Hydrogen fuel cells: With a database of 500,000 materials, researchers zero in on best bets

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As researchers work toward next-generation electric vehicles, they may be hitting their heads on the ceiling of what lithium ion batteries can deliver.

Meanwhile, a team of researchers from the University of Michigan are pushing the performance of a competing electric vehicle technology— —to new heights.

A hydrogen fuel cell is a zero-harmful-emissions power source that acts like a cross between a battery and a gas tank. It employs hydrogen as the fuel and harnesses the reaction between hydrogen and oxygen to produce electricity. The only "emission" is water.

One limitation of this technology is the ability to store sufficient quantities of hydrogen onboard. The U-M researchers have identified ways to cram more hydrogen than ever before into small storage structures called , increasing the , and, as a result, the projected driving range of a fuel cell vehicle.

Metal organic frameworks, or MOFs, are comprised of metal ions coupled with organic molecules. Their porous nature makes some MOFs among the most promising ways to store hydrogen.

Michigan researchers gathered information on all available MOFs, those previously constructed as well as those that remain hypothetical, into a database. High-throughput computer simulations were then used to scour the resulting databank of nearly 500,000 MOFs for those having promising capacities.

Three candidates were identified that could surpass previous records for hydrogen storage. The researchers then synthesized these materials and demonstrated their performance.

"We're demonstrating more energy-dense storage than previously shown," said Don Siegel, U-M associate professor of mechanical engineering. "You might describe it as more efficient—putting more energy into a smaller space and in a lighter package."

As published this week in Nature Communications, the three MOFs are dubbed SNU-70, UMCM-9 and PCN-610/NU-100. Each surpassed the performance of IRMOF-20, another MOF identified by the team in 2017.

"These materials establish a new high-water mark for usable hydrogen capacities in MOFs," the study states.

Hydrogen fuel cells have long held promise as a no-emission power source for . They have, however, taken a backseat to lithium ion batteries, which you'll find inside most of the portable electronic devices being produced today—from cell phones and tablets, to digital cameras and electric vehicles.

Hydrogen fuel cell systems have several advantages over lithium ion batteries. The most in the universe, hydrogen is far more common than lithium, so there is little chance of there ever being a supply issue.

And a hydrogen fuel cell car can recharge at a station in a few minutes, about the same time it takes to fill a gas tank now. In contrast, full charge times for lithium battery electric vehicles are typically measured in hours.

There are drawbacks that have limited the auto industry's embrace of hydrogen, however. For example, producing hydrogen is currently much more expensive than is extracting and refining petroleum.

Transportation of hydrogen fuel is another issue. As a gas, it's difficult to move and store large quantities of hydrogen efficiently, raising questions of whether it needs to be moved in liquid form in semitrucks or shuttled through pipelines as a gas.

But the lure of what hydrogen could potentially mean for cars, and the environment, has kept major automakers like Ford, Hyundai, Toyota, Honda and GM involved in its development.

Electric designers are constantly looking to decrease the size of a car's power system as a means of increasing efficiency. By increasing the quantity of hydrogen that can be stored in a MOF adsorbent, Siegel said, the pressure needed to store it can be reduced. The size of the tank can also be reduced.

"We want to eliminate the energy storage problem for vehicles. This shows we're moving in that direction," Siegel said.


Explore further

Paving the way for more efficient hydrogen cars

More information: Alauddin Ahmed et al. Exceptional hydrogen storage achieved by screening nearly half a million metal-organic frameworks, Nature Communications (2019). DOI: 10.1038/s41467-019-09365-w
Journal information: Nature Communications

Citation: Hydrogen fuel cells: With a database of 500,000 materials, researchers zero in on best bets (2019, April 5) retrieved 22 April 2019 from https://phys.org/news/2019-04-hydrogen-fuel-cells-database-materials.html
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Apr 05, 2019
A bottle of propane holds more hydrogen than any MOF, at a fraction of the cost. The researchers are just dancing around the obvious solution of using hydrocarbons to store the hydrogen because CO2 emissions are effectively being outlawed regardless of source, so making fuel cell cars that burn regular fuels are made politically impossible.


Apr 05, 2019
Considering that you have to generate 3 times more power (i.e. build 3 times the powerplants) for the same amount of mobility using hydrogen as opposed to batteries it's easy to see how this tech is dead-on-arrival for cars. This isn't just a question of better tech. It's just plain physics. You can't cheat physics.

As for 'hitting the ceiling': What exactly do you need in a car? 1000 miles range? No. (But even such a ludicrous demand would still be achievable with batteries.)

Then there's the hugely costly infrastructure for hydrogen refueling. One to two orders(!) of magnitude more costly than for battery vehicles. All of that extra investment is going to have to be paid for. At the pump. You betcha.

But I get it: companies/governments love hydrogen. Nothing screams "profit" like something you HAVE to buy from a third party and which you can easily tax.

Apr 05, 2019
Back in the 1990s I thought fuel cell EVs had a decent chance against battery EVs (BEVs) because the batteries we had at the time were not very good. Time has proven that guess wrong. BEVs have won the war. Game over. The fact that you can use the already existing global electrical grid to charge your BEV, or your own home solar array, is a gigantic advantage fuel cells will not be able to overcome.

Behind the scenes, the Tesla Model 3 is a shockingly, stunningly good vehicle at its current price range. As the public slowly comes to understand this, the powerful automotive and oil industries will be completely transformed. Now that BEVs are set to take over, the automobile and oil industries may develop a new found love for fuel cell EVs, but it is far too little, far too late.

Maybe in the distant future an even better power source will be developed, but here in 2019, the best answer for both the individual and the planet as a whole is BEVs.

Apr 05, 2019
Back in the 1990s I thought fuel cell EVs had a decent chance against battery EVs (BEVs) because the batteries we had at the time were not very good. Time has proven that guess wrong. BEVs have won the war. Game over.

I was of the exact same opinion back in the 90's.

I still think there are applications for hydrogen where other factors are paramount besides efficiency: particularly when it comes to long term storability, weight and energy density.
So the uses I still see are:
1) Storing energy from excess PV generation in summer for winter use
2) Electrifying the (long range) airline sector. (short range seems already to be a foregone conclusion in favor of batteries)
3) International shipping - because cost scales with surface area for hydrogen fuel tanks while it scales with volume for batteries. (On national transport levels it already looks like batteries will win out here, too)

Apr 05, 2019
Considering that you have to generate 3 times more power (i.e. build 3 times the powerplants) for the same amount of mobility using hydrogen as opposed to batteries it's easy to see how this tech is dead-on-arrival for cars.


You lose the same and more by constructing and buying batteries for the purely electric vehicle (money is energy: work required to run the economy for the corresponding amount).

Even if you lose 2/3 of the energy, the use-value of a hydrocarbon fuel made of electricity turned into hydrogen is greater than the use-value of unusable random wind/solar power or whatever similar thing you have. That's why people pay so much for gasoline, even when the resulting energy output is 3-5x more expensive than electricity bought off the grid.

Apr 05, 2019
I still think there are applications for hydrogen where other factors are paramount besides efficiency: particularly when it comes to long term storability, weight and energy density.


Exactly: motor fuels.

What exactly do you need in a car? 1000 miles range? No


Yes. You don't have to use the 1000 miles in one go. Having more in the tank than you need means you don't have to worry about supply shortages, and you can choose when you refuel, where you refuel, you can make use of discounts or special offers, take a road trip to the middle of nowhere and still get back...

A standard car can go 400-500 miles on a full tank. Electric cars should do the same -- but only the most expensive models can actually achieve it.

Apr 05, 2019
@Eikka.
A standard car can go 400-500 miles on a full tank. Electric cars should do the same -- but only the most expensive models can actually achieve it.
Again you unnecessarily and self-selectively delimit Battery Electric Vehicle possibilities/advantages, mate. :)

For starters many cars are mainly for work/shopping and other social/family commutes within the same town/city or nearby towns/cities. For the occasional long trips or for the businessman traveling often for long distances there is public/private transportation options (trains/buses/planes). And even for those 'going bush' to remote places there will be the option of ADDITIONAL battery pack (analogous to extra gas fuel capacity in larger tank-size or jerry-cans in trunk/on roof racks).

Moreover, there is one advantage that BEVs have over fossil fuel Vehicles: a simple/cheap mobile/deployable SOLAR PANEL or Wind Turbine can recharge your batteries IN THE REMOTEST places given modicum of sunlight. :)

Apr 05, 2019
I have an EV. It is one of those 'expensive' ones.
Funny thing is: if you factor in all the savings then it's actually cheaper overall than a comparable gasoline car (Not only in terms of 'fuel' and maintenance but also when it comes to resale value it far outperforms equivalent ICE cars...aside from outright outperforming ICE cars in any and every other category like perfomance, safety, how much time I have to spend on caring for and fueling it and -of course- eco-friendliness).

Apr 05, 2019
AAP, I believe you may have the same EV that I do, i.e., a Tesla Model 3 AWD. After nearly 6 months and 4,000 miles, I love mine even more. It sounds like you are enjoying yours too.

I am sure there were people like Eikka arguing that the automobile would never be able to replace the horse. LOL! Times change Eikka, just accept it. I for one am incredibly glad we can make the case for EVs based on practicality alone. However, I will state for the record that I am deeply concerned about global warming. I am not an alarmist, but if we can't get CO2 levels to start falling in this century, billions will suffer and worse. If we stumble into an unexpected feedback situation, e.g., massive methane outgassing in the Arctic as the permafrost melts, it is unclear what it will take to undo all the environmental damage. This is on us.

Apr 05, 2019
Every electric car in China emits far more effluents than do gasoline cars in America because electricity in China is primarily generated by coal. Hydrogen is and always will be much more expensive and the world is awash in new oil discoveries.

Apr 06, 2019
AAP, I believe you may have the same EV that I do, i.e., a Tesla Model 3 AWD. After nearly 6 months and 4,000 miles, I love mine even more.

Yeah, got mine 3 weeks ago. Pretty amazing piece of tech. Already put it throug the paces. Everyday driving. Longer trip. Works just fine and the time for the trip was the same I had with my previous (ICE) car.

Oh, and I did go to a gas station...to check the tire pressure.

Every electric car in China emits far more effluents than do gasoline cars in America because electricity in China is primarily generated by coal.

Even an EV run on 100% power from coal powerplants produces less CO2 (and far less NOx) than an ICE. Coal powerplants are far, far more efficient than a gas engine 8and can have far more efficient filters for particulates)
The energy mix in the US and China regarding the distribution of non-renewables and renewables is pretty much the same.

Apr 06, 2019
@Mark Thomas
@antialias_physorg
@gkam.

@MT and @antialias. Do either/both of you have solar panels to charge your EVs at home like @gkam has?

@gkam. How far can your home-charged EV go now that you've had it a while; I mean, has the recharge/discharge efficiency/capacity degraded in any significant way?

Cheers all. :)

Apr 07, 2019
@MT and @antialias. Do either/both of you have solar panels to charge your EVs at home like @gkam has?


Not yet, but I have been planning to get a PV system added for some time now. I understand the technology has matured to the point where this makes financial sense for a great many people and I particularly like the Tesla PV roof tiles. A friend who got them said because he needed a new roof anyway, the financial case for obtaining the Tesla PV roof tiles was compelling.

Apr 07, 2019
Not yet, but I have been planning to get a PV system added for some time now.

Since I live in a loft complex that's (unfortunately) not an option for me. Should the house community want PV I'd happily chip in my share (and then some).

I understand the technology has matured to the point where this makes financial sense

You can recoup the money in roughly 10 years (depending on where you live this may vary up or down a bit depending on electricity prices and insolation). Given that panels last basically forever without any maintenance (maybe a new inverter every decade or so) that's a steal.
If you can buffer some of what you produce during the day and charge your car with it at night that's even better.

Apr 07, 2019
@Mark Thomas
@antialias_physorg.

@Mark Thomas. Thanks for response. Good luck with solar panels in your future. FYI: Here in OZ, we are among leading 'uptakers' of rooftop solar...and NOW the Labor Party (which has always supported climate science and action) is promising to encourage even further uptake by subsidising domestic battery storage costs so all can get the best out of their solar panels (including for their car-charging at night!). They also have policy for target of 50% electric vehicles on road as soon as they can manage it via policy/incentives etc. The coal/oil backers in the Conservative party (calling themselves Liberal-National Coalition) are having conniptions!...because the moderates in their own coalition are now stopping their AGW-denial, and starting to make policy towards renewables future ( but it may be a case of too little, too late for them at our next election in May sometime)!

@antialias_physorg. Move a motion at your next house meeting! :)

Apr 08, 2019
AAP and RealtyCheck, thank you for your messages too. It was good to read that the moderates in Oz are now stopping their AGW-denial. From my perspective as a one-time tourist in Oz that loved the place, climate change has been hitting Australia particularly hard. Between the high temperature records, fires, extreme weather events and massive damage to the Great Barrier Reef, Deniers must be struggling to spread their lies.

https://en.wikipe...ustralia

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