scholarly journals Corrected accelerated service life test of electrodeposited NiSn alloys and Ni as cathodes for industrial alkaline water electrolysis

2019 ◽  
Vol 84 (11) ◽  
pp. 1271-1286
Author(s):  
Vladimir Jovic ◽  
Borka Jovic ◽  
Nevenka Elezovic ◽  
Ljiljana Gajic-Krstajic
Keyword(s):  
Cyclic Voltammetry ◽  
Service Life ◽  
Electrode Materials ◽  
Water Electrolysis ◽  
Alloy Coating ◽  
Separate Experiment ◽  
Life Test ◽  
Alkaline Water Electrolysis ◽  
Polarity Inversion ◽  
Alkaline Water

The ?corrected accelerated service life test for hydrogen evolution reaction? (CASLT-HER), designed for application of certain electrode materials as cathodes in the cell for alkaline water electrolysis in 30 % KOH at 80 ?C, was performed at electrodeposited NiSn alloy and Ni 40 mesh electrodes. The Ni 40 mesh was slightly etched, while the NiSn alloy coating was electrodeposited from the bath containing pyrophosphate, glycine, SnCl2 and NiCl2 onto Ni 40 mesh to the thickness of approximately 40 ?m. It is shown that the NiSn cathode possess from maximum 0.77 V to minimum 0.30 V better overpotential than the Ni 40 mesh electrode during the 5 years of their exploitation at the conditions of industrial alkaline water electrolysis. It is also shown that both electrodes should be held at j = ?0.3 A cm-2 for at least 5 h in order to establish stable overpotential response. The limiting overpotential values for applying cyclic voltammetry (CVs, to mimic ?polarity inversion?) should be determined in a separate experiment before the CASLT-HER and should be adjusted during the application of CVs.

Preparation and Characterization of Nickel and Copper Oxide/Hydroxide Films on Stainless Steels Substrates for Use as Cathodes in Alkaline Water Electrolysis

2015 ◽  
Vol 772 ◽  
pp. 55-61
Author(s):  
David S.P.P. Cardoso ◽  
Paulo S.D. Brito ◽  
Luiz F.F.T.T.G. Rodrigues
Keyword(s):  
Stainless Steel ◽  
Copper Oxide ◽  
Electrode Materials ◽  
Water Electrolysis ◽  
304 Stainless Steel ◽  
Alkaline Water Electrolysis ◽  
Alkaline Water ◽  
Good Electrocatalytic Activity ◽  
High Specific Energy ◽  
Oxide Composites

The production high purity hydrogen by water electrolysis based renewable sources as a mean to store energy, has gained some attention in the last years due to the high specific energy of hydrogen, the potentially neutral carbon and zero emission of the usage of H2as fuel. However, it remains certainly necessary to develop efficient and lower cost electrolyzers. Such a situation requires the search for and the development of inexpensive and stable electrode materials, showing low polarization to hydrogen evolution reduction (HER). In this work copper and nickel oxides were studied for use as electrodes for the reduction of hydrogen in alkaline water electrolysis. The nickel and copper oxide composites coatings were deposited electrochemically as oxides/hydroxides on a stainless steel (SS) electrode and characterized using electrochemical methods such as cyclic voltammetry (CV), cathodic polarization and Tafel slops. The HER was studied using as electrolytic cathodes unmodified AISI 304 stainless steel (SS), nickel coated stainless steel (SS/Ni), copper coated stainless steel (SS/Cu), and nickel (under layer) and copper (top layer) coated stainless steel (SS/Ni/Cu) in 5 M KOH solution. It was found that, the SS/Ni/Cu electrode presents good electrocatalytic activity and stability toward the HER, compared to the SS electrodes modified by single nickel oxide layer. This behavior seems be explained by the synergistic interaction of Ni and Cu with Fe present in the stainless steel.

Modelling and control of an alkaline water electrolysis process

2018 ◽  
Vol 1 (2) ◽  
pp. 9-14
Author(s):  
Marisol Cervantes-Bobadilla ◽  
Ricardo Fabricio Escobar Jiménez ◽  
José Francisco Gómez Aguilar ◽  
Tomas Emmanuel Higareda Pliego ◽  
Alberto Armando Alvares Gallegos
Keyword(s):  
Process Model ◽  
Water Electrolysis ◽  
Alkaline Water Electrolysis ◽  
Alkaline Water ◽  
Electrolysis Process ◽  
Linear Dynamic ◽  
Energy Current ◽  
Identification Technique ◽  
Nonlinear Static ◽  
And Control

In this research, an alkaline water electrolysis process is modelled. The electrochemical electrolysis is carried out in an electrolyzer composed of 12 series-connected steel cells with a solution 30% wt of potassium hydroxide. The electrolysis process model was developed using a nonlinear identification technique based on the Hammerstein structure. This structure consists of a nonlinear static block and a linear dynamic block. In this work, the nonlinear static function is modelled by a polynomial approximation equation, and the linear dynamic is modelled using the ARX structure. To control the current feed to the electrolyzer an unconstraint predictive controller was implemented, once the unconstrained MPC was simulated, some restrictions are proposed to design a constrained MPC (CMPC). The CMPC aim is to reduce the electrolyzer's energy consumption (power supply current). Simulation results showed the advantages of using the CMPC since the energy (current) overshoots are avoided.

scholarly journals Boosting alkaline water electrolysis by asymmetric temperature modulation

2021 ◽  
Vol 119 (1) ◽  
pp. 013901
Author(s):  
Qinpeng Zhu ◽  
Peihua Yang ◽  
Tao Zhang ◽  
Zehua Yu ◽  
Kang Liu ◽  
...  
Keyword(s):  
Water Electrolysis ◽  
Temperature Modulation ◽  
Alkaline Water Electrolysis ◽  
Alkaline Water

scholarly journals Towards the Hydrogen Economy—A Review of the Parameters That Influence the Efficiency of Alkaline Water Electrolyzers

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3193
Author(s):  
Ana L. Santos ◽  
Maria-João Cebola ◽  
Diogo M. F. Santos
Keyword(s):  
Energy Content ◽  
Water Electrolysis ◽  
High Energy ◽  
Operating Conditions ◽  
Energy Sources ◽  
Alkaline Water Electrolysis ◽  
Alkaline Water ◽  
New Energy ◽  
Recent Developments ◽  
Cell Components

Environmental issues make the quest for better and cleaner energy sources a priority. Worldwide, researchers and companies are continuously working on this matter, taking one of two approaches: either finding new energy sources or improving the efficiency of existing ones. Hydrogen is a well-known energy carrier due to its high energy content, but a somewhat elusive one for being a gas with low molecular weight. This review examines the current electrolysis processes for obtaining hydrogen, with an emphasis on alkaline water electrolysis. This process is far from being new, but research shows that there is still plenty of room for improvement. The efficiency of an electrolyzer mainly relates to the overpotential and resistances in the cell. This work shows that the path to better electrolyzer efficiency is through the optimization of the cell components and operating conditions. Following a brief introduction to the thermodynamics and kinetics of water electrolysis, the most recent developments on several parameters (e.g., electrocatalysts, electrolyte composition, separator, interelectrode distance) are highlighted.

scholarly journals Electrode-diaphragm assembly for alkaline water electrolysis

2020 ◽  
Vol 1683 ◽  
pp. 052011
Author(s):  
V N Kuleshov ◽  
S V Kurochkin ◽  
N V Kuleshov ◽  
D V Blinov ◽  
O Y Grigorieva
Keyword(s):  
Water Electrolysis ◽  
Alkaline Water Electrolysis ◽  
Alkaline Water
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