Abstract
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 Br2/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.
Original language | English |
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Pages (from-to) | 333-339 |
Number of pages | 7 |
Journal | Energy Technology |
Volume | 6 |
Issue number | 2 |
DOIs | |
Publication status | Published - Feb 2018 |
Externally published | Yes |
Keywords
- carbon paper
- electrodes
- energy storage
- flow batteries
- power density
ASJC Scopus subject areas
- General Energy