New hydrogen storage material could enable smaller, cheaper, more energy dense systems for vehicles; Kubas binding
An international team of researchers, led by Professor David Antonelli of Lancaster University, has discovered a new material made from manganese hydride that could be used to make molecular sieves within hydrogen fuel tanks.
The material—KMH-1 (Kubas Manganese Hydride-1)—demonstrates a reversible excess adsorption performance of 10.5 wt% and 197 kgH2 m−3 at 120 bar at ambient temperature with no loss of activity after 54 cycles. It could enable the design of tanks that are smaller, cheaper, more convenient and energy dense than existing hydrogen fuel technologies, and significantly out-perform battery-powered vehicles. A paper on their work is published in the journal Energy and Environmental Science.
The cost of manufacturing our material is so low, and the energy density it can store is so much higher than a lithium-ion battery, that we could see hydrogen fuel cell systems that cost five times less than lithium ion batteries as well as providing a much longer range—potentially enabling journeys up to around four or five times longer between fill-ups.—Professor Antonelli, Chair in Physical Chemistry at Lancaster University
Professor Antonelli has been researching this area for more than 15 years.
The material takes advantage of a chemical process called Kubas binding. This process enables the storage of hydrogen by distancing the hydrogen atoms within a H2 molecule and works at room temperature. This eliminates the need to split, and bind, the bonds between atoms, processes that require high energies and extremes of temperature and need complex equipment to deliver.
The KMH-1 material also absorbs and stores any excess energy so external heat and cooling is not needed. This is crucial because it means cooling and heating equipment does not need to be used in vehicles, resulting in systems with the potential to be far more efficient than existing designs.
The sieve works by absorbing hydrogen under around 120 atmospheres of pressure—less than a typical scuba tank. It then releases hydrogen from the tank into the fuel cell when the pressure is released.
The researchers’ experiments show that the material could enable the storage of four times as much hydrogen in the same volume as existing hydrogen fuel technologies. This is great for vehicle manufactures as it provides them with flexibility to design vehicles with increased range of up to four times, or allowing them to reducing the size of the tanks by up to a factor of four.
Although vehicles, including cars and heavy goods vehicles, are the most obvious application, the researchers believe there are many other applications for KMH-1.
The technology has been licensed by the University of South Wales to a spin-out company part owned by Professor Antonelli, called Kubagen.
A storage material with these properties will allow the DOE system targets for storage and delivery to be achieved, providing a practical alternative to incumbents such as 700 bar systems, which generally provide volumetric storage values of 40 kgH2 m−3 or less, while retaining advantages over batteries such as fill time and energy density. Reasonable estimates for production costs and loss of performance due to system implementation project total energy storage costs roughly 5 times cheaper than those for 700 bar tanks, potentially opening doors for increased adoption of hydrogen as an energy vector.—Morris et al.
The research was funded by Chrysler (FCA), Hydro-Quebec Research Institute, the University of South Wales, the Engineering and Physical Sciences Research Council (EPSRC), the Welsh Government and the University of Manchester.
Leah Morris, James J. Hales, Michel L. Trudeau, Peter Georgiev, Jan Peter Embs, Juergen Eckert, Nikolas Kaltsoyannis and David M. Antonelli (2019) “A manganese hydride molecular sieve for practical hydrogen storage under ambient conditions” Energy Environ. Sci., 12, 1580-1591 doi: 10.1039/C8EE02499E