Electronics

Proton flow battery simplifies hydrogen power

Proton flow battery simplifies...
Associate Professor John Andrews with an experimental preliminary proof of concept proton flow battery system (Photo: RMIT)
Associate Professor John Andrews with an experimental preliminary proof of concept proton flow battery system (Photo: RMIT)
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Associate Professor John Andrews with an experimental preliminary proof of concept proton flow battery system (Photo: RMIT)
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Associate Professor John Andrews with an experimental preliminary proof of concept proton flow battery system (Photo: RMIT)
The experimental preliminary proof of concept proton flow battery system that measures 65 x 65 x 9 mm (Photo: RMIT)
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The experimental preliminary proof of concept proton flow battery system that measures 65 x 65 x 9 mm (Photo: RMIT)
The conventional system for storing electrical energy as hydrogen and then regenerating electricity (Image: RMIT)
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The conventional system for storing electrical energy as hydrogen and then regenerating electricity (Image: RMIT)
The proposed new system employing a reversible fuel cell with integrated solid proton storage electrode – X represents a metal atom of the solid storage to which a hydrogen atom is bonded (Image: RMIT)
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The proposed new system employing a reversible fuel cell with integrated solid proton storage electrode – X represents a metal atom of the solid storage to which a hydrogen atom is bonded (Image: RMIT)
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Just as hydrogen fuel cell vehicles – big and small – start heading to the road, researchers at RMIT University in Melbourne, Australia, have come up with the concept of a proton flow battery that could expand the reach of hydrogen-based electrical energy systems as well as provide a potential alternative to lithium ion batteries.

Instead of conventional hydrogen-based electrical energy systems that require the production, storage and recovery of hydrogen gas, the proton flow device operates more like a battery.

Conventional systems start with an electrolyzer that splits water into oxygen and hydrogen gas, which is then stored before it is used in a fuel cell to generate electricity through the chemical reaction resulting from combining the hydrogen gas and oxygen from the air. The proton flow battery operates a little differently by integrating a metal hydride storage electrode into a reversible proton exchange membrane (PEM) fuel cell.

"The key innovation is to combine a reversible fuel cell with this integrated storage electrode," said lead researcher Associate Professor John Andrews, from RMIT's School of Aerospace, Mechanical and Manufacturing Engineering. "We've eliminated a whole step of going from protons to gas and we've got our hydrogen directly into a solid state storage."

During charging, instead of splitting water into oxygen and hydrogen and storing the resultant hydrogen gas, the concept battery would take the protons (hydrogen ions) produced when splitting water and combine them with electrons and metal particles in one electrode of a fuel cell. This stores the energy in the form a solid-state metal hydride, with electricity (and water) produced when the process is reversed and the protons are combined with oxygen from the air.

The proposed new system employing a reversible fuel cell with integrated solid proton storage electrode – X represents a metal atom of the solid storage to which a hydrogen atom is bonded (Image: RMIT)
The proposed new system employing a reversible fuel cell with integrated solid proton storage electrode – X represents a metal atom of the solid storage to which a hydrogen atom is bonded (Image: RMIT)

"As only an inflow of water is needed in charge mode – and air in discharge mode – we have called our new system the 'proton flow battery'," said Associate Professor Andrews. "Powering batteries with protons has the potential to be a much more economical device than using lithium ions, which have to be produced from relatively scarce mineral, brine or clay resources."

In principle, the researchers say the proton flow battery could have an energy efficiency comparable to a lithium ion battery, but would offer greater energy density.

"Our initial experimental results are an exciting indicator of the promise of the concept, but a lot more research and development will be necessary to take it through to practical commercial application," Associate Professor Andrews said.

The team has created an experimental preliminary proof of concept battery system that measures 65 x 65 x 9 mm (2.5 x 2.5 x 0.3 in) and published a paper on the device in the International Journal of Hydrogen Energy.

Source: RMIT, ABC Science

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10 comments
Paul Smith
So electricity is used to split water and combine the electrons and hydrogen with metal particles to form an electrode. The process is reversed when air (oxygen) is introduced to generate electricity?
Is heat generated like in a standard PEM fuel cell?
How many cycles are we looking at and how far will it take us as the only fuel carried is the electrode, and the air around us?
Grunchy
I thought Elon Musk already said that fuel cells are B.S. Didn't these guys get the memo??
SamB
This is oxidising metal to produce a current very similar to that Israeli group who have the aluminium plates as a battery thing.
It seems that it will be about 5-10 years before this type of energy storage gets some serious momentum. Good to see RMIT doing something other than being home to jaded, disinterested lecturers.
Graham Harris
Elon Musk knows everything, now?
Julie Rosenthal
Thank you for this interesting article and others like it. I am elated that top do-ers and thinkers are finding new paths to more sustainable power.
johanschaller
@Grunchy, Toyota has showcased a viable fuel cell vehicle, the FCV Concept, so I'm sure their EV partner, Musk, now knows that it isn't fanciful.
John Bailo
I don't know why people think solid storage is superior to compressed gas. For one thing, increased storage requires increased battery material that scales with volume, r^3. That's more weight to carry around.
A tank scales only with surface area, 4r^2, so it only adds the increased weight of the surface of the tank, much, much less.
Ian McIntosh
Fuel Cells are very viable - just extremely expensive and have fuel storage issues. All of this is under investigation and development. Elon Musk is producing cars using Lithium batteries because the tech for it works NOW. Fuel cells and practical fuel storage are still under development and not mass producible. Sure they can build them but not cost effectively and there remain issues still with range and robustness. Sure a fuel cell car can be refuelled, but no-one wants to stop every hour to refuel.
Esteban Sperber Frankel
What about with nickel metall hydride fuel cells instead batteries?, this proton flow battery use only water?, if yes forget it becouse goverments, oil corporations and producers will not permit such technology for mobility or electric grids, Hydrogen is the future, but when?.
Leona
Bailo Also gasoline cars need to be refuelled and they has success since early 900. This is the way, not recharge electric cars with 10000 small cell. Imagine 5 Tesla at a recharge station that need to recharge in 3 minutes like gasoline cars. How much power need that station? How much the thickness of cables? And Voltage? I wouldn't to manage a 1000V plug under rain!