Under the skin: the firms creating next-generation hydrogen tanks

Viritech, which revealed its 1000bhp FCEV Viritech Apricale hypercar at the Goodwood Festival of Speed last year, is focusing just as hard on hydrogen storage solutions for fuel cell vehicles as it is on fuel cell powertrains. 

Working with Haydale, a specialist in graphene-enhanced nanomaterials, it is developing a new and more efficient hydrogen storage tank. It was Haydale that helped produce the graphene-reinforced tanks for the Apricale. It also collaborated with BAC to produce graphene-enhanced bodywork parts for the BAC Mono.

In this latest meeting of minds, Haydale will be working with Viritech to develop new materials and resins. Viritech’s aim is to produce ‘type V’ pressure vessels for FCEVs and, in doing so, the pair expect to ratchet up the viability of FCEVs another notch. 

The way hydrogen pressure vessels are designed and constructed has an impact on the feasibility of fuel cell vehicles beyond merely storing the fuel. Several types (numbered I to IV) have been around for years.

The most popular solution for FCEVs is the type IV tank, which is made by wrapping a polymer liner with a carbonfibre or thermoplastic material. The liner is there to prevent the gaseous hydrogen, which can be stored at pressures of around 700 bar, seeping away. 

Type V pressure vessels have no liners. Instead, an impermeable graphene-enhanced carbonfibre material is used to make vessels that are significantly lighter than traditional types.

Haydale is no stranger to lightweight technologies. It also works in the aerospace sector and has already developed an electrically conductive carbonfibre pre-preg (carbonfibre weave impregnated with resin) designed to make aircraft resistant to lightning strikes. 

At the moment, aircraft manufacturers mould copper mesh onto the surface of carbonfibre structures, turning them into a kind of airborne lightning conductor. The company estimates around four tonnes of copper is used in the structure of a Boeing Dreamliner.

Viritech is also using its Graph-Pro technology to reduce weight. Making robust pressure vessels that can withstand anything from a major car crash to gunshots is a well-established job but not one to be sniffed at. 

Mounting tanks in vehicles of all sizes usually required frames or separate attachments, which adds further weight. The Graph-Pro structural vessels do away with all that and, says Viritech, make a considerable weight saving.

Graph-Pro technology comes in two types: fully structural and load bearing like the tanks in the Apricale, which form part of the rear bulk head; or mild structural, which have built-in mounting points and are ideal for fitting to the chassis of existing vehicle platforms without the need for additional frames.