Contact

Dr. Xuegeng Yang

Head Electrochemical Systems
Fluid Dynamics Resource Technology Processes
x.yangAthzdr.de
Phone: +49 351 260 3863
Fax: +49 351 260 13863

Design of new-concept electrolyzer

Alkaline Water Electrolysis (AWE) is the most mature technology for producing the green hydrogen needed to transition to a net-zero emission industry. Howe­ver, AWE still lacks efficiency and operation at high current densities. Therefore, new electrolyzer designs need to be investigated to o­vercome these issues.

Goals

Membraneless electrolyzers offer advantages in terms of simplicity and cost effectiveness. In addition, these electrolyzers enable the optical access to the electrode gap. This allows for parametric studies on the multiphase flow in electrolyzers. In combination with the optimization of the electrode surfaces, the efficiency can be increased by improving the cell geometry for efficient product separation and homogeneous flow and current distribution within the cell.

Methods

  • Optical methods:

      2D PIV
      (High speed) Shadowgraphy
      Machine-learning based image segmentation

  • Electrochemical methods:

     Galvanostatic/Potentiostatic measurements
     Dissolved gas concentration (H2 and O2)

  • Other methods:

     Pressure, temperature, conductivity measurement
     GC/MS for gas purity analysis

Results

Using CFD and current simulations, an optimized Y-shaped cell geometry (see Fig. 1 (c)) was developed to ensure constant conditions for the water splitting reaction over the entire electrode. Particle Image Velocimetry and Shadowgraphy were used to systematically study the influence of the electrolyte flow as driving force for an effective H2 and O2 separation. High gas purity and overall efficiency were observed at the optimal flow rate to current density ratio.

llustration of concepts for membraneless flow-through electrolyzers designs. (a) I-shape, (b) T-shape and (c) newly proposed Y-shape.

Involved Projects

  • Solar Hydrogen (finished)
  • H2 Lab
  • ALKALIMIT

Partners

  • Chair of Fluid Mechanics, TU Dresden

  • Department of Research Technology, HZDR

Main Publication

Karl Schoppmann, Hannes Rox, Erik Frense, Frank Rüdiger, Xuegeng Yang, Kerstin Eckert, Jochen Fröhlich. WhY shape matters: Hydrodynamics of a Y-shaped membraneless electrolyzer. Submitted to Chemical Engineering Journal, 2024. DOI:10.48550/arXiv.2409.20394