Practical Development of a ZnBr2 Flow Battery with a Fluidized Bed Anode Zinc-Electrode (original) (raw)
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The penetration of renewable sources (solar and wind power) into the power system network has been increasing in the recent years. As a result of this, there have been serious concerns over reliable and satisfactory operation of the power systems. One of the solutions being proposed to improve the reliability and performance of these systems is to integrate energy storage devices into the power system network. Zinc-bromine batteries systems among other energy storage technologies has appeared as one of the best options. This paper presents the performance of three different electrodes feeder materials (carbon, nickel and a titanium) coupled and investigated within a fabricated ZnBr2 cell system via numerical modelling, DDPM+DEM model in ANSYS Fluent to simulate an incorporated anode zinc-electrode and COMSOL Multiphysics for the electrochemical behavior of the cell. After introducing briefly other alternatives to store energy, ZnBr2 cell systems, and its mode of operation were then discussed, before focusing on the numerical modelling and simulation and the laboratory experiments. Several extensive electrochemical experiments were implemented on the cell to achieve fast deposition of zinc onto the electrode surface during charge and fast dissolution during discharge for high performance. The mechanical action of the fluidised design of electrode is intended to improve deposit morphology, obviate the risk of dendrite growth and provide high transport rates of reactant to and from the active electrode surface. In conclusion, this paper has analyzed electrochemical techniques like chronopotentiometry, cyclic voltammetry (CV), and electrochemical impedance spectroscopy that were used to understand the behavior of the zinc bromide cells at a particular flow rate of 166.7cm3 min−1 required to give good fluidization of the anode.
Trends in Technical and Scientific Research, 2021
Batteries with different chemistries and designs encounter various (redox reactions) to store energy through applying charges and discharges rates. Redox flow batteries systems such as zinc bromine batteries cells systems (ZnBr 2) can be enclosed with high surface area anode electrodes (reactors) and charged with some amount of added carbon particles for zinc deposition. The electrochemical reactions within a fabricated ZnBr 2 battery cell system have been investigated with the coupled inlets and outlets brass fitting materials (15mm and 30mm) of different anode and cathode electrolyte compositions. SEM analysis was explored on some charged particles collected from the anode reactor to identify all the existing elements within the deposited charged zinc particles after several charges. The investigated zinc particles were between 254 microns to 354 microns. The electrolyte composition includes 3 moles of KBr (535.51 grams), 1 mole of KCl (111.89 grams) as the cathode side electrolyte and 3 moles of ZnBr 2 (675 grams), 1 mole of ZnCl 2 (205 grams), and 1M of KCl (111.826 grams) as the anode electrolyte solution. Originally, this journal paper has discovered the importance of coupling chemically resistance materials to ZnBr 2 cells as investigated on the fabricated ZnBr 2 cell that was initially converted to a CuZn 2 battery cell system and reverted to the ideal ZnBr 2 cell system before using an SEM technique to identify separately the present elements.
Scientific issues of zinc‐bromine flow batteries and mitigation strategies
Exploration
Zinc-bromine flow batteries (ZBFBs) are promising candidates for the large-scale stationary energy storage application due to their inherent scalability and flexibility, low cost, green, and environmentally friendly characteristics. ZBFBs have been commercially available for several years in both grid scale and residential energy storage applications. Nevertheless, their continued development still presents challenges associated with electrodes, separators, electrolyte, as well as their operational chemistry. Therefore, rational design of these components in ZBFBs is of utmost importance to further improve the overall device performance. In this review, the focus is on the scientific understanding of the fundamental electrochemistry and functional components of ZBFBs, with an emphasis on the technical challenges of reaction chemistry, development of functional materials, and their application in ZBFBs. Current limitations of ZBFBs with future research directions in the development of high performance ZBFBs are suggested.
Journal of Physics: Conference Series, 2015
Zinc-bromine flow battery using aqueous electrolyte has advantages of cost effective and high energy density, but there still remains a problem improving stability and durability of electrolyte materials during long-time cell operation. This paper focuses on providing a homogeneous aqueous solution for durability and stability of zinc bromide electrolyte. For performance experiments of conventional and proposed electrolyte solutions, detailed cyclic voltammetry (CV) measurements (at a scan rate of 20 mV s-1 in the range of-1.5 V~1.5 V) are carried out for 40 cycles and five kinds of electrolytes containing which has one of additives, such as (conventionally) zinc chloride, potassium chloride, (newly) lithium perchlorate, sodium perchlorate and zeolite-Y are compared with the 2.0 M ZnBr 2 electrolyte, respectively. Experimental results show that using the proposed three additives provides higher anodic and cathodic peak current density of electrolytes than using other two conventional additives, and can lead to improved chemical reversibility of zinc bromide electrolyte. Especially, the solution of which the zeolite-Y added, shows enhanced electrochemical stability of zinc bromide electrolyte. Consequently, proposed electrolytes have a significant advantage in comparison with conventional electrolytes on higher stability and durability.
Zinc–bromine rechargeable batteries (ZBRBs) are one of the most powerful candidates for next-generation energy storage due to their potentially lower material cost, deep discharge capability, non-flammable electrolytes, relatively long lifetime and good reversibility. However, many opportunities remain to improve the efficiency and stability of these batteries for long-life operation. Here, we discuss the device configurations, working mechanisms and performance evaluation of ZBRBs. Both non-flow (static) and flow-type cells are highlighted in detail in this review. The fundamental electrochemical aspects, including the key challenges and promising solutions, are discussed, with particular attention paid to zinc and bromine half-cells, as their performance plays a critical role in determining the electrochemical performance of the battery system. The following sections examine the key performance metrics of ZBRBs and assessment methods using various ex situ and in situ/operando techniques. The review concludes with insights into future developments and prospects for high-performance ZBRBs.
Zn/Br2 cell: Effects of plated zinc and complexing organic phase
AIChE Journal, 1991
the aqueous phase. the separator material, N,,, and 0; the thickness of the separator S,; the MacMullin number and the thickness of the porous electrode, Nm,pE and SpE; the specific active surface area a of Notation c, = concentration of species i, mol/cm' c r = fractional change in the concentration of i over the time period f2t, c,,,, = feed concentration of species i, mol/cm' c,,,,~ = outlet concentration of species i from the electrochemical reactor, mol/cm'
Batteries will continue to encounter the problem of dendrite formation until a suitable solution is identified to address the problem. Dendrite formation can short circuit batteries cells, reduce their life span, voltages and cause mechanical abrasion to the cells. Batteries electrodes are part of the approaches that can be used to address these problems but depending on the fabrication of these electrodes and dimensions. Before fabricating and incorporating a real anode reactor to a fabricated ZnBr 2 cell system, it was necessary to model the behaviour with injected carbon particles in between 254 microns to 354 microns and simulate the geometry in COMSOL to observe their interaction with the electrolyte. This study investigates the performances of a designed anode reactor and to observe within the reactor the effect of having a uniform and non-uniform current density distribution before the fabrication, physically charge and incorporating it to the anode-side of ZnBr 2 cell system.
Journal of energy and power engineering, 2015
The most critical disadvantages of the Zn-air flow battery system are corrosion of the zinc, which appears as a high self-discharge current density and a short cycle life due to the non-uniform, dendritic, zinc electrodeposition that can lead to internal short-circuit. In our efforts to find a dendrite-free Zn electrodeposition which can be utilized in the Zn-air flow battery, the surface morphology of the electrolytic Zn deposits on a polished polymer carbon composite anode in alkaline, additive-free solutions was studied. Experiments were carried out with 0.1 M, 0.2 M and 0.5 M zincate concentrations in 8 M KOH. The effects of different working conditions such as: elevated temperatures, different current densities and different flow velocities, on current efficiency and dendrite formation were investigated. Specially designed test flow-cell with a central transparent window was employed. The highest Coulombic efficiencies of 80%-93% were found for 0.5 M ZnO in 8 M KOH, at increased temperatures (50-70 °C), current densities of up to 100 mA•cm-2 and linear electrolyte flow velocities higher than 6.7 cm•s-1 .
Mechanism and Optimizations of Aqueous Zinc-ion Battery
Highlights in Science, Engineering and Technology
Nowadays, more and more problems of environmental deterioration make the development of environmentally friendly energy imminent. For the requirements of low cost, high security, and high efficiency, aqueous Zn-ion batteries are a promising trend for research. In this paper, the mechanism of aqueous Zn-ion batteries will be illustrated in three aspects: cathode materials, zinc anode, and electrolytes. Moreover, possible alternatives for each part of the batteries will be comprehensively illustrated in detail. In addition, the challenges such as short capacity, zinc dendrites, and corrosion and passivation will be analyzed and the possible corresponding solutions will be proposed. Finally, a concise conclusion will be given.
Electrochimica Acta, 2021
This work aims to identify a suitable material for use as a zinc electrode substrate material in alkaline media, then employ this to study the effect of electrolyte flow rate and current density on zinc-nickel flow cell performance. Three metallic and four graphite composite materials are investigated, with the coulombic efficiency of zinc electrode charge / discharge cycling found to increase as hydrogen evolution onset potentials become more negative. A graphite / PVDF composite substrate demonstrates the highest coulombic efficiency at 96.7 % and the most negative hydrogen evolution onset potential at-1.595 V vs. Hg/HgO. Using this material, the effect of electrolyte flow rate and current density on a zinc-nickel flow cell is investigated. Zinc morphology and flow cell performance is related to the ratio of applied current density to limiting current density. At values between 0.47 and 1, boulder type zinc morphologies have been shown to occur, with smooth and compact zinc deposits resulting from current density ratios of 0.39 and below. Stable zinc-nickel flow cell performance is achieved over 200 cycles with coulombic, voltaic and energy efficiencies of 98.3, 88.1 and 86.6 % respectively, at a current density of 20 mA cm-2 .