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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

#101

Post by dreamcompiler »

djrogers wrote: post #68
choeger wrote: post #53

Earlier quoted context omitted.

I don't know. Sure, if you can build batteries with the energy density of gasoline, you can build an electric plane with them. But is this really necessary ? Right now, we have relatively large, relatively fast, jet planes. Do we need that size and that speed to be commercially viable? Could we also run a larger fleet of smaller, more automated planes or helicopters? If there was no kerosene left by tomorrow morning,…

> I don't know. Sure, if you can build batteries with the energy density of gasoline, you can build an electric plane with them. But is this really necessary? Only if you value overseas travel... It currently takes ~16 hours to fly from SF to Singapore depending on weather. Any longer, and you're going to see a lot of that travel disappear.

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.

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

#102

Post by Obi_Juan_Kenobi »

0xffff2 wrote: post #60
rocqua wrote: post #6

IF this is true, it would be a massive breakthrough. Truly monumental. Hence, I am skeptical. But otherwise, this would be a massive thing. a 2x capacity per weight advantage of batteries? Without an increase in space? That comes down to doubling the range of EVs, and making electric planes and rockets a lot more viable. A 3x capacity per space advantage means roughly a 3x improvement in your phone and laptop battery…

A 3x increase in density does approximately nothing to make electric airliners more viable. We need more like a 100x increase before we see an electric 737 or A320.

An electric airliner would be able to operate at much higher altitudes, and thus much more efficiently.

Looking only at energy density is naive.

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

#103

Post by goldenchrome »

0xffff2 wrote: post #58
pbhjpbhj wrote: post #35

Earlier quoted context omitted.

>Or, more likely, a slight improvement in your phone and much thinner phones. On laptops, we might see the return of more ports. // Please, no. I don't understand the utility of making something so expensive be so fragile and hard to hold. My phone is 5mm thick, that's already too thin for me. Does anyone want thinner phones or is it just a marketing thing?

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.

It’s not incredibly rare at all. Phones these days are engineered well and they’re much less susceptible to fall damage. I’ve dropped my case-less iPhone X on the ground half a dozen times and it’s only collected a few dings on the corners.

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

#104

Post by simonebrunozzi »

0xffff2 wrote: post #57
DennisP wrote: post #34

Earlier quoted context omitted.

Electric airplanes need significantly better energy density.

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

From what I've read, ONE order of magnitude higher density is all we need for commercially viable eletric airplanes. We don't need an additional 10X, as you are suggesting.

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

#105

Post by bfieidhbrjr »

choeger wrote: post #53
DennisP wrote: post #34

Earlier quoted context omitted.

Electric airplanes need significantly better energy density.

I don't know. Sure, if you can build batteries with the energy density of gasoline, you can build an electric plane with them. But is this really necessary ? Right now, we have relatively large, relatively fast, jet planes. Do we need that size and that speed to be commercially viable? Could we also run a larger fleet of smaller, more automated planes or helicopters? If there was no kerosene left by tomorrow morning,…

> if you can build batteries with the energy density of gasoline

Actually significantly worse than that. A plane gets lighter the longer it flies, especially at takeoff when everything is at max thrust. A battery becomes more and more dead weight the longer you fly.

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

#106

Post by driverdan »

snovv_crash wrote: post #87
driverdan wrote: post #77

Earlier quoted context omitted.

> A 10x speedup of charging? Not possible with existing infrastructure. The limiting factors are cooling the batteries and feeding them enough power. On small scale like laptops it's possible to speed up charging but not at large scale like cars. That isn't to say it may be possible in the future but it isn't now.

It increases the charging speed by reducing the heat produced while charging.

If it makes charging more efficient (less energy converted to heat, more stored) then it would improve the charge rate but not by 10x.

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

#107

Post by Gh0stRAT »

dreamcompiler wrote: post #101
djrogers wrote: post #68

Earlier quoted context omitted.

> I don't know. Sure, if you can build batteries with the energy density of gasoline, you can build an electric plane with them. But is this really necessary? Only if you value overseas travel... It currently takes ~16 hours to fly from SF to Singapore depending on weather. Any longer, and you're going to see a lot of that travel disappear.

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 charging port fails to work for some reason? What about the carbon footprint of these airborne generators?

Plus, now you have the weight of the capacitors to carry around all the time, further reducing the effective payload.

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

#108

Post by Animats »

Bad headline. This increases power density, not energy density of lithium batteries, by decreasing internal resistance. That potentially increases charging speed. They claim by 10x.

Car charging stations are going to need megawatt chargers if this works.

They talk some about the possibility of future silicon batteries using this technology.

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

#109

Post by Animats »

onion2k wrote: post #69
djrogers wrote: post #68

Earlier quoted context omitted.

> I don't know. Sure, if you can build batteries with the energy density of gasoline, you can build an electric plane with them. But is this really necessary? Only if you value overseas travel... It currently takes ~16 hours to fly from SF to Singapore depending on weather. Any longer, and you're going to see a lot of that travel disappear.

Only if you value overseas travel... It currently takes ~16 hours to fly from SF to Singapore depending on weather. Any longer, and you're going to see a lot of that travel disappear. It takes that long because it's more efficient to do it in a single flight. Taking off and landing are a massive waste of time and fuel. If we only had short range planes people would change their destinations in some cases or they'd pl…

In the era when planes had to do that, there was not much trans-oceanic travel. The Pan Am flying boats, the "China Clippers", went from San Francisco to Hawaii to Midway to Wake to Guam to Manila to Macao to Hong Kong. It took a week.[1]

[1] https://tripsintohistory.com/wp-content/uploads/2012/10/Clip...

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

#110

Post by Gibbon1 »

choeger wrote: post #53
DennisP wrote: post #34

Earlier quoted context omitted.

Electric airplanes need significantly better energy density.

I don't know. Sure, if you can build batteries with the energy density of gasoline, you can build an electric plane with them. But is this really necessary ? Right now, we have relatively large, relatively fast, jet planes. Do we need that size and that speed to be commercially viable? Could we also run a larger fleet of smaller, more automated planes or helicopters? If there was no kerosene left by tomorrow morning,…

I keep seeing numbers around 500 miles range floated for 8-12 passenger electric aircraft.

Fire up google earth and start drawing 500 mile radius circles around metro areas.

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