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Journal of Thermal Spray Technology

, Volume 4, Issue 2, pp 185–194 | Cite as

Vacuum plasma spraying of high-performance electrodes for alkaline water electrolysis

  • G. Schiller
  • R. Henne
  • V. Borck
Reviewed Papers

Abstract

Electrode coatings for advanced alkaline water electrolysis were produced by applying the vacuum plasma spraying (VPS) process. The characteristics of the used VPS equipment that were essential for the development of effective electrocatalytic electrode layers are presented. Molybdenum-containing Raney nickel coatings were applied for cathodic hydrogen evolution, and Raney nickel/Co3O4 matrix composite layers were developed for the anodic oxygen evolution reaction. For the preparation of Raney nickel coatings, a precursor alloy such as Ni-Al was sprayed that had to be leached subsequently in caustic solution to remove the aluminum content, forming a porous, high-surface-area nickel layer. The spray powders and the resulting VPS layers were studied by metallography, x-ray diffraction (XRD), and scanning electron microscopy/energy dispersive analysis by x-ray (SEM/EDX). For spraying of thermally sensitive oxide electrocatalysts (e.g., Co3O4), special process conditions involving plasma-chemical effects (reactive plasma spraying) had to be developed. The electrocatalytic activity of the electrode coatings was investigated by performing polarization curves free of ohmic losses (IR-free) and long-term tests under conditions of continuous and intermittent operation, which showed excellent electrochemical properties.

Keywords

cobalt oxide feedstock feedstock phase changes oxide electrocatalyst Raney nickel coatings vacuum plasma spraying water electrolysis 

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Copyright information

© ASM International 1995

Authors and Affiliations

  • G. Schiller
    • 1
  • R. Henne
    • 1
  • V. Borck
    • 1
  1. 1.Deutsche Forschungsanstalt für Luft- und Raumfahrt (DLR)Institute of Technical ThermodynamicsStuttgartGermany

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