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Title: Impact of membrane characteristics on the performance and cycling of the Br₂–H₂ redox flow cell

The Br₂/H₂ redox flow cell shows promise as a high-power, low-cost energy storage device. In this paper, the effect of various aspects of material selection and processing of proton exchange membranes on the operation of the Br₂/H₂ redox flow cell is determined. Membrane properties have a significant impact on the performance and efficiency of the system. In particular, there is a tradeoff between conductivity and crossover, where conductivity limits system efficiency at high current density and crossover limits efficiency at low current density. The impact of thickness, pretreatment procedure, swelling state during cell assembly, equivalent weight, membrane reinforcement, and addition of a microporous separator layer on this tradeoff is assessed. NR212 (50 μm) pretreated by soaking in 70 °C water is found to be optimal for the studied operating conditions. For this case, an energy efficiency of greater than 75% is achieved for current density up to 400 mA cm⁻², with a maximum obtainable energy efficiency of 88%. A cell with this membrane was cycled continuously for 3164 h. Membrane transport properties, including conductivity and bromine and water crossover, were found to decrease moderately upon cycling but remained higher than those for the as-received membrane.
 [1] ;  [1] ;  [1] ;  [1] ;  [2]
  1. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  2. TVN Systems, Inc., Lawrence, KS (United States)
Publication Date:
Grant/Contract Number:
AR0000262; AC02-05CH11231
Accepted Manuscript
Journal Name:
Journal of Power Sources
Additional Journal Information:
Journal Volume: 284; Journal ID: ISSN 0378-7753
Research Org:
TVN Systems, Inc., Lawrence, KS (United States)
Sponsoring Org:
USDOE Advanced Research Projects Agency - Energy (ARPA-E)
Country of Publication:
United States
25 ENERGY STORAGE; Bromine; Redox flow cell; Redox flow battery; Nafion; Membrane; Energy storage efficiency
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1360982