High-efficient electrodes for alkaline electrolysis based on electroplating combined with pulsed laser ablation and ex situ sulfiding.

The purpose of the project is to develop, demonstrate and qualify the use of Pulsed Laser Deposition (PLD) technology combined with ex situ sulfiding process to improve the characteristics and performance of standard nickel foam electrodes. This could be a game changer concerning state-of-the-art electrolyser technology for low-cost green hydrogen production. Applying Pulsed Laser Deposition (PLD) technology for the coating may potentially improve the electrode performance in two pathways: (i) by increasing the surface area and thereby increasing the number of active surface sites and (ii) altering the performance of the intrinsic properties of the surface sites lowering the overpotential for hydrogen and oxygen formation. In both cases, the hydrogen production will become more energy efficient producing more hydrogen at a lower voltage. Thereto comes the possibility of combing the PLD technology with ex situ sulfiding. Initial lab-scale tests at ASP have indicated that the ex situ sulfiding process may potentially replace electroplating processes and it may actually be possible to obtain highly active electrodes (and get the same high-performing electrodes) by using ex situ H2S sulfidation instead of electroplating processes. Overall, these processes will potentially increase both the surface area and the performance of the hydrogen producing surface sites – both are expected to increase the electrolyser efficiency. Additionally, the lifetime of the highly efficient electrodes is expected to increase due to the good coating adhesion obtainable by Pulsed Laser Deposition (PLD)

The aim of this project is to enhance the efficiency of alkaline electrolysis by improving two specific characteristics of the involved nickel foam electrodes. Firstly, by increasing the nickel surface area, and secondly, by modifying the surface sites to decrease the overpotential for hydrogen and oxygen formation. The development will utilise electroplating, Pulsed Laser Deposition (PLD) techniques combined with ex situ sulfiding with the aim of reducing OPEX for hydrogen formation by 4-6% (beyond the already achieved reduction of 12-14% obtained by Advanced Surface Plating (ASP)) to produce green hydrogen. Only by combining the already achieved efficiency improvement with this new invention, HPRO will get the total electrolyser efficiency improvement decreasing from 4.4 kWh/Nm3 to approximately 3.7 kWh/Nm3 and thereby create the most efficient alkaline electrolyser globally. Additionally, the PLD production opportunity combined coablation of Ni/Mo with ex situ sulfiding, will make the fundament for highly efficient large-scale rollto-roll electrode production 10-15 times more efficient than the existing electroplating batch production. A new production setup with PLD will also eliminate the wet chemistry in electrode production and reduce the electrode unit cost significantly. Furthermore, it is the aim to increase the electrode’s lifetime by 30-50% compared to standard electrodes due to a significantly better coating adhesion to be obtained by the high energetic irons achieved by the PLD technique. Today, the degradation of standard electrodes is 0.13% per 1,000 production hours (based on information from customers) and the target for this project is to lower the degradation to 0.09% per 1,000 production hours which is realistic. Additionally, since the electrodes also have higher efficiency and the degradation will be lower, it is the expectation that customers will keep the electrodes for at least 10 years before substitution/or in situ upgrading