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Vertically aligned carbon nanotubes triple the density of lithium batteries

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Re: Vertically aligned carbon nanotubes triple the density of lithium batteries

#141

Post by AI_WAIFU »

andai wrote: post #138
0xffff2 wrote: post #57

Earlier quoted context omitted.

"significantly" sells it short. Electric airliners need a couple orders of magnitude of improvement to even come close to viability.

Serious question, would nuclear powered planes be viable? As far as energy density goes it seems pretty hard to beat! https://xkcd.com/1162/

They tried that. The problem is shielding the reactor and figuring out what to do in the event of a crash. https://en.wikipedia.org/wiki/Nuclear-powered_aircraft

Nuclear marine propulsion seems much more viable.

Re: Vertically aligned carbon nanotubes triple the density of lithium batteries

#142

Post by Animats »

samatman wrote: post #135
Animats wrote: post #129

Earlier quoted context omitted.

We'll see. They ought to get the power increase, just from using something more conductive. The energy density increase looks like more of a maybe. This isn't the first company to claim carbon nanotube batteries.[1] [1] https://www.chasmtek.com/solutions/carbon-nanotube-lithium-i...

Sure, but your claim was that it's a bad headline, when in fact the headline is reflected in the article. You're shifting the goalposts. Disclosure: I've worked on the software side of the battery industry, and am skeptical of any battery I'm not holding in my hand.

skeptical of any battery I'm not holding in my hand.

Um, yes. Still, this seems to be a reasonable way to go, especially since the developer claims to be able to make layers of carbon nanotubes cheaply.

Nawa, though... They announced in 2019 that they would be shipping ultracapacitors by the end of the year. But their products page doesn't list any. They're not a vendor known to Avnet or DigiKey. They announced a super-bike with ultracapacitor boost in 2019, and there are pictures, but none show the bike in motion.

Re: Vertically aligned carbon nanotubes triple the density of lithium batteries

#143

Post by MauranKilom »

rini17 wrote: post #2

Wow, if the coating is so cheap perhaps it can replace activated charcoal elsewhere, too. Would it also triple the capacity of water filters?

I'm not exactly sure you want carbon nanotubes in your water filter. They are mechanically very similar to asbestos and seem to likewise damage lung tissue. Probably better not to ingest them?

Re: Vertically aligned carbon nanotubes triple the density of lithium batteries

#144

Post by wobbegongz »

andai wrote: post #138
0xffff2 wrote: post #57

Earlier quoted context omitted.

"significantly" sells it short. Electric airliners need a couple orders of magnitude of improvement to even come close to viability.

Serious question, would nuclear powered planes be viable? As far as energy density goes it seems pretty hard to beat! https://xkcd.com/1162/

Yes, both USA and Soviet experimented with nuclear powered planes during the 60s. The problem was how to shield the pilots from radioactivity. https://en.wikipedia.org/wiki/Nuclear-powered_aircraft

They also experimented with nuclear powered drones. https://www.popularmechanics.com/military/research/a33565112...

And Russia now claims to have a nuclear engine that can make a cruise missile fly for days. https://en.wikipedia.org/wiki/9M730_Burevestnik

Re: Vertically aligned carbon nanotubes triple the density of lithium batteries

#145

Post by k_sze »

A bit off-topic, but when you think about it, it’s interesting how our vocabulary is shaped by gravity.

I mean, why “vertically aligned” and not “horizontally aligned”, right? It’s not like the performance of the battery actually changes if you made it stand up or lie sideways.

Why are we expected to picture “vertically aligned” as |||, but “horizontally aligned” as ——, right? Could we have used different wording that is not influenced by our superfluous spatial perception?

Re: Vertically aligned carbon nanotubes triple the density of lithium batteries

#146

Post by AnimalMuppet »

k_sze wrote: post #145

A bit off-topic, but when you think about it, it’s interesting how our vocabulary is shaped by gravity. I mean, why “vertically aligned” and not “horizontally aligned”, right? It’s not like the performance of the battery actually changes if you made it stand up or lie sideways. Why are we expected to picture “vertically aligned” as |||, but “horizontally aligned” as ——, right? Could we have used different wording tha…

We want words to communicate, not to abstract robots or something, but to people. Shared experience helps with that. Gravity is a universally shared human experience. So we use words with that bias without even thinking.

Should we change? Why? They communicate, which is the point of words.

Re: Vertically aligned carbon nanotubes triple the density of lithium batteries

#147

Post by filoeleven »

I’m excited for new battery tech, almost entirely due to my niche interest in powered paragliding.

Electric paramotors require a lot less maintenance than their gas-powered counterparts, which need servicing after every 10 hours of flight. I’d love to buy one, but I am not interested in becoming a two-stroke mechanic.

One of the big names in the sport has said that his only reservation to recommending electrics is their flight time, currently about 45 minutes vs 1.5 hours for gas.

This advance, assuming these motors use lithium batteries, which I haven’t checked, bumps them up to 2h 15m on one charge and makes them more compelling. I thought I’d have to wait a decade to get this kind of gain, so this is pretty awesome news.

Re: Vertically aligned carbon nanotubes triple the density of lithium batteries

#148

Post by datameta »

analognoise wrote: post #71
datameta wrote: post #62

Earlier quoted context omitted.

Granted, not to take away from the point of different use cases, however Sienna is a very small medieval-era town that one can walk across at leisure and the Houston interchange is one of the most complex in the US. So it is somewhat of a hyperbolic comparison. I agree that very common suburban and rural vehicles, respectively, are SUVs and pickup trucks. But I am curious what portion of urban drivers use a vehicle t…

Why would you want a vehicle that only covered 95% of your use cases? It's like condoms - better to have it and not need it than need it and not have it.

It certainly makes sense on a personal level but when one multiplies this thought process by a given population there starts to be a compounded issue of excess material going into the construction of the vehicles, excess fuel being used to move them, and excess parking space used to store them, to name a few.

Re: Vertically aligned carbon nanotubes triple the density of lithium batteries

#149

Post by tatersolid »

Gh0stRAT wrote: post #107
dreamcompiler wrote: post #101

Earlier quoted context omitted.

It's not difficult to imagine in-flight recharging from something like a KC-135 running a big fat generator. If you're recharging capacitors, connect time would probably be a minute or two.

I'm not so sure about that being an acceptable solution for civilian transportation… Even assuming automation can eliminate the risks and training overhead associated with in-flight refueling, there are still be some major hurdles that would need to be addressed before this could be considered a viable solution. The 3 big ones that come to mind are: What happens if the KC-135 misses the rendezvous? What if the chargi…

> What happens if the KC-135 misses the rendezvous? What if the charging port fails to work for some reason?

The same thing that happens today with combustion aircraft: the crew makes an emergency landing if they can, or bails out and waits for a Seahawk to pick them up.

This actually happens with fuel-driven aircraft regularly today.

Re: Vertically aligned carbon nanotubes triple the density of lithium batteries

#150

Post by rocqua »

seanc wrote: post #79
0xffff2 wrote: post #58

Earlier quoted context omitted.

The thinner the phone, the thicker the case I can put on it with the same total thickness. It's incredibly rare to see a case-less phone in the wild these days.

I heard somewhere that in Holland every bicycle + lock weighs 5kg. If you have a cheap 5kg bike no one wants it and you don't have to lock it. If you have an expensive 1.5kg bike you need a lock that weighs 3.5kg to protect it.

You're off by a large amount. I'd say its closer to 15kg, and bike quality and weight aren't that correlated here. It's a lot more about maintenance and not being rusted to hell w.r.t. how likely a bike is to get stolen.

In general, since we are so flat a country, bike weight doesn't matter much. We'd rather have extra fancy stuff on a bike than have a lighter bike.

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