Why battery-powered aircraft will never have significant range

[BBerson]

The carbon doesn't just build up in the earth.

Right, not today. But large quantities of wood did not decay in the Carboniferous Era, trees didn’t rot and piled up and eventually became coal.

”Based on a genetic analysis of mushroom fungi, it was proposed that large quantities of wood were buried during this period because animals and decomposing bacteria and fungi had not yet evolved enzymes that could effectively digest the resistant phenolic lignin polymers and waxy suberin polymers. They suggest that fungi that could break those substances down effectively only became dominant towards the end of the period, making subsequent coal formation much rarer.[22][23]”

Carboniferous - Wikipedia

en.wikipedia.org

 

[Jay Kempf]

Never say never. Battery tech keeps making very solid gains every year, and battery research keeps making improvements every year. The number of battery tech announcements which occur on a semi-regular basis show we are moving from theoretical to the lab. It only then becomes a matter of moving from the lab to production; which is often measured in one or two decades. Not long at all compared to many other endeavors.

Tim

Battery tech is not making gains when you resolve it to aviation. You can NOT make the lithium be something else. We have made some gains in packaging and safety but those that have pushed the envelope have found the envelope (Boeing 787, Eviation Alice, eFES, Pipistrel, and other early adopters with fires onboard). Making the chemistry resistant to run away and imbalance when charging or discharging is the only opportunity left. That won't make the lithium shed more electrons. It will just reduce the weight of the containment and make the incidence of fires get all the way to an "acceptable risk" for a primary system as far as the FAA is concerned. There is no way you are going to get the propulsion weight fraction of an airliner low enough to make lithium batteries for primary propulsion viable as compared to today's airliners. Sorry. People need to not be bamboozled by this stuff.

We can make a limited mission low PAX count short distance airplane viable right now but it is not a simple engineering problem and charging turn around is the crux. Beyond that the structural fractions get too skimpy to even consider anything viable. Long distance, fast, high payload structural fraction, all out of reach until Mr. Fusion is available.

 

[blane.c]

Mr. Fusion? Lets talk about him?

 

[Jay Kempf]

 

[Dan Thomas]

Never say never. Battery tech keeps making very solid gains every year, and battery research keeps making improvements every year. The number of battery tech announcements which occur on a semi-regular basis show we are moving from theoretical to the lab. It only then becomes a matter of moving from the lab to production; which is often measured in one or two decades. Not long at all compared to many other endeavors.

Tim

The Nickel-Cadmium battery (NiCad) was invented in 1899. 123 years ago. It took over 90 years for it to be developed to the point that it would work for my cordless tools. It was more common in large aircraft, where the starting current requirements were larger than lead-acid could provide without weighing far too much.

The Lithium-ion battery was first developed by NASA in 1965. In 1974 the modern Li-Ion battery was developed. it took "only" 30 years or so to get that one commercially viable.

This stuff takes time. Read the history of the developments and see that an awful lot of experimentation was needed to get these things to work.

Maybe someday we will have enough understanding of chemistry and quantum physics to work out the best battery on paper first, then go ahead and built it and have it perfect first time around. Sure would save a lot of time.

 

[Dan Thomas]

Sure, small share of carbon will get entombed long term to become coal in millions of years. The timescale of that makes it irrelevant to this topic.

When Mt. St. Helens exploded in 1980, it shoved tons of rock and ash down the face of the mountain, shearing off millions of tress and piling them into Spirit Lake and burying them deep. Some years ago I read that some folks went in there with drilling equipment, and when they brought the cores up from down there they found coal. In 20 years. Pressure and heat.

 

[Jay Kempf]

The Nickel-Cadmium battery (NiCad) was invented in 1899. 123 years ago. It took over 90 years for it to be developed to the point that it would work for my cordless tools. It was more common in large aircraft, where the starting current requirements were larger than lead-acid could provide without weighing far too much.

The Lithium-ion battery was first developed by NASA in 1965. In 1974 the modern Li-Ion battery was developed. it took "only" 30 years or so to get that one commercially viable.

This stuff takes time. Read the history of the developments and see that an awful lot of experimentation was needed to get these things to work.

Maybe someday we will have enough understanding of chemistry and quantum physics to work out the best battery on paper first, then go ahead and built it and have it perfect first time around. Sure would save a lot of time.

Just because something developed over a whole lot of years and there were gains doesn't mean that there are MORE gains to be had. The more we dope the chemistry to make it less volatile or safer means they get heavier not lighter. Air batteries and batteries as structure are fallacies. It's marketing of lab experiments to get investor dollars.

NiCAD and Li Poly/ion batteries are already topped out in terms of what can be done with them because the chemistry they exploit is maxed out. Energy density is energy density electrons per atom is a fixed thing. We are already playing with the second most volatile element out there and the 3rd lightest. Where ya gonna go next. Someone going to redefine what a battery is? There are those that are already thinking that they are gonna make hydrogen fuel cells practical. How's that going? We're at the end of the line electrochemically. What is so hard to understand about this? We're playing with volatility that makes a giant tank of flammable liquid look safe and efficient by comparison. Isn't that a problem?

 

[Dan Thomas]

There are those that are already thinking that they are gonna make hydrogen fuel cells practical. How's that going?

I've been reading about hydrogen fuel cells since the early 1980s. Ballard, of Vancouver BC, was formed in 1979 to build them. So far, they have delivered some to drive buses and forklifts and the like, but they haven't caught on in cars, perhaps because of poor range, or perhaps because there are no hydrogen refuelling stations. In any case, they're a long ways from practically powering airplanes.

 

[Aesquire]

I've been reading about hydrogen fuel cells since the early 1980s.

You must be a child!

1960's. I'd have read about them sooner but I was a slow learner and was nearly 4 before reaching fluency in written English. ( tested high school level by 3rd grade, meaning post grad college by today's standards )

Yeah that'd be bragging but I taught my sister to read by 3 in self defense. "Watch your sister" "but I'm reading!" "Then read to her. ". So she got Arthur C Clarke & Heinlein & Tom Swift & yeah, Popular Science.

Hydrogen cars are slowly expanding in places to refuel. The local airport has the only station I know of closer than NYC. But the filling station web site doesn't list it. ( I know because they had an explosion/fire and was repaired. ) It's also right next to the bike path I frequented before the Redacted.

And iirc the Stuttgart flight was with a fuel cell plane. ( the one I made fun of by comparing it to free flight soaring hang glider records ) Quite the accomplishment, really.

Once there's a storage technology that isn't highly pressurized gas, explosive cryogenics, or red hot metal matrices, aka, something that can sit in your wing without far more risk than a gasoline tank, then I'll get enthusiastic.

There are NO ZERO RISK WAYS to have high density energy storage.

 

[ElectricFlyer]

This was posted earlier in the thread; with a less sensational headline.
Does it have the ability to make significant change? Yes, but they are a long way from production and the ability of the average Jane to buy one.

Tim

"with theoretical energy densities several times that of currently available lithium ion batteries"
Why is it still theoretical? They either have or have not proven it -- does it still need to be peered reviewed? Potential to hold up to! Need to improve cycle life!
I think they have a long long why to go and posting a paper is only to get founding. Crossing my fingers and wishing them all the best.
Cheers

 

[tspear]

@ElectricFlyer

It is theory: this is a short but descent summary: Lithium–air battery - Wikipedia
The lab in Japan based on the published paper has demonstrated the first "reusable" Lithium-Air battery that I have read about. There might have been others, but in any case, the Japan lab demonstrated an energy density roughly five times higher than current generation.

@Jay Kempf

In an ICE combustion event, we theoretically have access to every atom. This is a significant reason so much raw theoretical power is actually released (how much is converted to useful energy is a separate debate, we do access very close to the peak of what is theoretical). While in battery tech, you will find that we access very little of the theoretical energy, often due to the thickness of the anode/cathode layers along with the mass taken up by the electrolyte.

If you look at the advances over the past decade from Panasonic, LG, GM, Ford.... the advances are significantly more on the production side by reducing the amount of raw materials used to produce the same power. We still have a long way to go on this front in terms of producing reliable and well known/understood battery management systems.

At this point, battery tech is closer to the early 1900s for the ICE engine when fires and other issues were "common". In fact ICE had a significantly rougher start than batteries have, it is just that most of us have forgotten the history and have built a reservoir of knowledge to prevent these issues for ICE. This journey for battery tech is effectively just starting.

Tim

 

[Jay Kempf]

Lithium only has 3 electrons per atom. What is going to change that? Lithium has a fixed density. What's going to change that. The more stuff you add to it the heavier it gets. What's going to change that?

You can say well I put the same amount of lithium in a larger housing that was lighter (like a lithium air battery) and I get less density per volume than some other battery. But the lithium didn't change.

The journey you say may be staring but the chemistry is at the end of the available options.

How many times in that article did it say "excluding the oxygen mass?" And how many times did they have to disclaim that you have to add back electrolyte and mention cooling and housings and structures.

You can keep hoping but you have to add stuff to lithium to make it stable and extract any current. All those things decrease the power density they don't increase it. Everyone that has pushed lithium too hard has found the end of the line. In a car you can put these batteries outside the cockpit and you can just stop and get out and run away from the fire. For an airplane you have to create a survivable emergency procedure. The harder you push whatever battery chemistry involving lithium for more current out of less pounds the worse the problem. Wish it wasn't true but it is. Sorry.

 

[8davebarker]

Alternate safe way to store hydrogen as NH3 ammonia. Simple small catalysis device converts 2NH3 to 3 H2 and and N2 on demand.
see: Kontak Hyrdogen Liquid Storage |

 

[Dan Thomas]

Lithium only has 3 electrons per atom. What is going to change that?

Not being much good at chemistry, I have to ask how many of those three electrons are available for exchange?

Alternate safe way to store hydrogen as NH3 ammonia. Simple small catalysis device converts 2NH3 to 3 H2 and and N2 on demand.
see: Kontak Hyrdogen Liquid Storage |

From Wiki:

Although common in nature – both terrestrially and in the outer planets of the Solar System – and in wide use, ammonia is both caustic and hazardous in its concentrated form. In the United States it is classified as an extremely hazardous substance, and is subject to strict reporting requirements by facilities which produce, store, or use it in significant quantities.[13]

NH3 boils at −33.34 °C (−28.012 °F) at a pressure of one atmosphere, so the liquid must be stored under pressure or at low temperature. Household ammonia or ammonium hydroxide is a solution of NH3 in water. The concentration of such solutions is measured in units of the Baumé scale (density), with 26 degrees Baumé (about 30% (by weight) ammonia at 15.5 °C or 59.9 °F) being the typical high-concentration commercial product.[17]


Sounds real safe, doesn't it?

 

[Dennis K]

As part of the weather detachment supporting the Black Bird program out of Okinawa I maintained the upper air tracking equipment that included a hydrogen generator we were supposed to use to inflate the weather instrument carrying balloons to high altitude. It consisted of a heating blanket wrapped around an ammonia cylinder that piped gas past a platinum catalyst to generate hydrogen. It came equipped with a 100 foot starter cord as a safety precaution and for good reason as it blew up with alarming frequency. Notwithstanding the entertainment value we seldom used it as the hydrogen it produced proved to be too wet. The moisture condensed onto the insides of the expanding balloon, freezing there before cracking and either bursting it by falling to the bottom or puncturing it on sharp ice crystals before the balloon and its instrument package reached the required altitudes. In the end we switched to bottled gas as it was much dryer. Hydrogen cylinders are big and heavy and that also caused some interesting occurrences. I would usually detail six or so airmen to accompany me to the storage area to load a deuce and a half full of cylinders and then unload them at the "R - Section" (Rawin site). As any welders know the cylinders are too heavy to pick up so you grasped the protective cap screwed over the valve assembly at the top and tipping the cylinder, rolled it to and fro in the general direction you desired. Evidentially, there is a deep seated fear embedded within the generation schooled in videos of the Hindenburg disaster because when one of the caps was loose and turned slightly letting out a loud squeak the entire crew evaporated into thin air and left me holding the cylinder all alone in the bed of that truck. It was the fastest I had ever seen any of them move except at happy hour.

 

[Vigilant1]

In the end we switched to bottled gas as it was much dryer.

I'm surprised helium wasn't preferred. Its got just 8% less lift, but a lot less drama. Maybe it's hard to get in some places. It's certainly a LOT harder to make.

 

[Vigilant1]

An aside: In another thread recently we were talking about now extinct analogue technologies. Your ref to USAF weather detachments reminded me of another one: the "magic writer." The guy in the base weather shop would write out his observation or prediction using the groovy weather hyroglyphics on a special little machine with a pen/stylus. At other locations (Base Ops, the squadrons, maybe the tower), a little servo-driven pantograph would replicate the writing on a piece of strip paper. The last 2 feet of paper were visible so you could see about the last 5 observations. Sure, clunky and expensive compared to just keyboarded text to a bunch of terminals, but infinitely cooler. If he drew Sparky the Clown, then that's what all the slaved units drew.

 

[Aesquire]

In the American Civil War observation balloons were in some cases inflated by a Hydrogen generator wagon. A wood tank lined with sheet metal, with sulfuric acid, & Zinc scrap ( often removed from homes along the path of the balloon unit & surrounding the operating area ) tossed in to generate lifting gas.

All very low pressure and basic gear.

In many cases "town gas" was used where available. I presume with varying levels of LTA lift.

There are more dangerous materials to carry than Hydrogen. Acetylene, antimatter, lab monkeys, and FOOF. Just as examples.

The simple science...

https://www.realclearscience.com/blog/2015/06/foof_the_chemical_most_chemists_avoid.html

"things I won't work with" a wonderful collection of terror and humor. Well worth the read.

Science | AAAS

www.science.org

 

[Aesquire]

Just had to post the best title ever to a Chemistry article!

Science | AAAS

www.science.org

As I've said before, Hydrogen is, outside a Bussard Ramscoop, a storage media for Lots of energy, and not very efficient overall. The nice Ammonia/Catalyst/Magik website above says they can make the hydrogen from cheap feedstocks. That's going to probably be natural gas. Although Beyond Thunderdome pig manure methane is good too. In any case you take either a more common and easier to use fuel and make it harder to store and ship, or you blow VAST amounts of power into splitting it from water.

I'll recommend this sci-fi action thriller for a fictional version. It's not a bad film.

Chain Reaction (1996) - IMDb

Chain Reaction: Directed by Andrew Davis. With Keanu Reeves, Morgan Freeman, Rachel Weisz, Fred Ward. Two researchers in a green alternative energy project are put on the run when they are framed for murder and treason.

m.imdb.com

Yes, you can buy a Hydrogen powered Toyota. Yes, there are limited areas to fill one. Yes, it's exciting technology. And yes, I'd rather carry a composite hydrogen pressure tank than the T-stoff & C-stoff used in the Me-163.

Which isn't an endorsement. I don't want Me-163 rocket fuel anywhere near me. I'd rather deliver bee hives. ( which I have done )

 

[Dan Thomas]

I'm surprised helium wasn't preferred. Its got just 8% less lift, but a lot less drama. Maybe it's hard to get in some places. It's certainly a LOT harder to make.

There are helium wells being drilled around here in Saskatchewan. It's a product of the decay of uranium and thorium, as I understand it. Probably a lot cheaper than distilling it from the air.