Oxford nanoSystems Ltd (OnS) is a high-tech start-up that spent the past 6 years developing nanoFLUX -- a nano-coating which dramatically improves the efficiency of two-phase heat-exchangers, such as evaporators. Our core technology, nanoFLUX is a highly-porous coating that enhances evaporative heat transfer by significantly increasing the density of nucleation sites on a surface. Unlike mechanical and sintered enhancements, nanoFLUX can be applied to internal surfaces and intricate micro-scale structures.

Looking towards future applications, we acknowledge the UK's drive for sustainable energy. There is a growing demand for electrolysers that produce green hydrogen for energy storage. From the existing electrolysis methods are two of interest: PEM and alkaline electrolysers (AWE). PEM electrolysers have certain advantages including compact size, the ability to deal with a variable/intermittent renewable power source and the purity/ pressure of the hydrogen generated. However, PEM electrolysers require expensive noble metal catalysts at the electrodes. Alkaline electrolysers use lower-cost materials (e.g. nickel electrodes) and can offer the potential to process saline water. The downside is the efficiency and performance are less than the PEM electrolysers. OnS will focus on AWE, because it is the most mature technology and we believe our technology is able to substantially improve the efficiency of the process.

In this project we will use a hierarchical structure including nanoFLUX to enhance the cathode electrode. This will reduce the reaction overpotential by enhancing bubble nucleation and release of hydrogen. As a result, more electrolysis reactions are possible and the efficiency of the whole system will be greatly enhanced. Currently there are no technologies on the market that can offer a low cost, easy applicable solution.

We need to quantify nanoFLUX performance in AWE hydrogen bubble formation in comparison to uncoated or SotA samples. To achieve this, NPL will design a flow cell test rig and provide independent measurements. This will enable OnS to offer our coating service to electrolyser manufacturers and thus providing the company with an additional revenue stream.

The output of the project will be a report detailing the performance and accelerated lifetime testing on the coating material in AWE application. A further output will be a new test rig at NPL to allow testing of hydrogen bubble formation, and know-how in surface area measurements of coatings on substrates. This will allow NPL to expand the range of services it can offer.