium Metavanadate (메타바나듐산암모늄과 양이온교환막을 활용한 바나듐 레독스 흐름전지에 관한 연구)

  • Jung, Bo-Young;Ryu, Cheol-Hwi;Hwang, Gab-Jin
    • Membrane Journal
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    • v.31 no.4
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    • pp.262-267
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    • 2021
  • The electrochemical performance of all vanadium redox flow battery (VRFB) using an electrolyte prepared from ammonium metavanadate and a cation exchange membrane (Nafion117) was evaluated. The electrochemical performance of VRFB was measured at a current density of 60 mA/cm2. The average current efficiency of VRFB using the electrolyte prepared from ammonium metavanadate was 94.9%, the average voltage efficiency was 82.2%, and the average energy efficiency was 78.0%. In addition, it was confirmed that the efficiencies of VRFB using the electrolyte prepared from ammonium metavanadate had almost the same value as the efficiencies of VRFB using the electrolyte prepared with vanadyl sulfate (VOSO4).

Recent Advance on Composite Membrane Based Vanadium Redox Flow Battery (복합막 기반 바나듐 레독스 흐름 전지의 최근 발전)

  • Kyobin Yoo;Rajkumar Patel
    • Membrane Journal
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    • v.33 no.5
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    • pp.233-239
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    • 2023
  • The transport properties of membranes used in vanadium redox flow batteries (VRFB) are fundamental in battery performance. High proton conductivity and low vanadium ion permeability must be achieved to achieve high battery performance. However, there is a trade-off relationship between proton conductivity and vanadium ion permeability. So, solving this trade-off relationship is crucial in VRFB development. Also, maintaining high coulombic efficiency, voltage efficiency, and energy efficiency is essential for high-performing VRFB. Recently, various attempts have been made, primarily on composite membranes and SPEEK membranes, to overcome the existing limit of Nafion membranes. VRFB is an essential class of rechargeable battery in composite membranes reviewed here.

Study on Current Collector for All Vanadium Redox Flow Battery (전바나듐계 레독스플로우전지용 집전체에 대한 연구)

  • Choi, Ho-Sang;Hwang, Gab-Jin;Kim, Jae-Chul;Ryu, Cheol-Hwi
    • Transactions of the Korean hydrogen and new energy society
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    • v.22 no.2
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    • pp.240-248
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    • 2011
  • All-vanadium redox flow battery (VRFB) has been studied actively as one of the most promising electrochemical energy storage systems for a wide range of applications such as electric vehicles, photovoltaic arrays, and excess power generated by electric power plants at night time. Among consisting elements of the VRFB, the ion exchange membrane and the electrode play important roles. In this study, carbon PVC coposite sheets for the VRFB have been developed and electrochemical characteristics investigated. Current collector for VRFB, carbon PVC composite sheets (CPCS), were prepared with G-1028 as a conducting particle, PVC as a polymer, Dibutyl phthalate (DBP) as a plasticizer and fumed Silica (FS) as a dispersion agent. CPCS has been shown to have the characteristics as an excellent current collector for VRFB and electrochemical properties of specific resistivity 0.31 ${\Omega}cm$, which were composed of G-1028 80 wt%, PVC 10 wt%, DBP 5 wt% and FS 5 wt%.

Performance of the Electrode for All-vanadium Redox Flow Battery (바나듐 레독스 흐름 전지용 전극의 성능 평가)

  • IN, DAE-MIN;SONG, YOUNG-JOON;LEE, DAE-YEOP;RYU, CHEOL-HWI;HWANG, GAB-JIN
    • Transactions of the Korean hydrogen and new energy society
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    • v.28 no.2
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    • pp.200-205
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    • 2017
  • The three electrodes (carbon felt) were tested in all-vanadium redox flow battery (VRFB) to confirm the its usefulness. The electrode property was measured by the CV (cyclic voltammetry) method. The current ratio of maximum peak(IPA/IPC) in GF040BH5 and GF051BH3 had almost the same value compared to that in XF30A. The performances of VRFB using the each electrode were measured during 5 cycles of charge-discharge at the current density of $60mA/cm^2$. An average energy efficiency of the VRFB was 77.8%, 77.3%, and 79.2% for XF30A, GF040BH5 and GF051BH3, respectively. It was confirmed from the data that GF040BH5 and GF051BH3 is well suited for use in a VRFB as a electrode, like XF30A.

Suppressing Effect of Hydrogen Evolution by Oxygen Functional Groups on CNT/ Graphite Felt Electrode for Vanadium Redox Flow Battery (탄소나노튜브/흑연펠트 전극의 산소작용기를 활용한 바나듐 레독스 흐름 전지의 수소발생 억제 효과)

  • Kim, Minseong;Ko, Minseong
    • Journal of the Korean institute of surface engineering
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    • v.54 no.4
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    • pp.164-170
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    • 2021
  • Vanadium redox flow batteries (VRFB) have emerged as large-scale energy storage systems (ESS) due to their advantages such as low cross-contamination, long life, and flexible design. However, Hydrogen evolution reaction (HER) in the negative half-cell causes a harmful influence on the performance of the VRFB by consuming current. Moreover, HER hinders V2+/V3+ redox reaction between electrode and electrolyte by forming a bubble. To address the HER problem, carbon nanotube/graphite felt electrode (CNT/GF) with oxygen functional groups was synthesized through the hydrothermal method in the H2SO4 + HNO3 (3:1) mixed acid solution. These oxygen functional groups on the CNT/GF succeed in suppressing the HER and improving charge transfer for V2+/V3+ redox reaction. As a result, the oxygen functional group applied electrode exhibited a low overpotential of 0.395 V for V2+/V3+ redox reaction. Hence, this work could offer a new strategy to design and synthesize effective electrodes for HER suppression and improving the energy density of VRFB.

Porous Electrodes with Lower Impedance for Vanadium Redox Flow Batteries

  • Park, Su Mi;Kim, Haekyoung
    • Korean Chemical Engineering Research
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    • v.53 no.5
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    • pp.638-645
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    • 2015
  • Vanadium redox flow batteries (VRFBs) have been investigated for their potential utility as large energy storage systems due to their advantageous performances in terms of long cycle life, high energy efficiency, low cost, and flexible design. Carbon materials are typically used as electrodes in redox reactions and as a liquid electrolyte support. The activities, surface areas, and surface morphologies of porous carbon materials must be optimized to increase the redox flow battery performance. Here, to reduce the resistance in VRFBs, surface-modified carbon felt electrodes were fabricated, and their structural, morphological, and chemical properties were characterized. The surface-modified carbon felt electrode improved the cycling energy efficiencies in the VRFBs, from 65% to 73%, due to the improved wettability with electrolyte. From the results of impedances analysis with proposed fitting model, the electrolyte-coupled polarization in VRFB dramatically decreased upon modification of carbon felt electrode surface. It is also demonstrated that the compressibility of carbon felt electrodes was important to the VRFB polarization, which are concerned with mass transfer polarization. The impedance analysis will be helpful for obtaining better and longer-lived VRFB performances.

Change of the Efficiency in All-Vanadium Redox Flow Battery with Current Density (전류밀도에 따른 바나듐 레독스 흐름 전지의 효율 변화)

  • CHOI, HO-SANG;IN, DAE-MIN;SONG, YOUNG-JOON;RYU, CHEOL-HWI;HWANG, GAB-JIN
    • Transactions of the Korean hydrogen and new energy society
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    • v.28 no.5
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    • pp.531-535
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    • 2017
  • The performance of all-vanadium redox flow battery (VRFB) was tested with an increase of the current density. APS membrane (anion exchange membrane) and GF050CH (cabon felt) were used as a separator and electrode, respectively. An average energy efficiency of the VRFB was 79.5%, 68.1%, and 62.8% for the current density of $60mA/cm^2$, $120mA/cm^2$, and $160mA/cm^2$, respectively. It was confirmed that VRFB can be used as a energy storage system at the higher current density even if the energy efficiency was deceased about 21%.

Aminopropyl Functionalized Silica Nanoparticle Dispersed Nafion Composite Membranes for Vanadium Redox Flow Batteries (아미노프로필 관능기를 갖는 실리카 나노 입자가 분산된 나피온 복합막을 이용한 바나듐 레독스 흐름 전지)

  • Lee, Doohee;Yu, Duk Man;Yoon, Sang Jun;Kim, Sangwon;So, Soonyong;Hong, Young Taik
    • Membrane Journal
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    • v.30 no.5
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    • pp.307-318
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    • 2020
  • Conventional perfluorinated sulfonic acid membrane, Nafion is widely used for vanadium redox flow battery (VRFB). It is desired to prevent vanadium ion permeation through a membrane to retain the capacity, and to keep the cell efficiency of a VRFB. Highly proton conductive and chemically stable Nafion membranes, however, suffer from high vanadium permeation, which induce the reduction in charge and discharge capacity by side reactions of vanadium ions. In this study, to resolve the issue, silica nanoparticles, which are functionalized with 3-aminopropyl group (fS) are introduced to enhance the long-term performance of a VRFB by lowering vanadium permeation. It is expected that amine groups on silica nanoparticles are converted to positive ammonium ion, which could deteriorate positively charged vanadium ions' crossover by Gibbs-Donnan effect. There is reduction in proton conductivity may due to acid-base complexation between fS and Nafion side chains, but ion selectivity of proton to vanadium ion is enhanced by introducing fS to Nafion membranes. With the composite membranes of Nafion and fS, VRFBs maintain their discharge capacity up to 80% at a high current density of 150 mA/㎠ during 200 cycles.

Development of Activated Graphite Felt Electrode Using Ozone and Ammonia Consecutive Post Treatments for Vanadium Redox Flow Batteries (오존, 암모니아 순차적 처리를 통한 바나듐 레독스 흐름 전지용 활성화 카본 펠트 전극 개발)

  • CHOI, HANSOL;KIM, HANSUNG
    • Transactions of the Korean hydrogen and new energy society
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    • v.32 no.4
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    • pp.256-262
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    • 2021
  • A carbon felt electrode was prepared using ozone and ammonia sequential treatment and applied as an electrode for a vanadium redox flow battery (VRFB). The physical and electrochemical analyses demonstrate that the oxygen groups facilitate nitrogen doping in the carbon felt. Carbon felt (J5O3+NH3), which was subjected to ammonia heat treatment after ozone treatment, showed higher oxygen and nitrogen contents than carbon felt (J5NH3+O3), which was subjected to ammonia heat treatment first and then ozone treatment. From the charging/discharging of VRFB, the J5O3+NH3 carbon felt electrode showed 14.4 Ah/L discharge capacity at a current density of 150 mA /cm2, which was 15% and 33% higher than that of J5NH3+O3 and non-activated carbon felt (J5), respectively. These results show that ozone and ammonia sequential treatment is an effective carbon felt activation method to increase the performance of the vanadium redox flow battery.

Numerical Study About Compression Effect of Porous Electrodes on the Performance of Redox Flow Batteries (다공성 전극의 압축률이 레독스흐름전지의 성능에 미치는 영향에 대한 수치해석적 연구)

  • Jeong, Daein;Jung, Seunghun
    • Journal of ILASS-Korea
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    • v.22 no.2
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    • pp.69-79
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    • 2017
  • When designing a redox flow battery system, compression of battery stack is required to prevent leakage of electrolyte and to reduce contact resistance between cell components. In addition, stack compression leads to deformation of the porous carbon electrode, which results in lower porosity and smaller cross-sectional area for electrolyte flow. In this paper, we investigate the effects of electrode compression on the cell performance by applying multi-dimensional, transient model of all-vanadium redox flow battery (VRFB). Simulation result reveals that large compression leads to greater pressure drop throughout the electrodes, which requires large pumping power to circulate electrolyte while lowered ohmic resistance results in better power capability of the battery. Also, cell compression results in imbalance between anolyte and catholyte and convective crossover of vanadium ions through the separator due to large pressure difference between negative and positive electrodes. Although it is predicted that the battery power is quickly improved due to the reduced ohmic resistance, the capacity decay of the battery is accelerated in the long term operation when the battery cell is compressed. Therefore, it is important to optimize the battery performance by taking trade-off between power and capacity when designing VRFB system.