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How a Microscopic Supercapacitor Will Supercharge Mobile Electronics

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Re: How a Microscopic Supercapacitor Will Supercharge Mobile Electronics

#11

Post by pavs »

ridgeguy wrote: post #10
mey wrote: post #5

Earlier quoted context omitted.

This is true of all energy storage. Your laptop lithium-ion batteries are pretty decent fire starters when shorted correctly (incorrectly?). This is why there is so much safety circuitry in batteries. https://www.youtube.com/watch?v=HCGtRgBUHX8 Another way to think about it is to compare Energy Density to larger scale things we have closer experiences with, such as Gasoline https://en.wikipedia.org/wiki/Energy_densit…

Agree - rate of energy release is everything. A pound of hamburger releases about 1152 kcal, or about 4.8 megaJoules of energy when metabolized over a day or so after it's eaten. One pound of TNT releases about 2 megaJoules of energy in a few microseconds when it's detonated. Big difference in the results. One makes me fat. The other makes me dead. I'd be worried about a super capacitor that contained a week's worth…

> Big difference in the results. One makes me fat. The other makes me dead.

Well both makes you dead, but at different rate...

Re: How a Microscopic Supercapacitor Will Supercharge Mobile Electronics

#12

Post by p1mrx »

astrodust wrote: post #2

What's especially remarkable about this process is how they're using an every-day piece of electronics, a Lightscribe, a DVD burner basically, to do the production. They need a laser with precision control and where better to find one than in a device like that.

LightScribe was discontinued in 2013, and is no longer available on new drives. It's fortunate that someone thought to try this experiment during its brief window of popularity.

Re: How a Microscopic Supercapacitor Will Supercharge Mobile Electronics

#13

Post by aexaey »

jws wrote: post #4

Together with a battery, such supercapacitors could run a cellphone for days. Really? That's novel. One of the proposed applications is for bursty current applications which currently have batteries with more capacity than required in order to serve peek current demands, but I rather doubt cell phones are in that category.

s/peek/peak/

Re: How a Microscopic Supercapacitor Will Supercharge Mobile Electronics

#14

Post by ChuckMcM »

mey wrote: post #5
ChuckMcM wrote: post #3

I was talking with someone about this the other day, the amount of energy you can store in graphene capacitors (potentially) is pretty impressive. The trick is not turning them into bombs at that point. I expect that we'll see a lot more in this space over the next 6 to 18 months. Perhaps it was what Elon was eluding too with his range statements.

This is true of all energy storage. Your laptop lithium-ion batteries are pretty decent fire starters when shorted correctly (incorrectly?). This is why there is so much safety circuitry in batteries. https://www.youtube.com/watch?v=HCGtRgBUHX8 Another way to think about it is to compare Energy Density to larger scale things we have closer experiences with, such as Gasoline https://en.wikipedia.org/wiki/Energy_densit…

Not exactly.

Batteries store energy in a reversible chemical process. In so doing their ability to discharge that energy is limited by the rate at which that reaction can occur internally. The reaction is exothermic so the batteries get hot and sometimes catch on fire. Lithium ones are particularly nasty as the materials are reactive with oxygen in the air so once the battery begins to disassemble itself the additional reactions are started.

Capacitors on the other hand simply store charge. There is no chemical process involved and so their internal resistance is much much lower (it is basically the metal conductivity of the plates and the wires to the plates). So a capacitor with with the equivalent of 2mJ of charge, can release it all in picoseconds. [1] Such an energy release would be indistinguishable by people observing it from any other high explosive detonation. Further is would have no warning, batteries at least get hot, then start smoking, and then catch on fire. This would simply consume what ever conductor had shorted it and immediately turn it into a raging ball of plasma.

[1] I once considered a supercap as a "fun" battlebots weapon with the 'fork of dooooom' which when it hit your bot would vaporize that section.

Re: How a Microscopic Supercapacitor Will Supercharge Mobile Electronics

#15

Post by astrodust »

p1mrx wrote: post #12
astrodust wrote: post #2

What's especially remarkable about this process is how they're using an every-day piece of electronics, a Lightscribe, a DVD burner basically, to do the production. They need a laser with precision control and where better to find one than in a device like that.

LightScribe was discontinued in 2013, and is no longer available on new drives. It's fortunate that someone thought to try this experiment during its brief window of popularity.

Finding these used would not be hard.

Re: How a Microscopic Supercapacitor Will Supercharge Mobile Electronics

#16

Post by jmichelz »

ridgeguy wrote: post #10
mey wrote: post #5

Earlier quoted context omitted.

This is true of all energy storage. Your laptop lithium-ion batteries are pretty decent fire starters when shorted correctly (incorrectly?). This is why there is so much safety circuitry in batteries. https://www.youtube.com/watch?v=HCGtRgBUHX8 Another way to think about it is to compare Energy Density to larger scale things we have closer experiences with, such as Gasoline https://en.wikipedia.org/wiki/Energy_densit…

Agree - rate of energy release is everything. A pound of hamburger releases about 1152 kcal, or about 4.8 megaJoules of energy when metabolized over a day or so after it's eaten. One pound of TNT releases about 2 megaJoules of energy in a few microseconds when it's detonated. Big difference in the results. One makes me fat. The other makes me dead. I'd be worried about a super capacitor that contained a week's worth…

Actually the bun (and ketchup) makes you fat. The meat (and fat in it) makes you thin. https://en.wikipedia.org/wiki/Why_We_Get_Fat
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