Nanomaterials advance hydrogen storage for fuel cells

The collaboration between Viritech, a developer of high-performance hydrogen powertrain solutions for the automotive industry, and Haydale, a specialist in graphene-enhanced nanomaterials, could help create new materials for ‘Type 5’ hydrogen storage tanks, providing a significant market opportunity that could help speed the adoption of hydrogen powered fuel cell powertrains, initially in commercial vehicles.

Viritech CEO Timothy Lyons said the company was “delighted to be extending our partnership with Haydale”.

“With hydrogen’s growing emergence as a key pillar in the road to sustainable transportation, vehicle manufacturers are starting to design their first series-production fuel cell vehicles, and working together, our two companies are ideally placed to capitalise on one of the most important growth markets of the next two decades.”

Beyond merely holding the fuel, the design and construction of hydrogen tanks affects the viability of fuel cell electric vehicles (FCEVs).

There are a few different types, including all-metal tanks (Type 1), composite tanks with metal hoop wrappings (Type 2), composite tanks with metal linings (Type 3), and composite tanks with plastic linings (Type 4).

‘Type 4’ tanks are heavy; they are constructed by encasing a polymer liner in a carbon-fibre or thermoplastic material, yet they are still the most suitable FCEV solution. The liner’s purpose is to stop the gaseous hydrogen from escaping while being kept at pressures of up to 700 bar.

As a result their weight efficiency is about five per cent, meaning that 5 kg of hydrogen, which can power a family car for about 480km, needs a tank that weighs about 100 kg.

‘Type 5’ tanks do away with the need for liners, making them 20 per cent lighter. They have been the Holy Grail of the pressure vessel business for years and are made from an impermeable carbon -fibre that has been strengthened with graphene nanomaterial.

In addition, Viritech will also keep developing its Graph-Pro structural pressure tanks, which include mounting points that bolt directly to a vehicle’s chassis, eliminating any need for extra frames or attachments. As a result, pressure tank installation is simplified and further weight is saved.

There are two types of Graph-Pro technology: ‘mild structural’, which has built-in mounting points and is ideal for mounting to the chassis of existing vehicle platforms without the need for additional frames, and ‘fully structural’, which incorporates the tanks as a load-bearing and integral part of the chassis.

The focus for Viritech and Haydale, however, will be the development of tanks for commercial vehicles. 

At this early stage of hydrogen uptake, these vehicles will require the  biggest production numbers, although hydrogen fuel cell passenger vehicles and SUVs will also benefit from the same ‘Type 5’ tank technology.