The Experts below are selected from a list of 4023 Experts worldwide ranked by ideXlab platform

Liquan Chen - One of the best experts on this subject based on the ideXlab platform.

  • sulfonated poly ether ether ketone mesoporous silica hybrid membrane for high performance vanadium Redox Flow Battery
    Journal of Power Sources, 2014
    Co-Authors: Wenjing Dai, Xinping Qiu, Liquan Chen
    Abstract:

    Hybrid membranes of sulfonated poly(ether ether ketone) (SPEEK) and mesoporous silica SBA-15 are prepared with various mass ratios for vanadium Redox Flow Battery (VRB) application and investigated in detail. The hybrid membranes are dense and homogeneous with no visible hole as the SEM and EDX images shown. With the increasing of SBA-15 mass ratio, the physicochemical property, VO 2þ perme-

  • research progress of vanadium Redox Flow Battery for energy storage in china
    Renewable Energy, 2008
    Co-Authors: Kelong Huang, Xiaogang Li, Liquan Chen
    Abstract:

    Principle and characteristics of vanadium Redox Flow Battery (VRB), a novel energy storage system, was introduced. A research and development united laboratory of VRB was founded in Central South University in 2002 with the financial support of Panzhihua Steel Corporation. The laboratory focused their research mainly on the selection and preparation of electrode materials, membrane material and modification, stable concentrated electrolyte producing approach, test cell configuration design and optimization. Some relevant foundation problems, such as state of vanadium in sulfurous acid with various additives, the difference of electrochemical reaction rate in anode and in cathode, the crossover of vanadium ions and so on, have been emphasized. The details of these studies have been given and discussed. A 5kW VRB stack was fabricated in the laboratory and its performances, especially electrochemical performance such as voltage efficiencies, energy efficiencies, and durability, were fully tested. The results will be shown in the talk.

  • nafion sio2 hybrid membrane for vanadium Redox Flow Battery
    Journal of Power Sources, 2007
    Co-Authors: Xinping Qiu, Liquan Chen
    Abstract:

    Abstract Sol–gel derived Nafion/SiO2 hybrid membrane is prepared and employed as the separator for vanadium Redox Flow Battery (VRB) to evaluate the vanadium ions permeability and cell performance. Nafion/SiO2 hybrid membrane shows nearly the same ion exchange capacity (IEC) and proton conductivity as pristine Nafion 117 membrane. ICP-AES analysis reveals that Nafion/SiO2 hybrid membrane exhibits dramatically lower vanadium ions permeability compared with Nafion membrane. The VRB with Nafion/SiO2 hybrid membrane presents a higher coulombic and energy efficiencies over the entire range of current densities (10–80 mA cm−2), especially at relative lower current densities (

Wei Wang - One of the best experts on this subject based on the ideXlab platform.

  • towards an all vanadium Redox Flow Battery with higher theoretical volumetric capacities by utilizing the vo2 v3 couple
    Journal of Energy Chemistry, 2018
    Co-Authors: Wentao Duan, Zimin Nie, Xiaoliang Wei, Vincent L. Sprenkle, Vijayakumar Murugesan, Jamie P Kizewski, Aaron Hollas, David Reed, Wei Wang
    Abstract:

    Abstract An all-vanadium Redox Flow Battery with V(IV) as the sole parent active species is developed by accessing the VO2+/V3+ Redox couple. These batteries, referred to as V4RBs, possess a higher theoretical volumetric capacity than traditional VRBs. Copper ions were identified as an effective additive to boost the Battery performance.

  • ambipolar zinc polyiodide electrolyte for a high energy density aqueous Redox Flow Battery
    Nature Communications, 2015
    Co-Authors: Zimin Nie, Jun Liu, Vincent L. Sprenkle, M Vijayakumar, Wei Wang
    Abstract:

    Conventional Redox Flow batteries have low energy densities. Here the authors present an aqueous Redox Flow Battery with an ambipolar and bifunctional zinc-polyiodide electrolyte, which exhibits an energy density approaching to that of lithium ion batteries.

  • nanoporous polytetrafluoroethylene silica composite separator as a high performance all vanadium Redox Flow Battery membrane
    Advanced Energy Materials, 2013
    Co-Authors: Xiaoliang Wei, Qingtao Luo, Zimin Nie, Baowei Chen, Vincent L. Sprenkle, Kevin L Simmons, Wei Wang
    Abstract:

    A novel low-cost nanoporous polytetrafluoroethylene (PTFE)/silica composite separator has been prepared and evaluated for its use in an all-vanadium Redox Flow Battery (VRB). The separator consists of silica particles enmeshed in a PTFE fibril matrix. It possesses unique nanoporous structures with an average pore size of 38 nm and a porosity of 48%. These pores function as the ion transport channels during Redox Flow Battery operation. This separator provides excellent electrochemical performance in the mixed-acid VRB system. The VRB using this separator delivers impressive energy efficiency, rate capability, and temperature tolerance. In additon, the Flow cell using the novel separator also demonstrates an exceptional capacity retention capability over extended cycling, thus offering excellent stability for long-term operation. The characteristics of low cost, excellent electrochemical performance and proven chemical stability afford the PTFE/silica nanoporous separator great potential as a substitute for the Nafion membrane used in VRB applications.

  • fe v Redox Flow Battery electrolyte investigation and optimization
    Journal of Power Sources, 2013
    Co-Authors: Wei Wang, Qingtao Luo, Zimin Nie, Xiaoliang Wei, Baowei Chen, Zhenguo Yang, Vincent L. Sprenkle
    Abstract:

    Abstract The recently invented iron (Fe)/vanadium (V) Redox Flow Battery (IVB) system has attracted increasing attention because of its long-term cycling stability and low-cost membrane/separator. In this paper, we describe our extensive matrix study of factors such as electrolyte composition, state of charge (SOC), and temperature that influence the stability of electrolytes in both positive and negative half-cells. During the study, an optimized electrolyte that can be operated in a temperature range from −5 °C to 50 °C without precipitation is identified. Fe/V Flow cells using the optimized electrolyte and low-cost separator exhibit satisfactory cycling performance at different temperatures. Efficiencies, capacities, and energy densities of Flow batteries at various temperatures are studied.

  • anthraquinone with tailored structure for a nonaqueous metal organic Redox Flow Battery
    Chemical Communications, 2012
    Co-Authors: Wei Wang, Lelia Cosimbescu, Daiwon Choi, Zhenguo Yang
    Abstract:

    A nonaqueous, hybrid metal–organic Redox Flow Battery based on tailored anthraquinone structure is demonstrated to have an energy efficiency of ∼82% and a specific discharge energy density similar to those of aqueous Redox Flow batteries, which is due to the significantly improved solubility of anthraquinone in supporting electrolytes.

Zhensheng Mai - One of the best experts on this subject based on the ideXlab platform.

  • poly tetrafluoroethylene reinforced sulfonated poly ether ether ketone membranes for vanadium Redox Flow Battery application
    Journal of Power Sources, 2012
    Co-Authors: Hongzhang Zhang, Huamin Zhang, Zhensheng Mai, Wenping Wei
    Abstract:

    Abstract Poly(tetrafluoroethylene) reinforced sulfonated poly(ether ether ketone) (SPEEK/PTFE) composite membranes are prepared for vanadium Redox Flow Battery (VRB) application. Results show that SPEEK/PTFE composite membranes have lower water uptake and swelling ratio than that of SPEEK membranes due to the PTFE reinforcement. As a result, the composite membranes show higher elongation ratio and better mechanical stability than SPEEK membranes. VRB single cell tests are also carried out to further evaluate their performance. The batteries assembled with SPEEK/PTFE membranes exhibit higher columbic efficiency (CE) and energy efficiency (EE) than that of SPEEK membranes. Furthermore, the composite membranes show much better stability than pristine SPEEK, confirming that PTFE can effectively reinforce membranes to improve their chemical and mechanical stability under VRB operating condition.

  • ion exchange membranes for vanadium Redox Flow Battery vrb applications
    Energy and Environmental Science, 2011
    Co-Authors: Huamin Zhang, Hongzhang Zhang, Zhensheng Mai, Ivo F J Vankelecom
    Abstract:

    The vanadium Redox Flow Battery (VRB) has received wide attention due to its attractive features for large scale energy storage. The key material of a VRB is an ion exchange membrane (IEM) that prevents cross mixing of the positive and negative electrolytes, while still allowing the transport of ions to complete the circuit during the passage of current. This review focuses on all aspects related to IEMs that are of relevance to understand IEMs better. An overview of the general issues of VRBs will be given first, after which the role of the IEM will be outlined together with the material requirements for advanced alternative IEMs. Finally, the recent progress of IEMs in VRBs will be reviewed and directions will be given for the development of next-generation materials.

  • sulfonated poly tetramethydiphenyl ether ether ketone membranes for vanadium Redox Flow Battery application
    Journal of Power Sources, 2011
    Co-Authors: Huamin Zhang, Zhensheng Mai, Hua Dai
    Abstract:

    Abstract Sulfonated poly(tetramethydiphenyl ether ether ketone) (SPEEK) with various degree of sulfonation is prepared and first used as ion exchange membrane for vanadium Redox Flow Battery (VRB) application. The vanadium ion permeability of SPEEK40 membrane is one order of magnitude lower than that of Nafion 115 membrane. The low cost SPEEK membranes exhibit a better performance than Nafion at the same operating condition. VRB single cells with SPEEK membranes show very high energy efficiency (>84%), comparable to that of the Nafion, but at much higher columbic efficiency (>97%). In the self-discharge test, the duration of the cell with the SPEEK membrane is two times longer than that with Nafion 115. The membrane keeps a stable performance after 80-cycles charge–discharge test.

Huamin Zhang - One of the best experts on this subject based on the ideXlab platform.

  • poly tetrafluoroethylene reinforced sulfonated poly ether ether ketone membranes for vanadium Redox Flow Battery application
    Journal of Power Sources, 2012
    Co-Authors: Hongzhang Zhang, Huamin Zhang, Zhensheng Mai, Wenping Wei
    Abstract:

    Abstract Poly(tetrafluoroethylene) reinforced sulfonated poly(ether ether ketone) (SPEEK/PTFE) composite membranes are prepared for vanadium Redox Flow Battery (VRB) application. Results show that SPEEK/PTFE composite membranes have lower water uptake and swelling ratio than that of SPEEK membranes due to the PTFE reinforcement. As a result, the composite membranes show higher elongation ratio and better mechanical stability than SPEEK membranes. VRB single cell tests are also carried out to further evaluate their performance. The batteries assembled with SPEEK/PTFE membranes exhibit higher columbic efficiency (CE) and energy efficiency (EE) than that of SPEEK membranes. Furthermore, the composite membranes show much better stability than pristine SPEEK, confirming that PTFE can effectively reinforce membranes to improve their chemical and mechanical stability under VRB operating condition.

  • an optimal strategy of electrolyte Flow rate for vanadium Redox Flow Battery
    Journal of Power Sources, 2012
    Co-Authors: Huamin Zhang, Chenxi Sun, Yi Zou, Tao Zhang
    Abstract:

    Abstract Electrolyte Flow rate is a key factor that affects the performance of vanadium Redox Flow Battery (VRFB). A kilo-watt class VRFB system is fabricated to investigate the effects of electrolyte Flow rate on the performance of VRFB. The experiments show that the capacity increases, but the system efficiency decreases with the increase of electrolyte Flow rate. An optimal strategy of electrolyte Flow rate is proposed to improve the system efficiency and keep the high capacity simultaneously, which is corresponding to optimize the electrolyte Flow rate at different stages of charge and discharge processes. The results show that the system efficiency can be improved as high as 8% when keeping high capacity simultaneously.

  • Silica modified nanofiltration membranes with improved selectivity for Redox Flow Battery application
    Energy and Environmental Science, 2012
    Co-Authors: Hongzhang Zhang, Huamin Zhang, Xianfeng Li
    Abstract:

    Nanofiltration (NF) membranes with in situ assembled silica on the surface and in the pores were proposed and successfully prepared for vanadium Redox Flow Battery (VRB) applications to improve the vanadium/proton selectivity. VRBs assembled with the modified membranes exhibited much higher Coulombic efficiency than that with original NF membranes, while with a similar voltage efficiency. The results indicate that silica modification can effectively increase the membranes' ion selectivity and maintain good ion-conducting properties. The concept provides an effective way to fabricate high performance porous membranes for VRB applications.

  • a three dimensional model for negative half cell of the vanadium Redox Flow Battery
    Electrochimica Acta, 2011
    Co-Authors: Huamin Zhang, Feng Xing
    Abstract:

    Abstract A stationary, isothermal, three-dimensional model for negative half cell of the vanadium Redox Flow Battery is developed, which is based on the comprehensive conservation laws, such as charge, mass and momentum, together with a kinetic model for reaction involving vanadium species. The model is validated against the results calculated by the available two-dimensional model. With the given geometry of the negative half cell, the distributions of velocity, concentration, overpotential and transfer current density in the sections that are perpendicular and parallel to the applied current are studied. It is shown that the distribution of the electrolyte velocity in the electrode has significant impact on the distribution of concentration, overpotential and transfer current density. The lower velocity in the electrode will cause the higher overpotential, further result in the side reaction and corrosion of key materials locally. The development of the design of the vanadium Redox Flow Battery is discussed, and the further research is proposed.

  • ion exchange membranes for vanadium Redox Flow Battery vrb applications
    Energy and Environmental Science, 2011
    Co-Authors: Huamin Zhang, Hongzhang Zhang, Zhensheng Mai, Ivo F J Vankelecom
    Abstract:

    The vanadium Redox Flow Battery (VRB) has received wide attention due to its attractive features for large scale energy storage. The key material of a VRB is an ion exchange membrane (IEM) that prevents cross mixing of the positive and negative electrolytes, while still allowing the transport of ions to complete the circuit during the passage of current. This review focuses on all aspects related to IEMs that are of relevance to understand IEMs better. An overview of the general issues of VRBs will be given first, after which the role of the IEM will be outlined together with the material requirements for advanced alternative IEMs. Finally, the recent progress of IEMs in VRBs will be reviewed and directions will be given for the development of next-generation materials.

Hongzhang Zhang - One of the best experts on this subject based on the ideXlab platform.

  • poly tetrafluoroethylene reinforced sulfonated poly ether ether ketone membranes for vanadium Redox Flow Battery application
    Journal of Power Sources, 2012
    Co-Authors: Hongzhang Zhang, Huamin Zhang, Zhensheng Mai, Wenping Wei
    Abstract:

    Abstract Poly(tetrafluoroethylene) reinforced sulfonated poly(ether ether ketone) (SPEEK/PTFE) composite membranes are prepared for vanadium Redox Flow Battery (VRB) application. Results show that SPEEK/PTFE composite membranes have lower water uptake and swelling ratio than that of SPEEK membranes due to the PTFE reinforcement. As a result, the composite membranes show higher elongation ratio and better mechanical stability than SPEEK membranes. VRB single cell tests are also carried out to further evaluate their performance. The batteries assembled with SPEEK/PTFE membranes exhibit higher columbic efficiency (CE) and energy efficiency (EE) than that of SPEEK membranes. Furthermore, the composite membranes show much better stability than pristine SPEEK, confirming that PTFE can effectively reinforce membranes to improve their chemical and mechanical stability under VRB operating condition.

  • Silica modified nanofiltration membranes with improved selectivity for Redox Flow Battery application
    Energy and Environmental Science, 2012
    Co-Authors: Hongzhang Zhang, Huamin Zhang, Xianfeng Li
    Abstract:

    Nanofiltration (NF) membranes with in situ assembled silica on the surface and in the pores were proposed and successfully prepared for vanadium Redox Flow Battery (VRB) applications to improve the vanadium/proton selectivity. VRBs assembled with the modified membranes exhibited much higher Coulombic efficiency than that with original NF membranes, while with a similar voltage efficiency. The results indicate that silica modification can effectively increase the membranes' ion selectivity and maintain good ion-conducting properties. The concept provides an effective way to fabricate high performance porous membranes for VRB applications.

  • ion exchange membranes for vanadium Redox Flow Battery vrb applications
    Energy and Environmental Science, 2011
    Co-Authors: Huamin Zhang, Hongzhang Zhang, Zhensheng Mai, Ivo F J Vankelecom
    Abstract:

    The vanadium Redox Flow Battery (VRB) has received wide attention due to its attractive features for large scale energy storage. The key material of a VRB is an ion exchange membrane (IEM) that prevents cross mixing of the positive and negative electrolytes, while still allowing the transport of ions to complete the circuit during the passage of current. This review focuses on all aspects related to IEMs that are of relevance to understand IEMs better. An overview of the general issues of VRBs will be given first, after which the role of the IEM will be outlined together with the material requirements for advanced alternative IEMs. Finally, the recent progress of IEMs in VRBs will be reviewed and directions will be given for the development of next-generation materials.