The hydrogen based Powerpaste is being developed as a possible fuel option for small vehicles such as electric scooters and motorcycles.
Hydrogen fuel cell vehicles are fast emerging as an alternative to battery electric vehicles. But hydrogen is not yet an option for small vehicles such as electric scooters and motorbikes due to the requirement for a reinforced tank to withstand the 700 bar pressure surge during refuelling.
A possible solution emerging is the hydrogen-based paste, named the Powerpaste, which is being developed at the Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM in Dresden.
The paste is made out of magnesium, which is combined with hydrogen to form magnesium hydride in a process conducted at 350oC and five to six times atmospheric pressure. The finished paste is stored in a cartridge and on a vehicle it can be released by means of a plunger and mixed with water from an onboard tank to generate the hydrogen gas required for the vehicle fuel cell.
The process appears to be efficient with about half the required hydrogen content coming from the Powerpaste and half from the water.
Moreover, it has the prospect of being both simple and safe to use. Refuelling is a matter of replacing an empty cartridge with a new one and refilling a tank with water. And as the Powerpaste begins to decompose at around 250oC, the vehicle can undergo extended use in the sunniest conditions.
“Powerpaste stores hydrogen in a chemical form at room temperature and atmospheric pressure to be then released on demand,” explains Dr. Marcus Vogt, research associate at Fraunhofer IFAM.
“Powerpaste has a huge energy storage density, substantially higher than that of a 700 bar high pressure tank. And compared to batteries, it has ten times the energy storage density. This means that Powerpaste offers a range comparable to, or even greater than, gasoline.”
In addition to two wheeled vehicles, the Powerpaste could provide an option for cars, delivery vehicles and range extenders in battery-powered electric vehicles. It also could find use in applications as diverse as large drone range extension or for energy requirements for campers.
With no need for a substantial delivery infrastructure, the Powerpaste also could be of interest for use in rural areas.
Fraunhofer IFAM is currently building a production plant for Powerpaste at the Fraunhofer Project Center for Energy Storage and Systems ZESS at Braunschweig in northcentral Germany with an ouput of up to four tons per year.