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There's a check-list floating around here on HN with all the possible reasons why we won't be seeing this in production any time soon, but I can't seem to find it. Hope some fellow HN'er posts it so we can stop being all excited.
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Dear battery technology claimant,

Thank you for your submission of proposed new revolutionary battery technology. Your new technology claims to be superior to existing lithium-ion technology and is just around the corner from taking over the world. Unfortunately your technology will likely fail, because:

[ ] it is impractical to manufacture at scale.

[ ] it will be too expensive for users.

[ ] it suffers from too few recharge cycles.

[ ] it is incapable of delivering current at sufficient levels.

[ ] it lacks thermal stability at low or high temperatures.

[ ] it lacks the energy density to make it sufficiently portable.

[ ] it has too short of a lifetime.

[ ] its charge rate is too slow.

[ ] its materials are too toxic.

[ ] it is too likely to catch fire or explode.

[ ] it is too minimal of a step forward for anybody to care.

[ ] this was already done 20 years ago and didn't work then.

[ ] by this time it ships li-ion advances will match it.

[ ] your claims are lies.

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I would love to see a timely spreadsheet with each breakthrough and how it went.
>Your new technology claims to be superior to existing lithium-ion

To be fair, it doesn't. The article is explicit that it's only 20% as mass efficient s lithium-ion battery.

On the other hand, it's also true that the vehicle aluminium mass is mostly dead weight, so exploiting it to serve as a battery doesn't seem insane.

Except now, they need to know what to do when something hits it, breaks it, etc... So I'm not convinced this is a good idea for cars (or for anything), but at least, it goes in a direction that actually seems new instead of just doing "same but better". I could actually see that used as a support for solar panels so that they would litterally ship "batteries included".

Or even as a supplement to a conventional battery - being able to squeeze in 10% more energy capacity without expanding the battery could be a way to incrementally improve range. And also possibly provide a small backup power source in case of main battery failure.
> To be fair, it doesn't

Well yeah, there's no check in the checklist, nobody claimed that.

* this was already done 20 years ago and didn't work then.*

This is a standard wet-blanket unhelpful remark that doesn't belong in the list.

Maybe it should say "didn't explain why it will work now when it failed in the past"?
good points! having worked a bit in a close field i'd add:

[ ] is impossible to recycle

I've seen this checklist before and it is infuriatingly lazy, like taking the famous HN lowbrow dismissal and turning it into a meme, but actually taking the meme seriously.

Lithium-Ion batteries are not the most superior battery. They might be the best we have for some use cases, but obviously not all, or they would have 100% market share. They haven't replaced disposable alkaline batteries. They haven't replaced AGP batteries. They haven't replaced Lead Acid batteries. They haven't replaced Lithium Iron Phosphate batteries. There are plenty of reasons why: cost, weight, safety, shelf life, etc.

Since Lithium Ion doesn't have 100% market share, a useful comparison does not have to be with Lithium Ion in order for a battery technology to be a meaningful advance. And even if it did, sometimes an advance in just one area can be enough to overcome its disadvantages in other areas.

Example: I use Lithium Iron Phosphate in my sailboat. Yes, it has lower energy density. Yes, it has lower power density. Yes, it is more expensive. Yes, it has shorter lifecycle. Yes, it has a slow charge rate. It has one solitary advantage over lithium ion, and that single advantage is the difference between life and death: it is more chemically stable and thermally stable, and less likely to result in fires.

If you have a fire in your car, that sucks...but you can just open up your car door and walk 20 feet to safety. You hop on your cell phone and call AAA or a taxi or a friend. If you're on a sailboat in the middle of the ocean, you can't do that. Even if you've planned well, with a ditch kit, a liferaft, and an EPIRB, you are still potentially several hours or even days before someone can get to you to get you to safety. In the meantime, you're floating on an ocean with waves taller than your liferaft, with a limited supply of food and water, and you have a tiny plastic membrane separating you from a place where you would need constant energy to survive and where you are no longer the top of the food chain.

So with all due respect, fuck lithium ion. And fuck this list. There is plenty of room for advances in battery technology, and we don't need religious charlatans from the Cult of Musk shitting on every single battery tech announcement.

The point isn't that Lithium Ion batteries are that great, but that most of the press articles are hyping something which at best is a few years in the future. There is a huge gap between even the best science and a technology which is ready for production and can be rolled out into large-scale manufacturing. Even if there are for-real samples around for people to play with, it could take years until they make it into a car. And then of course, there is some risk that the initial science isn't even good. That happens too.
"Researchers from Chalmers University of Technology have produced a structural battery that performs ten times better than all previous versions"

It's 10 times more everything, just like every other battery breakthrough in the last several decades. AND, you get to use it as a building material?

- Sounds too good to be true: Check

- Sounds like every other "big" breakthrough: Check

- Article light on science and heavy on assertions: Check

- Skepticism engaged: Check

Presumably that should be read: Better than previous “massless battery’s”.

    “... produced a structural battery that performs ten times better than all previous versions”
I recommend people read the article, it actually has some information. More info:

"The battery has an energy density of 24 Wh/kg, meaning approximately 20 percent capacity compared to comparable lithium-ion batteries currently available. But since the weight of the vehicles can be greatly reduced, less energy will be required to drive an electric car, for example"

"the researchers did not choose the materials to try and break records – rather, they wanted to investigate and understand the effects of material architecture and separator thickness." - this implies there may be a lot of room for improvement with this design.

then the question becomes how are they solving for the increased heat.
In increased surface area-to-mass ratio would probably make this easier.
Which makes it heavier no?
No. A rectangular block of a typical battery has a much lower surface area-to-mass ratio than a tube, even if their weights are the same. It's why cooling fins on a CPU are long and skinny. Such length and skinniness makes heat dissipation much easier.
But if the energy density is higher wouldn't you need more material to cool down the area?
Add a qualifier and you can claim almost anything!

The Fastest Sports car! [1]

[1] with a 3.2-liter horizontally opposed flat 6-cylinder engine

Indeed. From the perspective of battery chemistry technology this paper is utterly unremarkable.

But then that's not what it is about. The breakthrough is (oversimplifying here) that they invented a way to whack a bog-standard smartphone battery into the middle of a bunch of layers of building material, such that about 20% of the weight of the end product is battery, whilst the material is still strong enough to not cause a Samsung Galaxy Note style oopsie when structurally compromised, and to be strong enough to build with, and to have some of the mass of the battery improve the structural integrity of the whole, even.

The idea being: Take your tesla. Take the batteries out. Smash em to paste. Remove ~20% of the atoms from the chassis materials and replace them with your paste.

Voila - made your car 20% lighter.

btw, tesla is already doing that in production now. They have a new structural battery, although no carbon fiber yet.

I think there might be lots more low hanging fruit, their cars weigh quite a bit.

For me has gotten down to this: "New" and "Battery" in title => Don't read, not worth enthusiasm.
Yet we have had massive increases in battery performance over the last couple decades.
It's surprising how all breakthroughs are precisely, always, 10 times better. Let's wait until a HN battery expert tell us
Maybe nobody does research on tech that isn't at least 10 times better than the stuff we already have?
A 2x increase for battery storage would be game changing for a wide variety of use cases. Electric vehicles, industrial applications...
Battery tech is improving at around 10% a year. Lithium Battery density has tippled in the last 10 years people on hacker news like to comment on how new battery technology has not done anything but since those comments started a decade ago battery density has trippled.

https://cleantechnica.com/2020/02/19/bloombergnef-lithium-io...

If it's improving at a rate of 10% per year, a 2x would take 4-5 years to achieve so a 2X is really a good improvement. I wonder where we'd be right now had we not gone the ICE route.
Reality is most new technologies need to be 10 times better to get investment. Otherwise it is generally assumed that by the time new technology gets into production the older tech will still have cost advantage. This is the main reason why we need government investments for unprofitable research.
Or when it's only 5x better, they quietly continue tinkering around, and only when it's 10x better do they announce their results and try to get funding.
"Its multifunctional performance is ten times higher than previous structural battery prototypes."

The problem is we don't really know what multifunctional performance means or how it's defined, but maybe this is a common metric in battery technology?

edit: I skimmed the actual paper linked in the article and it doesn't mention a 10x improvement.

"Structural battery composite materials, exploiting multifunctional constituents, have been realized and demonstrate an energy density of 24 Wh kg−1 and an elastic modulus of 25 GPa. Their combined electrochemical and mechanical properties outperform all previous structural battery materials reported in the literature. "

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In this house we obey the laws of thermodynamics.
I know what my next (self) carved den plaque is going to say now.
I wonder if the switch from Nickel Cadmium to Lithium Ion batteries was also hyped the same way (my google fu is failing me).

But even there, I feel like you can't just sum things up and say "LiIon are 10x better than Nickel Cadmium" there's a whole range of requirements.

I couldn't find anything about net inprovement over "massfull" batteries.
In reality, it's 5x worse than current LiIon tech(from the same article):

> The battery has an energy density of 24 Wh/kg, meaning approximately 20 percent capacity compared to comparable lithium-ion batteries currently available. But since the weight of the vehicles can be greatly reduced, less energy will be required to drive an electric car, for example, and lower energy density also results in increased safety. And with a stiffness of 25 GPa, the structural battery can really compete with many other commonly used construction materials.

This seems a bit more believable. Whether it'll actually be used in that manner is to be seen, but this seems more down to earth. And while the article seems to put emphasis on using it to save weight, it's probably more effective to use it to add capacity while maintaining weight.

For a Tesla Model 3, the vehicle is about 1600Kg with battery, and the battery is about 500Kg. The battery is heavy, but less than a third of the vehicle weight.

Aircraft, though... Aircraft already have "wet wings", which are fuel tanks. If the battery provided some of the wing's structural strength, that might work. Probably worth trying in military drones first.

It may really be 10x, but you've mischaracterized what the paper is claiming a 10x breakthrough for. In fairness, the linked article is light on the specifics.

The claim is:

__This battery holds 10x more charge per kilo of material than previous attempts at STRUCTURAL (massless) battery materials__.

To be specific, this material holds only _ONE FIFTH_ the charge of what your smartphone's battery can hold per kilo of battery. No laws of thermodynamics is being broken and this is not at all about battery chemistry. It's all about the 'physics' of construction materials: About how this stuff is made in the factory and layered. The basic battery chemistry going on is not much different from what's been available for years - the interesting part is how this material encases it.

You can't make a car by building the chassis out of smartphone batteries. But the promise of this paper is that you CAN build the car chassis out of this battery, and even if this battery is only 20% as effective, a car chassis is rather large, and you needed it anyway, so every drop of power you can store in the chassis itself was effectively 'free' - hence the somewhat hyperbolous 'massless' terminology.

Hopefully it'll be easy to repair. I'd hate to replace entire chassis because of light collision.
If your fender bender short-circuited your battery and ignited it, you might need a wee bit more than just a new chassis.

(This is not a claim that the batteries described in the article are a fire hazard - I don't know)

A mechanic working on a car, with enough juice to fry him, and no way to separate the battery from car?

I guess a full discharge first.

But what about your accident, and the jaws of life? Will they conduct? Will the wrenched apart car have conductive edges?

Interestingly, these are actual concerns that firefighters have regarding both Teslas and self-driving cars. The relevant companies put out explainers and training videos on how to do a rescue in these vehicles.

In the Teslas, the power system is shunted through a single disconnect point... Cutting that line isolates the battery from the rest of the vehicle.

In Waymo cars, firefighters needed to be made aware that high-power electrical conduit and liquid cooling channels go up through the pillars, which are usually empty of energized components or contain only low-power channels (for things like overhead lights).

That's interesting. I never considered this to be a problem but it makes sense. This could be quite challenging if every car manufacturer does something different, but I suspect over time just like with ICE cars they'll iterate towards some local optimum and things start to be very similar.
>I suspect over time just like with ICE cars they'll iterate towards some local optimum and things start to be very similar.

This doesn't happen organically. Manufacturers were happily iterating toward a different optimum before regulation forced their hands.

https://www.nytimes.com/2015/11/27/automobiles/50-years-ago-...

That's not really what I mean though. I'm well aware that without regulations short term incentives and optimization can lead to bad outcomes. What I mean is something along the lines convergent evolution where certain designs keep re-appearing because they just work better than the rest.
That's pretty much the status quo for EVs now; the batteries are hundreds of volts and you can't easily remove it. Draining it isn't an option either, as it damages the battery to be fully discharged. So, you have to work on the car with a live voltage source present.

I'm not sure if most modern EVs have manual disconnect switches on the main power cables where they meet the batteries or if you're just expected to wear rubber gloves and use non-conducting wrenches to unbolt the cables. I'd expect any modern EV will at least have contactors to connect the battery to the motor controller (these are basically electrically actuated switches, like a mechanical relay), which will be disabled when the car is off. In general, though, I'd expect the main power cables to be something that doesn't need maintenance and mechanics can generally steer clear of.

In the article, they say they're using a lithium iron phosphate chemistry. Those tend to be pretty safe. Or at least as safe as you can reasonably expect anything to be that can dump hundreds of amps across a closed circuit.
My thoughts exactly. Load bearing structures tend to be permanent or not frequently changed (on the order of decades). Now someone wants to place a battery in that structure?

I hope they develop a mechanism that allows exchange of the battery and can bear load without the battery with some sort of mechanical movement that can shift the load to a more permanent structure (not that this is necessarily a good idea either but proposing an option). Or, perhaps the battery never needs changed, and by that I mean the life of the product lasts as long as it would with a replaceable battery. They can't just redefine the life of the product as the life of the battery to get around this (unless the life if the product was already defined by the life of the battery for a long time before).

How about the structural problems with composites that occur with use ... Fractures from normal wear and tear (over years) in a composites will lead to catastrophic failure of the part
Repairability is guaranteed to be impossible if you have that level of integration, and I suspect that is a big part of the motivation behind adopting this.
Indeed. And having worked with a wide variety of batteries.... I would hate to see a 'load bearing battery under torsional stress'. Just ow.
If you damage carbon fiber you generally won’t be repairing it. This doesn’t sound like it will be a very big limitation for similar use cases.
carbon fiber repair is definitely a thing. i’ve had a few carbon bike frames break and had them repaired without any issues. there’s a few places that specialize in this
Many ultramodern carbon fiber processes don't use an autoclave so one might be able to do production grade repairs in-place.
I would like a very simple electric car, simple motor(s), simple electronics to repair, no GPS or phone home necessary (I want to download on my time, send me a text/email/whatever about critical downloads). I want something easy and cheap to repair, have the simplicity of electric motors, and run 20 years with very little maintenance. I don't 30 computers running on my computer. I just want to get from A to B and it not cost me 80-100k for a decent electric vehicle. Tesla and others are overengineered for what they do and that complexity adds to failure rate and cost of ownership.
Aren't you describing a Nissan Leaf? I can't really speak to the repairability, because even though I've had it 2 years, I haven't had to do anything but charge it. Oh, once I had to put more air in the tires. Great little car, with about a 70 mile range on my 2017 model.
You're not going to get around the 5-10 computers required for basic 21st century automotive safety. But, the rest of what you are describing is the status-quo for quite a few Chinese 'budget' brands.

I'm betting once EVs start making their way into fleets, you'll find your 300k mile, low maintenance, minimal electronics American/German brand.

One way to get what you're asking for is to do a conversion (or pay someone else to do it, or buy one that someone is selling).

I'm in the middle of converting a Mazda RX-8. Just got the motor/clutch/transmission assembly (mostly) in place last weekend. It's kind of fun, but it's also a lot of work. It seems like a tremendously inefficient way to get the car I want: electric, no phone-home or over-the-air update capability, ability to control how everything works, easy to fix, manual transmission, modern safety features. I thought about buying a Model 3, but decided it was a lot of money for something that wasn't quite what I want. 200+ mile range would have been nice though; it's hard to get that in a conversion without making it unreasonably heavy.

Why do you want an electric car with a transmission? It doesn't have an engine in the first place.
Partly because shifting gears is fun. Partly because you can get more usable power out of the motor with a transmission.

It's a bit of a trade-off. To use Tesla as an example, they take the approach of just putting a massively overpowered motor in each car so that they can overcome the lack of a low gear. That works fine, but the kind of parts you need in that sort of system are expensive. Not just the motor, but the motor controller and the batteries have to handle that much power.

A different approach is to just have a normally-sized motor and an ability to shift gears. It should make for a lighter, more efficient car. (Though you also lose some efficiency in the gearbox.) The conversion I'm doing has a 120 horsepower motor, and it's going into a car that's about 3,000 pounds. I won't win any 0-60 races with a Model S, but it'll probably handle corners better and generally be more fun to drive, not to mention be about 1500 to 2000 pounds lighter.

I'm willing to concede that wanting an EV with a stickshift may be an unpopular opinion, but it's hard to know if there's a market for that kind of thing until someone starts manufacturing it. (And I don't mean the Taycan, I mean something that some ordinary middle-class person might buy.) It seems kind of a shame that we have all these legacy car companies that know how to build transmissions, but none of them seem interested in using that as an advantage they have over Tesla for that part of the market that want an electric car but would rather drive a manual transmission.

I suppose back in the day there were those who missed the buggy whip.
>it'll probably handle corners better and generally be more fun to drive

Sounds like a very educational project.

I wouldn't be so quick to just brush off Tesla engineering as having bad tradeoffs, or make assumptions about the fun of cornering, but I'm sure the project will be an eye opener and maybe will lead you to test drive an M3P sometime.

Definitely it's hard to beat an RX8 with cornering but that's before you load it down with batteries.

Edit: I had some doubts about your weight claims but I wasn't thinking about the fact that you are losing the engine weight, which puts you pretty far ahead! Sounds like a cool project.

I don't think Tesla's engineering tradeoffs are bad, I just think that they result in a car that's different than my notion of an ideal car. It's a preference thing more than anything else.

I did actually consider buying a Model 3, and even put down a thousand dollars to preorder back when it was announced. I test drove a dual-motor version (I would have gotten the single-motor version, but it's what they had). The acceleration is fun. Otherwise it seemed like a solidly built yet kind of generic car. In the end, the main things that kept me from buying it were Tesla's secretive nature when it comes to service information and the prospect of some minor component failing and bricking the car (like that flash chip soldered to a giant motherboard that had issues in early models) after the warranty expires, and the price being a bit more than I cared to spend on a car. Awhile later a friend showed off a Ford Ranger pickup truck he'd converted with an electric motor and I thought: hmm, this isn't actually as expensive or difficult as I thought, maybe I should do a conversion...

The weight breakdown is something like this: the RX-8 is about 3,000 pounds stock. The rotary engine is about 300 pounds with all its accessories attached. The dual-shaft version of the Netgain Hyper9 AC motor I'm using is 130 pounds. The exhaust system is maybe a hundred pounds or so removed. The gas tank is another hundred pounds or so (when full). I'm adding about 450 pounds of lithium iron phosphate batteries, which gets me about 27kwh and maybe 100 miles of range if I'm lucky. (Used Tesla cells have a lot better energy density and are actually reasonably priced, but they wouldn't have fit very well in the places I wanted to put them. They're also a bit more dangerous than LFP cells and require liquid cooling.) I'm also adding in some weight for battery boxes and the motor mount and motor/transmission adapter. In the end I figure the car'll be about 200 pounds heavier or so, and most of that weight is very close to the ground.

Thanks for all that detail! I hope you’re writing this up somewhere sometime where more people will see it :-). Especially after it’s done it would be cool to read about how it is, how it went, the battle scars and or tips and what you would do next time.
I haven't posted anything publicly yet, but it's on my to-do list.
I'm wondering if these batteries will maintain their capacity over time. I think part of the appeal of traditional battery packs is you can replace them as they wear out and hold less charge. If they do degrade, hopefully a chassis/ battery replacement won't be too expensive.
I've seen estimates that put modern battery at the expected age/mileages comparable to ICE expected lifetimes - at 300-500k miles you usually replace the car anyway, especially modern ones with so much electronics inside, those will probably get outdated way faster
Cars? Probably not.

Drones? Military drones or aircraft? (The paper mentions ARL) Quite possibly. What this promises is that anywhere you would have a strut or panel made from carbon fiber as a load-bearing element, you can have it store some energy for you as well.

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> Cars? Probably not.

Why not cars?

Because structure makes up a small percent of an electric car mass and batteries make up a big percent of electric car mass.

Let's say that it's 10% for structure and 30% for batteries.

If you decrease energy density of batteries several times now they take up let's say 90% of the car mass and the only thing you saved was 10% :)

10% for structure might be an underestimate. I did a Google and it suggested 25% for suspension and chassis and another 25% for body. Obviously that includes more than what you could make a battery, but I reckon it’s more than 10%.

Also, even if it’s only 10% weight you are saving, that sounds pretty good to me!

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When the battery needs replacement, what do you do?

You toss the car in a landfill and stamp out a new one in the factory.

So probably better for drones and things that have a short lifetime anyway.

Drones not likely. Their improved stiffness of 75 gpa is 2x less than carbon fiber.

So you could literally make the frame 2x lighter with carbon fiber and put that 50% of weight in batteries getting you 2x+ more capacity.

Cars more likely as it's roughly on par with aluminum. Still the cost will be way more than plain aluminum or even steel body.

Doesn't the carbon fibre argument work for cars as well? CF is becoming increasingly common and affordable, as are normal batteries.
Some supercars have a carbon frame. But it's extremely expensive. Check maclaren cars for example
BMW i3 has a carbon body, and it's only a little (twice?) more expensive than a normal car. A lot of inexpensive carbon fiber bicycles are available now, while previously you could only get them for big money from big brands. Carbon fiber has gotten cheaper, we're going to see it in a lot of products.
Even more interesting for aviation industry.
> You can't make a car by building the chassis out of smartphone batteries

They're called Structural batteries (or [micro]structural super/ultracapacitors)

"Carmakers want to ditch battery packs, use auto bodies for energy storage" (2020,) https://arstechnica.com/cars/2020/11/carmakers-want-to-ditch...

This is literally what TFA is about
The Ars article I linked has an overview and some history and specific industry applications; whereas OT is about a new approach discovered since the Ars article was written.
Note that Tesla Cybertruck is using battery pack as a structural element.
The battery pack yes. The batteries? I would guess not.
It’s a step in that direction others haven’t made yet.
You comment is more useful than the article, just so you know.
Having the chassis of the car be the battery seems problematic. Once the battery is worn out the whole car must be disposed of.
What about bicycles?
Leads to a lot of potential if the support structure is also the battery. Even as you said, if you have to still have more of it, you don't add weight to store a charge, and if you already need a lot of structure, you're fine.

Having said that, the car chasis is not juuuust about holding up a roof and the humans inside. You also have to handle impact stresses, you don't want it discharging on the poor inhabitants as the car is being hit, etc.

This sounds like a step, out of many, the the direction of lighter cars or aircraft that are electrically powered. It also doesn't have to be the only tech. If we can eliminate say 20% of the battery weight by making the frunk/trunk casings out of this material, some other inner parts of the car, we can use it as part of the solution.

I'm not understanding, perhaps you can enlighten me. The article says "The battery has an energy density of 24 Wh/kg, meaning approximately 20 percent capacity compared to comparable lithium-ion batteries currently available." But the article goes on to say, "since the weight of the vehicles can be greatly reduced." If you need 5x the weight of this kind of battery than if you used Li Ion battery, and a Li Ion battery constitutes 1/3 the mass of a car (at a guess), how is there any savings? Seems like the result will be even heavier than current EVs.
> It's 10 times more everything, just like every other battery breakthrough in the last several decades.

Has the article been changed since you posted this comment? Because the article I've seen was pretty clear:

"Its multifunctional performance is ten times higher than previous structural battery prototypes. [...] The battery has an energy density of 24 Wh/kg, meaning approximately 20 percent capacity compared to comparable lithium-ion batteries currently available."

A battery strong enough to be a structural component, at the cost of 80% of its capacity-per-unit-weight, doesn't sound so hard to believe.

Even the term "massless" is kind of silly. "Structural" should be sufficiently descriptive as most people can infer that if you build the structure out of the material you don't incur any ADDITIONAL weight penalty for the battery (assuming the mass/strength characteristics of the battery are similar to other structural material).
The article explicitly states that is comparing against other prototypes of massless storage, and that energy density is 20% of lithium ion batteries. It then goes on to explain why they still think it is a breakthrough.
You didn't read the article carefully. One of the things it mentions is that it is 20% less energy dense than lithium ion. Sounds terrible, but the upside is you make the car chassis out of battery, so you haven't added weight to it. The net result could be very good, or maybe they need to work on it and improve on the 20%.

Going further with the battery news cynicism idea, batteries have steadily improved over the last 50 years, to an amazing degrees, because of steady breakthroughs causing small improvements. It is why we can have iphones and tesla today.

5x less dense is 80% less dense.
"5x less" would be "x - 5x" or -4x, which of course is nonsense as density can't be negative. "5x as sparse" works if you define sparsity as the inverse of density.
Don't be so weirdly picky.

"times less" is division.

Which inconsistency do you prefer?

• "90% less than x" does not equal "10% of x"

• "90%" does not equal "0.9 times"

• "0.9 times less" means multiplication and subtraction (x - 0.9x) but "1.1 times less" means division (x / 1.1)

This is one of those cases where we know from the context what was meant but that isn't the same as what was said. Normalizing this abuse of language introduces unnecessary special cases and discontinuities for readers/listeners to deal with and creates ambiguity in situations where one of the two interpretations is not so obviously wrong as it is here. It's better to keep the rules simple: ratios, percentages and "times" always involve multiplication by the original value, and "more" and "less" refer to addition and subtraction. There should be a deterministic 1:1 correspondence between the phrasing and the formula.

Does anyone actually say "zero point ___ times less"? I would say not to do that, and only use "times less" with numbers above 1.

That's much easier than dealing with people who calculate percentages wrong or say ambiguous things about large increases.

No, for ratios less than unity most people would use a shorter, more convenient fraction ("nine-tenths") or percentage ("ninety percent") which has exactly the same meaning as the decimal ratio ("zero point nine times"). For fractions the word "times" may be implied rather than explicit; for percentages it's always implied, whereas for decimal ratios it's necessary to distinguish ratios from absolute quantities. These forms are nonetheless all equivalent and substituting one for another should not change the meaning of the phrase. "X more than Y" means addition, even if X is expressed as a ratio ("three times more than Y" equals "300% more than Y" equals "Y plus 300% of Y" equals "Y plus three times Y"). Analogously, "X less than Y" means subtraction, not division, whether X is an absolute quantity, a percentage either less than or greater than 100%, a fraction, or a decimal ratio.

This is human language, of course, so you can be as over-complicated, inconsistent, and ambiguous as you want and generally count on sufficiently smart listeners/readers to decode the resulting mess into something intelligible based on context. It's not good style, and it encourages innumeracy and presents math as being more complicated than it should be, but it will usually get the job done.

> 20% less energy dense than lithium ion

That's 20% as dense (1/5 the density), not 20% less dense (4/5 the density).

As for replacing the chassis—a Tesla Model S has 1,200 lbs of batteries, and the aluminum chassis weighs 410 lbs. Assuming this new material replaces the aluminum pound-for-pound, that would store enough energy to displace about 82 lbs of ordinary lithium ion batteries for a ~5% reduction in total weight. If the energy density were somehow on par with lithium ion then it would save 410 lbs, or 25% of the total weight.

I understand your skepticism (or maybe cynicism). These kinds of articles have been coming out for years. Usually it's some research group in some University that improved on some narrow aspect of the particular part of material science they focus on and then wildly extrapolate the benefits (with the help of media) ... like here where they say: "Super light electric bikes and consumer electronics could soon be a reality" ... I'm sure this 'COULD' be a reality. Will it though?
Dont forget, it the battery still needs replacing eventually. Oh, its in the structure of the device?

Well that sucks. Talk about planned obsolesence.

Seems like making it part of the mass of the car results in a lot of waste when the car is eventually retired as it would probably be hard to separate anything recyclable.
"heavy on assertions", I'm going to remember that one. That's a good bottom line characterization to ask oneself.
I'll re-write it so it's 20% lighter on assertions.
Also, "ten times better than all previous versions." So how good were the previous versions?
I wonder how this compares with Tesla's upcoming structural batteries. They're also supposed to eliminate unnecessary material by making the battery itself a part of car's structural chassis.

https://electrek.co/2021/01/19/tesla-structural-battery-pack...

https://techcrunch.com/2020/09/22/future-teslas-will-have-ba...

This literally is a structural battery. Says that in the first sentence. This is about making a structural battery that’s 10x more efficient by using carbon fiber. How it compares to Tesla is obviously unknown since both are technically vaporware. The concept does sound revolutionary though so hopefully the engineering pans out.
I would give the OP the benefit of the doubt that they understand both are structural batteries and is wondering how they compare in other battery metrics.

From this article, Tesla's blow these ones away - except possibly as a structural element - and they're much closer to being a real product.

I tried but this phrase stood out to me:

> They're also supposed to eliminate unnecessary material by making the battery itself a part of car's structural chassis.

That implies they're believing the article isn't talking about a structural chassis. Why are you treating this like a fanboy competition? It can both be true that Tesla is coming to market with a real product & that this announcement is an important advancement in the state of the art for structural batteries. They are totally different ends of the spectrum with the latter portending where the tech may be heading whereas the former is focused on proving that it's ready for large scale prime time.

> That implies they're believing the article isn't talking about a structural chassis.

"The're also" The use of the word also means they fully understand that both are structural.

> Why are you treating this like a fanboy competition?

WAT?

> It can both be true that Tesla is coming to market with a real product & that this announcement is an important advancement in the state of the art for structural batteries.

Why not? If we take Tesla's statements at face value, it does seem like they intend to reduce weight by using the battery cells between two sheets of metal to function sort of like corrugated cardboard and provide structural support to the frame - as opposed to just being dead weight.

If we look at this article, these guys have made a battery using carbon fiber and fiberglass to make a material that can store energy and provider structural support.

Why would you think only one can be true? They're independent.

To add to that, what Tesla apparently calls structural battery means integrating the battery enclosure into the chassis, whereas this research means integrating the battery chemistry itself.
Tesla's structural battery is production-ready and will be used first in the Berlin-made Model Y, with the new 4680 cells.
Since everyone is highly skeptical of this, is there an alternative to Lithium ion batteries that is close to production currently?
This is a lithium-ion battery. About half of the technologies cited as "replacements" for Li-ion are actually different Li-ion chemistries. Cf. Li-S, "graphene", "nanowire", "solid-state batteries", etc.

Sodium-sulfur batteries are in production currently and can compete on density with Li-ion, but lithium is cheaper and the cost trend is expanding the gap. Silver oxide likewise (silver is expensive!). We do have alternatives, but we don't have good reasons to use them.

Funny that the usability study pop-up doesn't fit on my screen in landscape orientation and totally breaks the site since I can't dismiss it.
My take is that there is some good science and engineering being done here, so we should look past the marketing-speak. I could totally see carbon fiber cylinders of this material landing in a future bicycle, and I do see an eBike in my future.
This may be rather naive but wouldn't using an energy storage mechanism for structural purposes be a bad idea?

That could mean that every fender bender now risks igniting the hood of your car.

sounds like a great idea for consumerism.
At 24 Wh/kg, it's going to take a lot of this to produce an amount of storage relevant to the needs of a vehicle, and that's ignoring the very high cost of the material.

For instance, the Alfa Romeo 4C had an (expensive) all-carbon tub that weighed 65kg. At this storage efficiency, that's only 1.5 kWh... about enough to drive 5 miles in a standard-size vehicle.

Interesting nevertheless, but I can't see getting excited at this density just yet, even if it is true.

It is infinitely greater than 0 anyway. You need the chassis in any case, right? I think this is not meant as a replacement but as a complement of other parts.
"about enough to drive 5 miles in a standard-size vehicle."

Are you accounting for the fact that the alpha romeo would no longer have the mass of a separate battery pack? Might it be 10 miles?

Still needs improvement! Would it work out better in something like an aptera?

If this worked would it be compatible with wireless communication? I know hardly any EE, but I wonder, if there are a bunch of currents in your component housing doesn't that mean it will be hard for an internal antenna to send and receive?
I understand and value the skepticism but for those who wants the science behind their claim, please read their paper "A Structural Battery and its Multifunctional Performance"(also referenced in the article).

https://onlinelibrary.wiley.com/doi/10.1002/aesr.202000093

I'm thinking "backing, bracing, encasing" solar cells... wondering about interactions with heat and insulation; they used to sell "precast wall panels" that were aluminum over foam and cool to work with. This might be "powerwall" bait.
> Funding has come from the European Commission's research program Clean Sky II, as well as the US Airforce.

Carbon fiber structural battery would be ideal for aviation.

Of course, scientific discovery is not the same as engineering solution, this is just early stage research.

I like how they call out that it has 20% of the capacity of a lithium ion battery of the same mass. I'd rather be realistic about technological advances, and then be pleasently surprised when it shows up in consumer products rather than have a glowing press release and then we don't see it in production ever.
I wonder about performance/capacity over time as the material is stressed/flexed. If its structural, it'll take mechanical load. Thin films may not thrive.
My concern with structural batteries is that if your battery wears out (like all batteries before) then you not only need a battery replacement but also a replacement of your cars subframe or underbody. I think this would lead to cars being even more disposable.
And what about small dings? If it's anything like e.g. a li-ion battery, just a small ding will already cause a short. In the best case, that panel will no longer work as a battery. Worst case it starts a fire.
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My main concern would be about reusability. Current battery tech is quite limited with respect to how many charging cycles it supports. So do we need to throw away a bike with structural battery pack then in future, once the charging cycles have expired or someone forgot to regularly keep the battery charged?
perhaps the title should reflect that this is not a regular battery per se, but a structural battery, i.e, a battery that can give mechanical integrity.
In applications where the battery is only providing auxiliary power, such as for bicycles this would be really neat.
A thought.

Imagine working and spending your entire scientific career on a specific problem, hoping to create positive change and then to be meet with this type of skepticism. I can't help but feel sad for everyone involved in this scientific research if they end up seeing this.

I do value skepticism but it feels somewhat unfair here because they are very transparent with how they relate to current existing lithium-ion technology while discussing their differences and how they could potentially innovate and iterate on their solution. All of of this while referring to their peer-reviewed paper.

What more could they have done? Shouldn't we celebrate events like this?

> What more could they have done?

Oh this one is simple. Be transparent in your communication about the limitations of what you've done. Be clear whether this is early research or something likely to find its way into products any time soon. And above all: Avoide terms like "breakthrough" unless they're really deserved (which is exceptionally rare).

But it isn't the researchers doing this. This is university PR.
All of that was clear in the article. It is research, it has way less energy density than a normal battery, and it WAS a breakthrough.
It might not be a breakthrough that takes us to Mars, but saying that an 10x improvement over existing versions isn't a breakthrough feels a bit unfair and a bit narrow minded. In this space it's obviously an breakthrough, you just don't happen to be interested or directly affected by it.
We continue to disseminate this type of news by linking to university press releases or technology news sites rather than the paper directly.

90% of the time press releases oversimplify results and overstate the research impact when the actual paper strives to be on point and accurate.

I appreciate it's hard to stay true to the original research and explain things in a simple but engaging way. On the other hand it sometimes feel like creative freedom in second hand reporting does more harm than good.

Strongly agree, but my experience is that linking to papers directly usually means your thread will die with only a few comments; most people don't want to put in the effort to read the paper and many either don't read or quibble with the abstract. Also, a lot of business websites and Github pages are fluffy and PR and boring academic papers don't stand out well by comparison.

Sadly commercial logic means that most third party science news reporting reverts to a sensational mean because there isn't that much money in accessible-but-serious journalism. Scientific American used to occupy a sweet spot of being informative yet accessible, but as the market at that spot shrank they watered down the quality of their coverage, and that was over 20 years ago. Quanta seems like the best online science writing in recent years but at the cost of fairly limited scope.

I totally feel that. But it's OK. It's only HN. There's plenty of places to feel hopeful about the future and optimistic. Research departments are one place. Your own head could be another. Maybe some of reddit. Some blogs. And like minded people in atomspace.

HN values "intellectualism" so it has to be very cautious to throw its unbridled enthusiasm behind something new that it doesn't understand, unless it turns out wrong. The memory of being wrong, and having to face that stupidity or ignorance I think is too much for the intellectual HN superego to bear, so instead it hedges toward caution and skepticism. These are the default and "sensible" positions if you value not being wrong, and seeming right, and if the cost of "looking stupid" is too perceptually high.

I'm not being too bearish on HN. The flipside is you can have great informed discussions, with less noise and fluff than elsewhere. But you can't find people so readily welcoming of brave new worlds here. They are here, it's just that the community sentiment / mass consciousness / superego of the place shames and punishes any such enthusiasm that isn't backed by hard facts and Wikipedia pages and common knowledge, etc. And even then it's not on the whole welcomed as much as scrutinized, pushed-back against, cross-examined and interrogated. So that's a reaction limiter on those voices speaking up here enthusiastically. Hey, they still do tho. Me included.

I disliked it at first, and extreme examples I still dislike. But I get it's just someone else's way of engaging or seeing the world. That's a valid perspective, just as much as mine. Even if I don't share it. It doesn't matter. Different perspectives are normal.

And I find the awareness I now have of how the HN organism might react to some post a useful different perspective. I don't temper my enthusiasm for new stuff with it, but before posting here, maybe I'll consider how people might react. Maybe they won't be able to appreciate it.

But at the same time. HN is not homogenous. It's amorphous and ever changing. The superego sentiment shifts, and there can be many examples of HN embracing the new.

Given all that, it's good to see voices actually seeking to engage more enthusiastically and openly with newness emerge from the codified skeptical pit that is HN. I think this picture that I paint above misses alot of the details and it probably only 61-62% accurate but it's a fair enough take on HN that I think might clarify some things for people, and certainly does for me.

Tho honestly in the case of this article I would love to see more technical analysis and less skepticism (or meta posts like mine). I know I'm contributing to that, I'm just not skilled enough in this area right now to analyze it, but would love to read discussion of the technical details.

Excellent description of the HN mentality. Many are so afraid of false positives they'll do a middlebrow dismissal of everything. "Actually, XYZ isn't that great because..."

https://news.ycombinator.com/item?id=24613148

And that's a great concise way to say it! I suppose if I were smarter or a better writer those are the exact words I would come up with. Many are so scared of false positives they do a middlebrow dismissal of everything. exactly, Hahaha! Thanks :)
University press releases are often just that bad, especially the ones that lead to papers getting this kind of attention. And this kind of dramatic overselling does deserve all this skepticism.
Please don't take my skepticism for a lack of enthusiasm!

In this case we have an article on a paper - peer reviewed or otherwise - and it's claims.

- data is limited, even taking everything they say at face value.

- my expertise is near nonexistent (like most here)

- predicting the future is hard

- past is littered with "battery breakthroughs" that has not perceptably(this is important distinction) changed life as we know it

So... skepticism it is.

I am absolutely glad this person got to do that science research.

I applaud the work taken to get here and wish all the best for them plus a bottle of [favoured beverage] on top.

I absolutely hope so much more research is done.

But until I perceive data that says otherwise, my skepticism of THIS particular article and it's ability to change any part of the world I am aware of (IE my own, my friends, my family, my social groups) remains.

In future, if a work colleague comes to work one day and says "I was affected positively by [structural battery thing]." New data = new judgement of super awesome cool!

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The relatively low energy density means it won't be replacing li-ion batteries in vehicles any time soon. Where I could see this technology shining is in low-power consumer electronics. For example, since it's flexible, it could be used to make an e-ink reader that's paper thin and flexes (somewhat) like paper.
I've been interested for awhile in how structural computing could be done in this vein. Generally less important for cars right now, but as self-driving technology evolves, I imagine auto manufacturers may become increasingly interested in how to tuck away enough processing power without sacrificing an entire trunk.
There's an article in German that is very critical of the comparisons they make:

https://www.golem.de/news/akkutechnik-das-maerchen-von-der-m...

Essentially the author argues that a comparison with state-of the art cells would mean that they achieve only 8-10% of the capacity per weight of conventional cells. There's a bunch of other specific criticisms in there about comparisons made in the paper.

If I remember correctly Tesla already has plans to incorporate their next gen batteries into the structure of the car
Batteries are a kind of semiconductor. They're bigger than others, but still semiconductors.

Most kinds of semiconductors have a stage in the history of their development where their cost / performance ratio does am exponential Moore's - law plunge. Batteries could get there. So, all sorts of research are good.

In the meantime, maybe this kind of tech could be used to combine PV solar panels with electrical storage.