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A Zinc–Bromine Flow Battery with Improved Design of Cell Structure and Electrodes
Author(s) -
Wu Maochun,
Zhao Tianshou,
Zhang Ruihan,
Jiang Haoran,
Wei Lei
Publication year - 2018
Publication title -
energy technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.91
H-Index - 44
eISSN - 2194-4296
pISSN - 2194-4288
DOI - 10.1002/ente.201700481
Subject(s) - electrode , flow battery , battery (electricity) , materials science , current density , graphite , energy storage , internal resistance , carbon fibers , bromine , nanotechnology , chemical engineering , optoelectronics , composite material , chemistry , metallurgy , composite number , power (physics) , physics , quantum mechanics , engineering , electrolyte
The zinc–bromine flow battery (ZBFB) is regarded as one of the most promising candidates for large‐scale energy storage owing to its high energy density and low cost. However, because of the large internal resistance and poor electrocatalytic activity of graphite‐ or carbon‐felt electrodes, conventional ZBFBs usually can only be operated at a relatively low current density, which limits their widespread application. Herein, we propose an asymmetrical cell by replacing the conventional thick felt electrode with a thin and electrocatalytically active carbon‐paper (CP) electrode interfacing with a flow‐field structure. With the enhanced electrocatalytic activity of CP for the Br 2 /Br − redox reaction and the reduced internal resistance of the thinner electrode, the ZBFB with this newly proposed structure exhibits an energy efficiency of up to 83.5 % at a current density of 40 mA cm −2 , much higher than that with a graphite‐felt electrode of only 73.0 %. Remarkably, the battery can even be operated at a high current density up to 100 mA cm −2 while maintaining an energy efficiency of more than 70 %, demonstrating an excellent rate capability.