TY - JOUR
T1 - Chemical and mechanical degradation of sulfonated poly(sulfone) membranes in vanadium redox flow batteries
AU - Kim, Soowhan
AU - Tighe, Timothy B.
AU - Schwenzer, Birgit
AU - Yan, Jingling
AU - Zhang, Jianlu
AU - Liu, Jun
AU - Yang, Zhenguo
AU - Hickner, Michael A.
N1 - Funding Information:
Pacific Northwest National Laboratory (PNNL) is a multiprogram laboratory operated by Battelle Memorial Institute for the Department of Energy under Contract DE-AC05-76RL01830.
Funding Information:
Acknowledgments The work is supported by the Office of Electricity (OE Delivery & Energy Reliability (OE), U.S. Department of Energy (DOE) under contract DE-AC05-76RL01830. Solvay Advanced Polymers is acknowledged for the donation of Radel polymer. The authors thank Dr. Daiwon Choi and Dr. Tak Keun Oh for SEM/EDS analyses.
PY - 2011/10
Y1 - 2011/10
N2 - A sulfonated poly(sulfone) (S-Radel®) membrane with high proton conductivity and low vanadium ion permeability showed high initial performance in a vanadium redox flow battery (VRFB) but suffered mechanical and chemical degradation during charge/discharge cycling. The S-Radel membrane showed different degradation behavior in flow cell cycling and ex-situ vanadium ion immersion tests. When the membrane was immersed in aqueous V5+ solution, the sample cracked into small pieces, but did not egrade to any measurable extent in V4+ solution. During charge/discharge cycling in the VRFB cell, the membrane underwent internal delamination, preferentially on the side of the membrane that faced the positive electrode. A vanadium-rich region was observed near the membrane surface that experienced delamination and Raman spectroscopic analysis of the degraded surface indicated a slightly depressed 1026 cm-1 band corresponding to a loss in the sulfonate SO2 stretch intensity. Even though the S-Radel membrane underwent severe mechanical damage during the flow cell cycling, significant chemical degradation was not obvious from the spectroscopic analyses. For the VRFB containing an S-Radel membrane, an increase in membrane resistance caused an abnormal voltage depression during the discharge cycle. The reversible increase in membrane resistance and severe mechanical degradation of the membrane during cycling may be attributed to repeated formation and dissolution of particles inside the membrane. The mechanical stresses imposed by the particles coupled with a small amount of chemical degradation of the polymer byV5+ ions, are likely degradation mechanisms of the S-Radel membrane in VRFBs under high state-of-charge conditions.
AB - A sulfonated poly(sulfone) (S-Radel®) membrane with high proton conductivity and low vanadium ion permeability showed high initial performance in a vanadium redox flow battery (VRFB) but suffered mechanical and chemical degradation during charge/discharge cycling. The S-Radel membrane showed different degradation behavior in flow cell cycling and ex-situ vanadium ion immersion tests. When the membrane was immersed in aqueous V5+ solution, the sample cracked into small pieces, but did not egrade to any measurable extent in V4+ solution. During charge/discharge cycling in the VRFB cell, the membrane underwent internal delamination, preferentially on the side of the membrane that faced the positive electrode. A vanadium-rich region was observed near the membrane surface that experienced delamination and Raman spectroscopic analysis of the degraded surface indicated a slightly depressed 1026 cm-1 band corresponding to a loss in the sulfonate SO2 stretch intensity. Even though the S-Radel membrane underwent severe mechanical damage during the flow cell cycling, significant chemical degradation was not obvious from the spectroscopic analyses. For the VRFB containing an S-Radel membrane, an increase in membrane resistance caused an abnormal voltage depression during the discharge cycle. The reversible increase in membrane resistance and severe mechanical degradation of the membrane during cycling may be attributed to repeated formation and dissolution of particles inside the membrane. The mechanical stresses imposed by the particles coupled with a small amount of chemical degradation of the polymer byV5+ ions, are likely degradation mechanisms of the S-Radel membrane in VRFBs under high state-of-charge conditions.
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U2 - 10.1007/s10800-011-0313-0
DO - 10.1007/s10800-011-0313-0
M3 - Article
AN - SCOPUS:83155175448
SN - 0021-891X
VL - 41
SP - 1201
EP - 1213
JO - Journal of Applied Electrochemistry
JF - Journal of Applied Electrochemistry
IS - 10
ER -