Abstract
In order to efficiently operate the alkaline water electrolyzers with renewable energy, behaviors of the electrolyzer during start-up or shut-down must be unveiled, because they might be suffered by reverse current that naturally flows. The mechanism of the reverse current in alkaline water electrolyzer having relation between the electrolyzer operating conditions and cell voltage has been investigated using a bipolar-type electrolyzer which consists of two cells. The electrodes were nickel mesh, which are conventional electrodes for alkaline water electrolyzer. The amount of natural reverse current measured during off-load was proportional to the current loaded until just before stopping the operation. The increase in the charge would result from the increasing oxide on the anode of the bipolar plate. Cell voltages were above 1.4 V at all cases just when the electrolyzer is forcibly opened the circuit to stop. The major redox couple of the reverse current would be [NiO2/NiOOH] and [H2/H2O] due to the cell voltage and the redox couples. The open circuit cell voltage of the cathode terminal side cell gradually decreased to 0.3 V, while that of the anode terminal side cell was maintained above 1.1 V. Therefore, nickel oxides on the anode of the bipolar plate would be reduced, and the cathodic active material of hydrogen and nickel for the cathode side of the bipolar plate would be oxidized during the reverse current flows. Ultimately, the reverse current would stop when the redox state of both sides of the bipolar plate had the same oxidation state.
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21 December 2017
The vertical axis of Fig. 6 has been corrected.
Abbreviations
- U 1 :
-
Voltages of anode terminal cell
- U 2 :
-
Voltages of cathode terminal cell
- U 0 :
-
Theoretical decomposition voltage/electromotive force voltage
- Φ s,c,t :
-
Absolute electrostatic potential at the outside of the cathodic double layer on the cathode of the terminal
- Φ m.c,t :
-
Absolute electrostatic potential on the cathode of the terminal
- Φ s,a,t :
-
Absolute electrostatic potential at the outside of the anodic double layer on the anode of the terminal
- Φ m,a,t :
-
Absolute electrostatic potential of the anode on the anode terminal
- Φ s,c,b :
-
Absolute electrostatic potential at the outside of the cathodic double layer on the bipolar plate
- Φ m.c,b :
-
Absolute electrostatic potential on the cathode of the bipolar plate
- Φ s,a,b :
-
Absolute electrostatic potential at the outside of the anodic double layer on the anode of the bipolar plate
- Φ m,a,b :
-
Absolute electrostatic potential on the anode of the bipolar plate
- η c, η a :
-
Cathodic or anodic overpotential
- R a–c –R h–j :
-
Ionic resistance of each manifold
- I r_ac –I r_hj :
-
Measured reverse currents through each manifold
- I r :
-
Total reverse currents
- R int :
-
Internal resistance of a cell
- Q r,totl :
-
Charge of reverse current amount
- E°:
-
Standard electrode potential
References
J. Divisek, R. Jung, D. Britz, J. Appl. Electrochem. 20, 186 (1990)
Japan Soda Industry Association, Soda technology handbook (2009)
C.H. Comninellis, E. Plattner, P. Bolomey, J. Appl. Electrochem. 21, 415 (1991)
S.K. Rangarajan, V. Yegnanarayanan, Electrochim. Acta 42, 153 (1997)
R.S. Jupudi, G. Zappi, R. Bourgeois, J. Appl. Electrochem. 37, 921 (2007)
F. Xing, H. Zhang, X. Ma, J. Power Sources 196, 10753 (2011)
S. König, M.R. Suriyah, T. Leibfried, J. Power Sources 281, 272 (2015)
H. Fink, M. Remy, J. Power Sources 284, 547 (2015)
Y. Zhang, J. Zhao, P. Wang, M. Skyllas-Kazacos, B. Xiong, R. Badrinarayanan, J. Power Sources 290, 14 (2015)
R.E. White, C.W. Walton, H.S. Burney, R.N. Beaver, Journal of Electrochemical Society 133, 486 (1986)
A.T. Kuhn, J.S. Booth, J. Appl. Electrochem. 10, 233 (1980)
F. Hine, Chemical Engineering of the Alkaline Water Electrolyzer (Tokyo, CEST, 1997), pp. 47–49
A. Madono, WO 2012/03273 A1
M. Matsuoka, JP2013–209740 A
D. Britz, Digital Simulation in Electrochemistry, 1st edn. (Springer, Berlin, 1980)
E.C. Dimpault-Darcy, J. Electrochemical Society 135, 656 (1988)
P.W.T. Lu, S. Srinivasn, Journal of Electrochemical Society 125, 1416 (1978)
M. Pourbaix, Atlas of Electrochemical Equilibria (Cebelcor, Brussels, 1966), pp. 330–342
A.J. Bard, Encyclopedia of Electrochemistry of the Elements 3, 13 (1975)
Acknowledgements
This work was performed as one of the activities of alkaline water electrolysis research workshop cooperated by Asahi Kasei Co., Kawasaki Heavy Industries Ltd., ThyssenKrupp Uhde Chlorine Engineers (Japan) Ltd., De Nora Permelec Ltd., and Yokohama National University. The authors appreciate the person concerned.
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A correction to this article is available online at https://doi.org/10.1007/s12678-017-0447-x.
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Uchino, Y., Kobayashi, T., Hasegawa, S. et al. Relationship Between the Redox Reactions on a Bipolar Plate and Reverse Current After Alkaline Water Electrolysis. Electrocatalysis 9, 67–74 (2018). https://doi.org/10.1007/s12678-017-0423-5
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DOI: https://doi.org/10.1007/s12678-017-0423-5