Impact of electrolyte composition on the performance of the zinc–cerium redox flow battery system

The conversion of soluble cerium redox species in the zinc-cerium redox flow battery and other electrochemical processes can be carried out at planar and porous platinised titanium electrodes.The active area, current density, mass transfer coefficient and linear electrolyte flow velocity through these structures have a direct influence on the reaction yield and the relationship between cell potential and operational current density during charge and discharge of a flow battery. A quantitative and practical characterization of the reaction environment at these electrodes is required. The volumetric mass transfer coefficient, " $ has been calculated from limiting current measurements for Ce(IV) ion reduction in a laboratory, rectangular channel flow cell. This factor can be used to predict fractional conversion and required electrode dimensions. Highly porous platinised titanium felt shows superior " $ values and is wellsuited as a high performance electrode material.

Section: Cyclic Voltammetry and Rotating Disc Experimentsmentioning

confidence: 99%

Mass transport and active area of porous Pt/Ti electrodes for the Zn-Ce redox flow battery determined from limiting current measurements

Arenas

León

Walsh

2016

“…Previous work [30,31] has shown that using charge and discharge current densities lower than 25 mA cm −2 at a temperature of 60°C led to a sharp fall in the coulombic efficiency of the zinc deposition/dissolution process, from ~96% down to ~81% for a 10 min charge (charge/discharge current density = 10 mA cm −2 ). The conventional Hull cell, with no flow, was thus used to explore if this fall was caused by the different nature of zinc deposits formed at these different densities.…”

Section: Resultsmentioning

confidence: 99%

“…Further investigation of this system was conducted by Plurion Ltd., the University of Southampton [27,28,29] and the University of Strathclyde [30,31,32,33]. Its great advantage is its power to weight ratio due to its high open circuit cell voltage (E cell = 2.4 V).…”

Section: Page 3 Of 25mentioning

confidence: 99%

“…Previous studies on the Zn-Ce flow cell have reported charge efficiencies of more than 90 % and energy efficiencies above 60 % at 10 mA cm −2 for over 100 cycles [30]. The material of choice there for the negative electrode was a polyvinyl ester or polyvinylidene fluoride-carbon composite material (BMA5) while a platinized titanium mesh was used as [29].…”

Section: Page 3 Of 25mentioning

confidence: 99%

See 1 more Smart Citation

Factors affecting the performance of the Zn-Ce redox flow battery

Nikiforidis

Cartwright

Hodgson

et al. 2014

Self Cite

This version is available at https://strathprints.strath.ac.uk/50808/ Strathprints is designed to allow users to access the research output of the University of Strathclyde. Unless otherwise explicitly stated on the manuscript, Copyright © and Moral Rights for the papers on this site are retained by the individual authors and/or other copyright owners. Please check the manuscript for details of any other licences that may have been applied. You may not engage in further distribution of the material for any profitmaking activities or any commercial gain. You may freely distribute both the url (https://strathprints.strath.ac.uk/) and the content of this paper for research or private study, educational, or not-for-profit purposes without prior permission or charge.Any correspondence concerning this service should be sent to the Strathprints administrator: strathprints@strath.ac.ukThe Strathprints institutional repository (https://strathprints.strath.ac.uk) is a digital archive of University of Strathclyde research outputs. It has been developed to disseminate open access research outputs, expose data about those outputs, and enable the management and persistent access to Strathclyde's intellectual output. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. AbstractThe Hull Cell was used to investigate the impact of current density j on the morphology and uniformity of zinc electrodeposited from a 2.5 mol dm −3 Zn 2+ solution in 1.5 mol dmmethanesulfonic acid at 40°C onto carbon-composite surfaces. The range of the applied deposition current density used was between 1 mA cm −2 and 100 mA cm −2 . Good, robust deposits were obtained when j ≥ 10 mA cm _2 whereas at j's lower than this, patchy films formed due to the competing hydrogen evolution reaction (HER) on the bare carboncomposite surface. An understanding of these effects and its application in the redox flow battery enabled both the coulombic and cell potential efficiencies to be maintained at relatively high values, 90% and 69% respectively, indicating a successful inhibition of the HER on the fully formed Zn layer. Flow velocity at the low Reynolds number in the cell (Re <200) had little impact on the electrochemical cell performance. Depletion of the cerium species became an issue for long charge times.

“…, with a redox potential of 1.15 V vs. Ag/AgCl/3.5 M KCl and which has been widely studied as positive electrolyte in redox flow batteries [24][25][26] was selected as the electroactive species in order to build asymmetric hybrid capacitors that use an activated carbon (AC) in the negative electrode and multiwalled carbon nanotubes (MWCNTs) or a modified graphite felt (GF) in the positive one.…”

Section: Introductionmentioning

confidence: 99%

Enhanced energy density of carbon-based supercapacitors using Cerium (III) sulphate as inorganic redox electrolyte

Díaz

González

Santamarı́a

et al. 2015

The energy density of carbon based supercapacitors (CBSCs) was significantly increased by the addition of an inorganic redox species [Ce 2 (SO 4 ) 3 ] to an aqueous electrolyte (H 2 SO 4 ). The development of the faradaic processes on the positive electrode not only significantly increased the capacitance but also the operational cell voltage of these devices (up to 1.5 V) due to the high redox potentials at which the Ce 3+ /Ce 4+ reactions occur. Therefore, in asymmetric CBSCs assembled using an activated carbon as negative electrode and MWCNTs as the positive one, the addition of Ce 2 (SO 4 ) 3 moderately increases the energy density of the device (from 1.24 W h kg -1 to 5.08 W h kg -1 ). When a modified graphite felt is used as positive electrode the energy density of the cell reaches values as high as 13.84 W h kg -1 . The resultant systems become asymmetric hybrid devices where energy is stored due to double layer formation in the negative electrode and the development of the faradaic process in the positive electrode, which acts as a battery-type electrode.