10 ms·
Supercapacitors Batteries charges in seconds without degrading
- Tepix 10y agoSorry for being cynical but I'll get excited only once I can actually buy this latest battery breakthrough, not when it is still X years away.
- gravypod 10y agoCoincidentally they also like to discharge in seconds!
- daveguy 10y agoIs that true? All supercaps? This tech in particular?
- nerfhammer 10y agoAll supercaps. Shorting a charged supercap is vastly more deleterious than shorting a battery or even a dc power supply.
- finnh 10y agoDeleterious or dangerous? (ie, does it hurt the supercap, or the thing shorting the supercap)? "When first I appear, I seem deleterious / But when explained, I'm nothing serious"
- lutorm 10y agoProbably both. The fraction of energy deposited in each depends on how the internal resistance of the cap compares to that of the load.
- deleted 10y ago[deleted]
- nerfhammer 10y agoDangerous. Hurts the thing shorting the supercap and anything in close proximity to that thing
- jhou2 10y agowow, it sounds like it would make Samsung's Note 7 battery problems seem elementary. Who would want to carry a device like that in their back pocket or hand it to kids to play with? Would a good drop on hard pavement or sheet metal cause this thing to go off?
- nerfhammer 10y agoIt's not particularly easier to physically rupture than a normal battery. You would have to smash it hard enough to break apart the device.
- Dylan16807 10y agoAlternatively: All supercaps. They have vastly inferior energy density compared to a battery.
- jonawesomegreen 10y agoShorting batteries is also never a great idea, but supercaps are more dangerous because of their low internal resistance. This video is a good demonstration: https://www.youtube.com/watch?v=EoWMF3VkI6U https://www.youtube.com/watch?v=EoWMF3VkI6U I was working on a controls project where we had large banks of supercaps that would charge up to ~900v. Have to treat those with some respect. However as long as they are kept cool the caps had no trouble being charged and discharged with a couple minute cycle with each bank providing 2kWh of energy. In the particular application I was working on we actually had 17 2kWh banks providing ~34kWh of energy every couple minutes. Would not fit in a cellphone though :)
- Florin_Andrei 10y agoAny capacitor, super or not, has a very tiny internal impedance for DC. So a shortcircuit is liable to max out the current output.
- daveguy 10y agoApparently they are on par with energy density and power density. They are way ahead on cycle stability (30k charges). So that pretty much leaves two things: 1. Charge stability. Does it leak like a sieve even without a load after being charged? 2. Manufacturability. I expect this is the big problem. It's a chemical engineering problem to scale up a "nano" process. The article says it's not ready, but doesn't say what the biggest challenge is going forward. Anyone know this particular supercapacity tech? Or supercaps in general?
- honkhonkpants 10y agoWell they are about an order of magnitude below state-of-the-art batteries in terms of energy density, and about the same distance above batteries in terms of power density. For phones this doesn't seem to make sense unless you want your iPhone to be 3cm thick. Maybe an application with greater power demands?
- john_reel 10y agoCan you explain the difference?
- honkhonkpants 10y agoEnergy density is the energy stored per unit volume or mass. Power density is the same thing, but per discharged per unit time. It is essentially a volumetric statement of the internal resistance of the battery or capacitor. Supercapacitors can be discharged very quickly compared to batteries of the same size, but the same sized battery contains more energy.
- bigger_cheese 10y ago>2. Manufacturability. I expect this is the big problem. It's a chemical engineering problem to scale up a "nano" process. The article says it's not ready, but doesn't say what the biggest challenge is going forward. Quoting from the article: "The team at UCF has experimented with applying newly discovered two-dimensional materials only a few atoms thick to supercapacitors. Other researchers have also tried formulations with graphene and other two-dimensional materials, but with limited success." I'm not sure if they used Graphene specifically (the only other 2D matl I know is silicine) but there are manufacturing issues involved with Graphene especially around mass production but these are being solved. Graphene used to be one of the most expensive materials in the world to produce (per unit weight). It is now (2015) "only" about $100/kg. compare this with something like thermal coal (another carbon based matl) at under $100/t. There is still orders of magnitude in the price before economics look good. edit: That is not to say it is worthless the price has fallen fast in last 5 years it just needs to keep at the same trajectory for a while longer. Graphene is after all an extremely new material. I don't think there is anything fundamentally impossible to solve manufacturing wise and economies of scale should kick in as demand for it increases.
- gus_massa 10y agoThe size of the battery varies from phone to phone, but let's choose 3000mAh as a typical value so the battery is enough for a full day. If you want to charge it in "seconds", let's use 60 seconds as an upper bound. So if the charger has a 100% efficiency, then it has to provide 3000mAh/60sec = 3000mAh * 3600 sec/h / 60sec = 180000mA = 18A. An USB can provide between 0.1A and 0.9A. For comparison, a typical plug in a home can provide 10A. So to charge the phone you will need some big connector, not a tiny microUSB like connector. But it's worse. From the article: > "If they were to replace the batteries with these supercapacitors, you could charge your mobile phone in a few seconds and you wouldn't need to charge it again for over a week," said Nitin Choudhary, a postdoctoral associate who conducted much of the research published recently in the academic journal ACS Nano. To recharge the phone once a week, I guess you will need a 20000mAH battery, and a few seconds is something like 5, so the connector must survive to 1000A, that is a ridiculous current.
- utopcell 10y agoCharging a 3Ah battery in 1 minute would need 180A @ 3.7V (not 18A), or 666W. USB power delivery can provide 100W (5A @ 20V.) I think I'd be happy if I was able to charge a 11.1Wh battery in < 7 minutes.
- Yetanfou 10y agoa typical plug in a home can provide 10A. So to charge the phone you will need some big connector, not a tiny microUSB like connector. Current capacity for conductors depends on conductor length as well as conductor size. Short runs of a given size have a higher current capacity than longer lengths due to the larger losses in larger lengths. Also, current capacity depends on the length of time the current has to be carried: a given length of a given conductor size will carry a larger current for a short amount of time compared to the carrying capacity for a longer duration. While a micro-USB connector will not suffice, the needed connector would not be that much bigger: a 3.5mm jack would suffice to carry 18A for a few seconds given a good socket. It would not be hard to design a plug/socket combination with a high-enough capacity which would fit in a phone. To recharge the phone once a week, I guess you will need a 20000mAH battery I recharge my phone (a Motorola Defy+) once a week. It has a ~1500 mAh battery, the thing is 5 years old. I don't think you'd need a 20.000 mAh battery to be able to keep your phone running for a week unless you plan to use it as a hand warmer.
- kylehotchkiss 10y agoThe scary part is that touching the two connectors of a supercapacitor is an instant discharge. Which might prove pretty dangerous.
- jrockway 10y agoThey have some equivalent series resistance and internal resistance, but yeah, try touching the two conductors of a Li ion cell together. Batteries and bombs are basically the same thing -- store energy and release it very quickly.
- mrfusion 10y agoIf this is true it would be revolutionary right?
- hossbeast 10y agoTrue of the handful of battery breakthroughs that you hear about on a weekly basis
- sandworm101 10y ago>>> Anyone with a smartphone knows the problem: After 18 months or so, it holds a charge for less and less time as the battery begins to degrade. Really? That's still a thing? These aren't nicads. I've found that my phone doesn't report full charge as often, but it still lasts for a similar amount of time. My 5+yo netbook's battery is still reporting 80% of its design capacity. Imho, such apparently dramatic falls in capacity often have more to do with running apps rather than physical degradation of the battery. Talk to me after a reset to factory settings.
- ant6n 10y agoMy three-year-old MBP lasts about an hour. I think it lasted like 6-8 hours at first.
- eon1 10y agoDoes it run the same OS, software, etc as before, though?
- kamilner 10y agoIf it's under warranty, that's worth taking in. When I got my MBP repaired under warranty they also noticed my battery was doing worse than it should for the number of cycles and replaced it no questions without me having to ask. I believe rated is 80% health after 1000 cycles, and mine was somewhere around 75% after 8 or 900---you can check the these values in system information, I believe.
- ant6n 10y agoWarranty was only for a year. I had it repaired at some point for some heatsink issue, and they offered they could swap out the battery while at it (i.e. no extra labor). But it would've cost me 300$ CAD just for the battery, which seemed expensive at the time. Now I regret not paying for that..
- vvanders 10y agoNo, it has to do with temperature. Li charged when cold/hot will significantly degrade the battery. See Tesla(with liquid thermal cooling) vs Leaf degradation over the last couple years.
- seesomesense 10y agoThe original article is High-Performance One-Body Core/Shell Nanowire Supercapacitor Enabled by Conformal Growth of Capacitive 2D WS2 Layers DOI: 10.1021/acsnano.6b06111 and is available at the usual places.
- AndrewDucker 10y agoI thought that capacitors also discharged incredibly quickly. Can a capacitor be used like a battery?
- dragontamer 10y agoMost capacitors are measured in "micro"Farads. Supercapacitors are measured in Farads, and the capacitors mentioned in this article are likely reaching kilo-Farads.