The characteristics and performance of hybrid redox flow batteries with zinc negative electrodes for energy storage (original) (raw)
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ChemPlusChem, 2015
Development and progress in Zn-Ce flow batteries are comprehensively reviewed. Electrode thermodynamics, electrode kinetics and cell performance aspects are included. The kinetics of Ce redox reactions in sulphuric and methanesulfonic acids are summarised. The critical aspects of zinc deposition and stripping in methanesufonic acid are considered. The performance of laboratory half-cells and flow cells is illustrated. Pilot-scale performance of a flow cell is illustrated and further research is highlighted.
The Zn–Ce flow battery is a recently introduced hybrid redox flow battery (RFB) but has been extensively studied in the laboratory and at the industrial pilot scale since its introduction in 2005. The cell has the highest open-circuit cell potentials amongst aqueous RFBs, which can exceed 2.4 V at full charge. Although original patents were filed in 2004 and 2005, the history of the half-cell reactions stretches back many decades, with the CeIV/CeIII redox couple being well studied in sulfuric acid as a redox mediator in organic electrosynthesis or in nitric acid for specialist cleaning in the chemical and nuclear industries; in addition, zinc deposition and stripping in acid media are well known in hydrometallurgy and electroplating of metals as well as in other secondary batteries using zinc negative electrodes. Methanesulfonic acid electrolytes were introduced in surface finishing several decades ago but their use in flow batteries is only 20 years old. This Review considers the thermodynamics and kinetics of the electrode reactions (desired and secondary) in each half-cell, operational variables, materials for cell components, cell design and performance of the zinc–cerium flow battery. Continuing challenges are highlighted and critical research needs for the science and technological development are considered.
Screening of effective electrolyte additives for zinc-based redox flow battery systems
Journal of Power Sources, 2019
The purpose of this work is to assess the suitability of potential electrolyte additives for zinc morphology control and improved electrochemical performance of the zinc electrode for application in zinc based redox flow battery (RFB) systems. Based on existing literature in the field, sixteen candidates are selected, including four metallic additives, two non-ionic surfactants and ten quaternary ammonium compounds. The electrochemical performance of the zinc electrode is assessed using cyclic voltammetry, linear sweep voltammetry and zinc half-cell cycling tests using chronopotentiometry. Zinc electrodepositions are carried out using chronopotentiometry in order to assess the effect of additives on zinc morphology with scanning electron microscopy. Based on zinc reduction and oxidation reaction potentials, the cycling efficiencies, and the effect on zinc morphology, the most promising additives of those tested are tetraethylammonium hydroxide and tetraethylammonium bromide. Both provide smooth and compact zinc deposits and zinc electrode coulombic efficiencies of 95-97 %
Review of the Research Status of Cost-Effective Zinc–Iron Redox Flow Batteries
Batteries
Zinc–iron redox flow batteries (ZIRFBs) possess intrinsic safety and stability and have been the research focus of electrochemical energy storage technology due to their low electrolyte cost. This review introduces the characteristics of ZIRFBs which can be operated within a wide pH range, including the acidic ZIRFB taking advantage of Fen+ with high solubility, the alkaline ZIRFB operating at a relatively high open-circuit potential and current densities, and the neutral ZIRFB providing a non-toxic, harmless, and mild environment. No matter what kind of ZIRFB, there are always zinc dendrites limiting areal capacity on the anode, which has become an obstacle that must be considered in zinc-based RFBs. Therefore, we focus on the current research progress, especially the summarizing and analysis of zinc dendrites, Fe(III) hydrolysis, and electrolytes. Given these challenges, this review reports the optimization of the electrolyte, electrode, membrane/separator, battery structure, and ...
Progress in redox flow batteries, remaining challenges and their applications in energy storage
RSC Advances, 2012
Redox flow batteries, which have been developed over the last 40 years, are used to store energy on the medium to large scale, particularly in applications such as load levelling, power quality control and facilitating renewable energy deployment. Various electrode materials and cell chemistries have been proposed; some of the successful systems have been demonstrated on a large-scale in the range of 10 kW-10 MW. Enhanced performance is attributable to the improvements in electrodes, separator materials and an increasing awareness of cell design. This comprehensive review provides a summary of the overall development of redox flow battery technology, including proposed chemistries, cell components and recent applications. Remaining challenges and directions for further research are highlighted.
2018
The growing number of electric vehicles worldwide demands increasing electricity generation from renewable sources such as wind and solar in order to render these vehicles CO 2 neutral. However, these systems are very intermittent and need to be coupled with high capacity and fast responding energy storage systems. Zinc-air flow batteries are designed for this stationary application, using the inexpensive, safe and abundant metal zinc as active storing material. In the project Luziflow all battery components are investigated and improved regarding the efficiency during cycling and the long-term stability during operation. On the negative zinc electrode, new insights have been gained on dendrite-free zinc deposition during charging and with flowing electrolyte. On the positive air electrode stable bifunctional electrode designs with high catalytic activity have been applied in longterm operation. The final aim of the project Luziflow will be the scale-up to 100 cm² and full cell operation.
An Energy Dense, Robust, Powerful Bipolar Zinc-Ferrocene Redox Flow Battery
2020
Redox flow batteries (RFBs) have been recognized as a promising option for scalable and dispatchable renewable energy storage (e.g. solar and wind energy). Zinc metal represents a low cost, high capacity anode material to develop high energy density aqueous redox flow batteries. However, the energy storage applications of traditional inorganic Zn halide flow batteries are primarily plagued by the material challenges of traditional halide cathode electrolytes (e.g. bromine) including corrosion, toxicity, and severe crossover. As reported here, we have developed a bipolar Zinc-ferrocene salt compound, Zinc 1,1’-bis(3-sulfonatopropyl)ferrocene, Zn[Fc(SPr)2] (1.80 M solubility or 48.2 Ah/L charge storage capacity) – a robust, energy-dense, bipolar redox-active electrolyte material for high performance Zn organic RFBs. Using a low-cost porous Daramic membrane, the Zn[Fc(SPr)2] aqueous organic redox flow battery (AORFB) has worked in dual-flow and single-flow modes. It has manifested outs...
Electrochimica Acta, 2011
Electrodeposition and dissolution of zinc in methanesulfonic acid were studied as the negative electrode reactions in a hybrid redox flow battery. Cyclic voltammetry at a rotating disk electrode was used to characterize the electrochemistry and the effect of process conditions on the deposition and dissolution rate of zinc in aqueous methanesulfonic acid. At a sufficiently high current density, the deposition process became a mass transport controlled reaction. The diffusion coefficient of Zn 2+ ions was 7.5 × 10 −6 cm 2 s −1 . The performance of the zinc negative electrode in a parallel plate flow cell was also studied as a function of Zn 2+ ion concentration, methanesulfonic acid concentration, current density, electrolyte flow rate, operating temperature and the addition of electrolytic additives, including potassium sodium tartarate, tetrabutylammonium hydroxide, and indium oxide. The current-, voltage-and energy efficiencies of the zinc-half cell reaction and the morphologies of the zinc deposits are also discussed. The energy efficiency improved from 62% in the absence of additives to 73% upon the addition of 2 × 10 −3 mol dm −3 of indium oxide as a hydrogen suppressant. In aqueous methanesulfonic acid with or without additives, there was no significant dendrite formation after zinc electrodeposition for 4 h at 50 mA cm −2 .
This paper considers the effects of electrolyte resistivity and inter-electrode gap on the simulated cell potential of an idealized Zn-Ce unit flow cell as a function of applied current density. The thermodynamic, kinetic and ohmic components of cell potential in a redox flow battery (RFB) are taken into account. This is important in the Zn-Ce RFB, where the positive electrode reaction tends to govern cell performance. The ionic conductivity of methanesulfonic acid (MSA) and typical electrolytes reported in the literature was measured as a function of MSA concentration and temperature. At 50◦C, the ionic resistivity of the positive and negative electrolytes is 3.0 cm and 4.8 cm respectively, for the most favorable electrolyte composition. The simulated cell potential showed that high surface-area electrodes were beneficial to the cell performance, while electrolytes containing 0.8 mol dm–3 Ce(III) and 1.5 mol dm–3 Zn(II) produced the lowest ohmic drop, which decreased at higher temperatures. The activation overpotential and internal resistance can be the main potential loss component, depending on electrolyte composition, cell design and electrode materials. The effect of cell geometry on the cell potential was also assessed, larger inter-electrode gaps significantly increasing potential losses.
Redox flow batteries for the storage of renewable energy: A review
Renewable and Sustainable Energy Reviews, 2014
The need for grid-connected energy storage systems will grow worldwide in the next future due to the expansion of intermittent renewable energy sources and the inherent request for services of power quality and energy management. Electrochemical storage systems will be a solution of choice in many applications because of their localization flexibility, efficiency, scalability, and other appealing features. Among them redox flow batteries (RFBs) exhibit very high potential for several reasons, including power/ energy independent sizing, high efficiency, room temperature operation, and extremely long charge/ discharge cycle life. RFB technologies make use of different metal ion couples as reacting species. The best-researched and already commercially exploited types are all-vanadium redox batteries, but several research programs on other redox couples are underway in a number of countries. These programs aim at achieving major improvements resulting in more compact and cheaper systems, which can take the technology to a real breakthrough in stationary grid-connected applications.