PDF Publication Title:
Text from PDF Page: 001
batteries Article Enhanced Surface Area Carbon Cathodes for the Hydrogen–Bromine Redox Flow Battery David P. Trudgeon and Xiaohong Li * Citation: Trudgeon, D.P.; Li, X. Enhanced Surface Area Carbon Cathodes for the Hydrogen–Bromine Redox Flow Battery. Batteries 2022, 8, 276. https://doi.org/10.3390/ batteries8120276 Academic Editors: Catia Arbizzani and Seiji Kumagai Received: 28 October 2022 Accepted: 1 December 2022 Published: 6 December 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). Renewable Energy Group, Department of Engineering, Faculty of Environment, Science and Economy, University of Exeter, Penryn Campus, Cornwall TR10 9FE, UK * Correspondence: x.li@exeter.ac.uk Abstract: The hydrogen–bromine redox flow battery is a promising energy storage technology with the potential for capital costs as low as 220 $ kWh−1 and high operational power densities in excess of 1.4 W cm−2. In this work, enhanced surface area bromine electrodes incorporating carbon black (CB) and graphene nanoplatelets (GnPs) on carbon paper and carbon cloth substrates were investigated, and the effect of electrolyte concentration on performance of the electrodes was studied. Carbon-black- modified electrodes are found to possess the largest electrochemically active surface areas, i.e., up to 11 times that of unmodified materials, while GnP electrodes are shown to have superior kinetic activity towards the bromine electrode reaction. In terms of performance, lower electrolyte concentrations are found to favour the improved kinetic parameters associated with graphene nanoplatelet electrodes, while highly concentrated electrolytes favour the larger electrochemically active surface area of carbon black electrodes. The optimal performance was achieved on a carbon-black-modified carbon cloth electrode in a 6 M HBr/2 M Br2 electrolyte concentration, with polarisation current densities approaching 1.6 A cm−2 at overpotentials of ±400 mV, and mean overpotentials of 364 mV during oxidation and 343 mV during reduction, resulting from bromine oxidation/reduction cycling tests at ±1.5 A cm−2. Keywords: flow batteries; carbon materials; nanomaterials; bromine electrodes 1. Introduction Energy storage technologies (ESTs) are advantageous to energy systems in several ways. The applications of ESTs for electrical infrastructure include the deferment of network reinforcement investment through load levelling, peak shaving services, and grid frequency regulation [1,2]. ESTs can also facilitate the implementation of electricity generation from renewable sources. Many renewable energy sources are intermittent and/or unpredictable, leading to gaps between demand and supply which can be managed by using ESTs [3,4]. Redox flow batteries (RFBs) are one type of EST that demonstrate promise for the applications outlined above. These have a number of desirable characteristics, including design flexibility, a long lifetimes, high efficiency, rapid response times, potentially low costs, and a lack of geographical requirements for deployment [3–8]. The hydrogen–bromine RFB was first reported in 1980 [9]. The operation of the H2-Br2 RFB involves the reduction of protons and evolution of gaseous hydrogen at the anode during charge and the oxidation of hydrogen during discharge, as shown in Reaction (1). At the cathode, bromide ions are oxidised to bromine during charge, and the reverse reaction occurs upon discharge (Reaction (2)). The electrode potentials are given vs. the standard hydrogen electrode (SHE), and the overall cell Reaction (3) possesses a potential of 1.09 V at 298 K [10–13]. 2H+ +2e− H2 0Vvs.SHE (1) 2Br− Br2 + 2e− 1.09 V vs. SHE (2) Batteries 2022, 8, 276. https://doi.org/10.3390/batteries8120276 https://www.mdpi.com/journal/batteriesPDF Image | Cathodes for the Hydrogen–Bromine Redox Flow Battery
PDF Search Title:
Cathodes for the Hydrogen–Bromine Redox Flow BatteryOriginal File Name Searched:
batteries-08-00276.pdfDIY PDF Search: Google It | Yahoo | Bing
Salgenx Redox Flow Battery Technology: Salt water flow battery technology with low cost and great energy density that can be used for power storage and thermal storage. Let us de-risk your production using our license. Our aqueous flow battery is less cost than Tesla Megapack and available faster. Redox flow battery. No membrane needed like with Vanadium, or Bromine. Salgenx flow battery
| CONTACT TEL: 608-238-6001 Email: greg@salgenx.com | RSS | AMP |