Alkaline Electrolysis with Overpotential-Reducing Current Profiles

This paper presents the relationship between electric current fluctuation and energy efficiency of a laboratory scale alkaline electrolyzer, combined with a novel rectifier system. Electrochemical impedance spectroscopy of the electrolysis cell provides information on the ohmic resistances, the doub...

Full description

Saved in:
Bibliographic Details
Published in:ECS transactions 2018-01, Vol.83 (1), p.179-194
Main Authors: Speckmann, Friedrich Wilhelm, Bintz, Steffen, Groninger, Max Lucas, Birke, Kai Peter
Format: Article
Language:English
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:This paper presents the relationship between electric current fluctuation and energy efficiency of a laboratory scale alkaline electrolyzer, combined with a novel rectifier system. Electrochemical impedance spectroscopy of the electrolysis cell provides information on the ohmic resistances, the double layer capacity between electrodes and the electrolyte as well as the frequency dependency of these parameters. Thus, it enables the generation of specific current profiles in order to reduce ohmic resistance from polarization as well as bubble evolution. The measurement results show a connection of the energy efficiency on the provided current profiles as well as on the periodical pulse duration. A pulsed current profile, based on the results from the impedance spectroscopy, is able to reduce polarization and bubble resistance losses, while consuming additional electrical energy.
ISSN:1938-5862
1938-6737
1938-6737
1938-5862
DOI:10.1149/08301.0179ecst