Boosting electrode performance and bubble management via Direct Laser Interference Patterning

TL;DR

This study demonstrates that Direct Laser Interference Patterning significantly enhances Ni electrode performance for water electrolysis by increasing active surface area and improving bubble management, leading to lower overpotentials and resistance.

Contribution

The paper provides a systematic experimental analysis of how laser-structuring parameters affect electrode performance, introducing optimized laser patterning for better electrolysis efficiency.

Findings

Active surface area increased by a factor of 12.

Lower onset potential and overpotential for oxygen evolution.

Spatial distance between laser structures is critical for performance improvement.

Abstract

Laser-structuring techniques like Direct Laser Interference Patterning show great potential for optimizing electrodes for water electrolysis. Therefore, a systematic experimental study based on statistical design of experiments is performed to analyze the influence of the spatial period and the aspect ratio between spatial period and structure depth on the electrode performance for pure Ni electrodes. The electrochemically active surface area could be increased by a factor of 12 compared to a non-structured electrode. For oxygen evolution reaction, a significantly lower onset potential and overpotential ($\approx$-164 mV at 100 mA/cm$^2$) is found. This is explained by a lower number of active nucleation sites and, simultaneously, larger detached bubbles, resulting in reduced electrode blocking and thus, lower ohmic resistance. It is found that the spatial distance between the laser-structures is the decisive processing parameter for the improvement of the electrode performance.