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19 May 2022

Thin-film hydrogen storage at scale from Plasma Kinetics

We interviewed a truly original company this week called Plasma Kinetics, run by a husband and wife team, Paul and Stacey Smith, which claims to have developed a unique method for bonding hydrogen both for storage and release within applications, by adsorption onto a Magnesium hydride thin film layer.

The idea is not new, and if you look at a variety of published papers on the internet you can see that this has been a topic of fierce debate for well over a decade, with the stumbling blocks usually being the huge amount of energy required to release hydrogen from such an adsorption layer.

This is a company founded in 2008, that has had a variety of difficulties bring the technology to market – US government security agencies initially discouraged them from doing so, and then in 2017, as the US market showed little interest in hydrogen, the company was laid to rest.

Now it has come back to life and over the past year it has popped up in interviews across the energy segment – with a combination of reactions – from “wow, this is incredible”  to “yeah sure, I don’t believe you.”

I confess that I believed the pitch hook line and sinker and if it turns out that after all this idea is an out of date April fools joke, then someone smarter than me with a lot better physics can call me and tell me where I went wrong.

So here’s the idea in a nutshell. The system uses the same equipment that many semiconductor processes use, vapor deposition of layer after layer of materials forming a series of surfaces that get the job of capturing and storing hydrogen handled efficiently and safely.

In all there are around 4,000 layers, but conceptually there are 7 material layers, some measured in Ångström units, others in nanometers, as well as elongated dendrites of Magnesium Hydride to give it a huge potential surface area.

The first layer is what Smith calls a “non-flammability” layer so that the hydrogen cannot be set on fire – he does not explain how that works; the next enables some ferroelectric tunneling, for moving charge through the layers;  the next is to provide plasmonic movement of the surface structure – to create resonance between conducted electrons and photons to create stability in the magnesium hydrogen bonds, and finally a ferroelastic or shape memory alloy.

This effectively changes the shape of the material by moving it from one stable crystal structure to another, and when this is triggered the hydrogen bond is significantly weakened for release. This change is created by the simple expedient of shining specific wavelengths of light at the surface.

So how does this work? Well first the surface is an incredibly thin magnesium core, then with these layers it is negatively charged and attracts hydrogen atoms. Smith says that this happens in 1/34th of a second, and runs the surface through on a film, literally like a rapidly turning spindle, like a tape player. Playing it back the other way and shining a laser onto the surface releases the hydrogen.

Each of these pieces of film are arranged in canisters, just like computer tape, and each canister can consume and bond with 17 kilograms of hydrogen. 70 such containers can fit into a 20 foot shipping container, which stores 1,000 kg of hydrogen. There is no freezing down to minus 250°C, no requirement to store the hydrogen at up to 700 bar, and yet the container space is roughly the same size as 1000 kg of frozen hydrogen would be, and yet you have saved all the energy of either freezing or pressurizing (both), and have managed to store it in such a way that it is safe to transport.

“A lot of municipalities are banning the transport of hydrogen containers or trucks which use frozen hydrogen for the fuel in a fuel cell, because they are worried that they are not safe,” says Smith. We tried to set one of our prototypes on fire with a blow torch, and we managed to get it to smolder after a while, but it would not catch fire,” he said.

There is a problem which has led to Smith’s view on the right business model – the system is only good for capturing and storing hydrogen about 150 times. After that tiny flakes of the magnesium tape start to fall away, and it develops cracks, and slowly it loses capacity.

Which is why the business model is about selling re-charge cycles, not equipment. The new business plan is to sell a set number of re-charges, and then to replace each canister with a new one. The old one though has a hidden benefit.

“The light releases only the most common isotope of hydrogen Protium, and over time Deuterium, the second most frequent isotope starts to build up – it is never more than 1%, but it stays bonded to the magnesium. We can recover this and all the materials, and recycle them to make another canister, and sell the Deuterium for industrial purposes.” The money they get pays for 100% of the recycling costs of the unit, Smith claims.

Sure but that’s can’t really happen once the process is at scale. Or can it? “We calculated that at scale this would double the amount of Deuterium in circulation, but we could even harness it to power our factory, so we’re not worried about that not being of any use.”

So the entire business model hinges on this, free cost of re-cycling, means that the 150 re-charge limit can be thought of as unlimited re-charges, and a return to base “Canister” replacement business becomes the model, a little like CATL has built a replacement battery market for EVs in China.

But there are significant issues – the business is not that developed, it has just re-opened after 3 years of being shuttered, and most of the potential customers are not in the US. We picked up on one comment when Smith said he could ship on 5 continents – the two he cannot ship on are Antarctica and much of Asia – but in particular neither China nor Russia. That’s because this technology still has significant potential benefits for an unfriendly country.

The image we see in this article is the envisaged canister CAD drawings, and the prototypes are only hand-made and just large enough to power a light source. When we raised this as an issue, Smith said “Yes, but we had all the equipment, we had scaled up in 2017, and then we sold it all – we know precisely how this is done, and whether it works.”

He sees the canisters used to power trucks directly, releasing hydrogen into a fuel cell, but will have to first find $20 million to build a pilot production plant and iron out the kinks in the manufacturing process, then another $100 million to scale that, and offer a demonstrator hub where customers will be able to work out if they can use the storage method in the right format at the right price for their application. Finally to have manufacture on 3 continents, it will cost another $200 million.

Then he said something ominous, “But we already have a backlog of orders which more than supports that spend,” implying that $320 million of costs would be chicken feed compared to this idea’s potential, and that this potential is already being realized by potential partners and this is getting him audiences with the worlds hydrogen community, mostly resident in Europe, Australia and Asia.

We will be loading a recording of the interview in the next few days on the Forecasts and Data section of our website and watching the company’s progress with interest.