HYDRA
High-throughput hydrogen production through dry-cathode alkaline electrolysis.
Introduction
Green hydrogen is widely recognised to play a pivotal role in the energy transition. Unfortunately, the cost of electrolytic green hydrogen is a major hurdle for its widespread adoption. The OPEX cost is mainly associated with the electricity consumption, hence increasing the efficiency is key. The CAPEX is determined by the cost of the electrolyser system, its lifetime and throughput. HYDRA sets out to drastically improve both parameters by using a catholyte-free or dry cathode approach.
Goal
The goal of this project is to move dry cathode alkaline electrolysis closer to industrial application. To accomplish this, we aim to scale up the cell area, demonstrate stackability, and optimize cell voltage. Imec will leverage its expertise in nanostructured electrode manufacturing, electrochemical characterization, and ionic transport. VITO will contribute with its experience in cell and stack design, system-level know-how, and techno-economic analysis (TEA).
Concrete objectives are:
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Optimisation of the catalytic Ni nanomesh electrodes for dry cathode operation and upscaling to minimally 200 cm²
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Optimisation of the anolyte chemistry, concentration and diaphragm properties
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Proof of concept electrolysis cell at minimum 200 cm², stable operation for 200 hours at a cell potential below 1.85 V at 1 A/cm² and below 2.4 V at 5 A/cm².
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Proof of concept electrolysis stack of at least 5 kW.
Approach
The idea is to develop an innovative dry cathode electrolysis cell stack that merges the benefits of both AWE and anion exchange membrane (AEM) electrolyzers. This new cell stack will utilize the proven membrane stability and system robustness of AWE, along with the high throughput, efficient nanostructured electrodes, and low shunt currents characteristic of AEM electrolyzers.
To accomplish this, we will operate the cathode in a dry state within the electrolysis cell, employing a robust separator and the ultra-thin nanomesh electrodes developed at imec. Proof-of-principle experiments at imec and VITO (4 cm²) have demonstrated that the dry cathode system achieves current densities in excess of 6 A/cm² without encountering any mass transport limitations. This throughput significantly surpasses the operating regimes of both AWE (0.2-0.8 A/cm²) and AEM electrolyzers (0.2-1 A/cm2).
Expected impact and valorization
The chemical, steel and refinery sectors are crucial sectors for the Flemish economy and employment but alas are also responsible for 30% of the total greenhouse gas emissions. Low-cost green hydrogen is crucial for these hard-to-abate sectors to remain competitive while meeting their environmental targets. But the Flemish industry is not only an end-user of renewable hydrogen, it is also well positioned to deploy it worldwide, as it is home to component, system and renewable energy project developers. The HYDRA projects benefits that entire value chain.
Project details
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