Could you have a bunch of them and draw from them in sequence?
Comment on New breakthrough may let us charge smartphones in 60 seconds
Thevenin@beehaw.org 4 weeks ago
Yeah, no. This is not about chargers or batteries or phones or cars. This study is about improved charge/discharge rates for supercapacitors.
Supercaps have very high flow rate, but extremely low capacity. Put them in a phone or a car and it would run very fast for five minutes. Supercaps are useful, don’t get me wrong, but they’re not batteries.
Very cool research from UC Boulder, but the journalism leans way too far into clickbait.
cygnus@lemmy.ca 4 weeks ago
brie@beehaw.org 4 weeks ago
Increasing capacitance (how much charge is stored to reach a certain voltage) or the voltage it is charged to would indeed increase the capacity. Putting several in parallel would work, as would making a bigger capacitor. The main problem as far as I can tell is that the energy density of even supercapacitors is low, so you’d need a much larger volume to have the same capacity (and thus a much thicker phone).
cygnus@lemmy.ca 4 weeks ago
Thanks for this - I was doing some reading in the meantime which confirms what you’re saying about power capacity.
en.wikipedia.org/wiki/Capacitor_electric_vehicle
As of 2010, the best ultracapacitors can only store about 5% of the energy that lithium-ion rechargeable batteries can, limiting them to a couple of miles per charge.
Thevenin@beehaw.org 4 weeks ago
Yeah, this matches my experience.
A supercapacitor buffer will cost around twice as much and deliver around 1/10th the watt-hours of a similarly-sized lead acid battery. And lead acid isn’t exactly great to begin with.
Capacitors are useful, but only in applications where the total amount of energy stored is more-or-less unimportant.
TonyTonyChopper@mander.xyz 4 weeks ago
The bigger issue I would see is the heat created from dumping all that energy in at once. And can a US outlet even provide that much power?
Thevenin@beehaw.org 4 weeks ago
Solid point. A laptop battery is around 60Wh, and charging that in 1 minute would pull 3.6kW from the outlet, or roughly double what a US residential outlet can deliver.
Supercaps stay pretty cool under high current charging/discharging, but your laptop would have to be the size of a mini fridge.
The research paper itself was only talking about using the tech for wearable electronics, which tend to be tiny. The article probably made the cars-and-phones connection for SEO. Good tech, bad journalism.