Construction and Characterization of the Membrane Alkaline Water Electrolysis Stack

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60461373%3A22310%2F19%3A43918238" target="_blank" >RIV/60461373:22310/19:43918238 - isvavai.cz</a>

Result on the web

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DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Construction and Characterization of the Membrane Alkaline Water Electrolysis Stack

Original language description

The flexible operating water electrolysers with low investment and operating cost are required to launch future hydrogen economy. Membrane alkaline water electrolysis (MAWE) represents new trend in water electrolysis. Main advantages are represented by: use of non platinum group metal catalysts, substitution of an inorganic diaphragm with a membrane enables achieving higher current densities, higher gas purities and asymmetric pressure operation. In this work, we constructed and characterized a MAWE stack consisting of three cells with nickel foam electrodes and nickel sheet current collectors. The anion-selective membranes were made of poly(styrene ethylene butylene-styrene) functionalized by 1,4-diazabicyclo[2.2.2]octane (DABCO)1. The active area of each electrode and membrane was 78,5 cm2. Potassium hydroxide was used as the electrolyte in different concentrations up to 15% wt. The operating temperature of the stack was kept under 50°C to ensure time stability. As for the characterization methods, linear sweep voltammetry was used to obtain the load curves and performance characterization. The current efficiency was evaluated based on produced gas flow rate measurement. Given these results, energy efficiency was calculated. Electrochemical impedance spectroscopy was used to determine the resistance of the stack and gas chromatography was used to find out the gas purities under different operational conditions. Gas purities depend mostly on the efficiency of used gas separators if anion selective membrane is used. With the rising electrolyte concentration, the stack performance improved due to the higher conductivity. Nevertheless, while remaining required characteristics, anion-selective membranes enabled using lower electrolyte concentration (e.g. 10 wt.% KOH) instead of highly concentrated (25-30 wt.% KOH) electrolyte commonly used in the industry. This also decreases the amount of parasitic currents by lowering the conductivity. Based on obtained results further extension of stack up to the capacity 250L/h is possible. Moreover the modification of nickel foam electrodes by suitable catalyst will decrease stack energy consumption.

Czech name

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Czech description

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Type

O - Miscellaneous

CEP classification

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OECD FORD branch

10405 - Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis)

Project

<a href="/en/project/FV10529" target="_blank" >FV10529: Advanced process for electrolytic hydrogen production from renewable sources</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2019

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů