Power paste - a new way of storing energy
The biggest problem with hydrogen storage seems to be solved
Researchers at the Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM in Dresden have come up with a hydrogen-based fuel - Powerpaste, which is based on solid magnesium hydride.
Hydrogen in the form of a paste could power tomorrow's equipment. The paste mixes hydrogen with magnesium and additives to form a smooth paste. Paste cartridges can power devices
"Powerpaste stores hydrogen in chemical form at room temperature and atmospheric pressure so that it can be released as needed," explains Dr. Marcus Vogt, researcher at Fraunhofer IFAM. And as Powerpaste only begins to decompose at temperatures around 250 ° C, it remains safe even when the e-scooter stands in the sun for hours. In addition, refueling is extremely easy. Instead of the riders going to the gas station, they just have to replace the empty cartridge with a new one and then refill the main tank with water.
The starting material of Powerpaste is magnesium, one of the most abundant elements, and therefore an easily available raw material. On board the vehicle, the Powerpaste is released from the cartridge by means of a piston. When water is added from the onboard tank, the subsequent reaction generates hydrogen gas in an amount dynamically adjusted according to the actual requirements of the fuel cell. In fact, only half of the hydrogen comes from Powerpaste; the rest comes from added water.
"So Powerpaste has a huge energy storage density," says Vogt. "It is significantly higher than with a high-pressure tank with a pressure of 700 bar. And compared to batteries, it has a density ten times higher than energy storage. “This means that Powerpaste offers a range comparable to petrol or even larger. It also provides a higher range than compressed hydrogen at a pressure of 700 bar.
Suitable for electronic scooters - and also for other applications
Due to its high energy storage density, POWERPASTE is also an interesting choice for cars, vans and range-extenders in battery-powered electric vehicles. Similarly, it could significantly extend the flight time of large drones, which would be able to fly for several hours rather than only 20 minutes. This would be particularly useful for exploration work such as forest inspections or power lines. In another type of application, campers may also use Powerpaste in a fuel cell to generate electricity to power a coffee machine or toaster.
Powerpaste helps overcome the lack of infrastructure
In addition to providing a high operating range, Powerpaste has other benefits. Unlike hydrogen gas, it does not require expensive infrastructure. This makes it ideal for areas without such infrastructure. Therefore, in places where there are no hydrogen stations, conventional gas stations could sell Powerpaste in cartridges or canisters instead. The paste is liquid and pumpable. It can therefore be supplied by a standard filling line using relatively inexpensive equipment. Initially, gas stations were able to supply smaller amounts of Powerpaste - for example from a metal drum - and then expand according to demand. Powerpaste is also cheap to transport because there are no expensive high-pressure tanks or the use of extremely cold liquid hydrogen.
The pilot center is planned for 2021
Fraunhofer IFAM is currently building a production plant for Powerpaste in the Fraunhofer Project Center for Energy Storage and ZESS Systems. Commissioning is scheduled for 2021 and will be able to produce up to four tons of Powerpaste per year.
Powerpaste is a magnesium and hydrogen -based fluid gel that releases hydrogen when it reacts with water. It was invented, patented and is being developed by Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM) of the Fraunhofer-Gesellschaft in Dresden, Germany.
Powerpaste is made by combining magnesium powder with hydrogen in a process conducted at 350 °C and five to six times atmospheric pressure to form magnesium hydride. An ester and a metal salt are then added to make the finished Powerpaste.
When Powerpaste reacts with water it produces hydrogen in a predictable manner for use in fuel cells. The molecular formula of magnesium hydride reacting with water is MgH2 + 2H2O → 2H2 + Mg(OH)2, so half of the produced hydrogen comes from the Powerpaste and half from the water. Magnesium hydroxide (Mg(OH)2) is a residue by-product created by this process.
Fraunhofer claims that Powerpaste is able to store hydrogen energy at 10 times the energy density of a lithium battery of a similar dimension and substantially more than compressed hydrogen at 700 bar and is safe and convenient for automotive situations. 
Fraunhofer states that they are building a production plant slated to start production in 2021, which will produce 4 tons of Powerpaste annually. Fraunhofer has patented their invention in the USA and EU.
- Röntzsch, Lars; Vogt, Marcus (February 2019). White paper - PowerPaste for off-grid power supply (Technical report). Fraunhofer Society.
- "Hydrogen-powered drives for e-scooters" (Press release). Fraunhofer Society. 2021-02-01. Retrieved 2021-02-22.