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Lithium batteries charge ahead - Researchers demonstrate cells that can power up in seconds.
Nature News ^ | 11 March 2009 | Geoff Brumfiel

Posted on 03/11/2009 1:43:13 PM PDT by neverdem

Two researchers have developed battery cells that can charge up in less time than it takes to read the first two sentences of this article. The work could eventually produce ultra-fast power packs for everything from laptop computers to electric vehicles.

Byoungwoo Kang and Gerbrand Ceder of the Massachusetts Institute of Technology in Cambridge have found a way to get a common lithium compound to release and take up lithium ions in a matter of seconds. The compound, which is already used in the electrodes of some commercial lithium-ion batteries, might lead to laptop batteries capable of charging themselves in about a minute. The work appears in Nature1 this week.

Lithium-ion batteries are commonplace in everything from mobile phones to hybrid vehicles. "They're essentially devices that move lithium ions between electrodes," says Ceder. The batteries generate an electric current when lithium ions flow out from a storage electrode, float through an electrolyte, and are chemically bound inside the opposing cathode. To recharge the battery, the process is reversed: lithium ions are ripped from the cathode compound and sent back to be trapped in their anode store.

The speed at which a battery can charge is limited by how fast its electrons and ions can move - particularly through its electrodes. Researchers have boosted these rates by building electrodes from nanoparticle clumps, reshaping their surfaces, and using additives such as carbon. But for most lithium-ion batteries, powering up still takes hours: in part because the lithium ions, once generated, move sluggishly from the cathode material to the electrolyte.

Tunnel vision

That seemed to be the case for lithium iron phosphate (LiFePO4), a material that is used in the cathode of a small number of commercial batteries. But when Ceder and Kang did some calculations, they saw that the compound could theoretically do much better. Its crystal structure creates "perfectly sized tunnels for lithium to move through", says Ceder. "We saw that we could reach ridiculously fast charging rates."

So why hadn't anyone seen this speedy charging in practice? Ceder and Kang theorize that the lithium ions were having trouble finding their way to the crystal structure's express tunnels. The authors helped the ions by coating the surface of the cathode with a thin layer of lithium phosphate glass, which is known to be an excellent lithium conductor. Testing their newly-coated cathode, they found that they could charge and discharge it in as little as 9 seconds.

"As far as I know, this is the fastest yet for this material," comments Peter Bruce, a chemist at the University of St Andrews, UK. The researchers do not know exactly how the disordered glass helps lithium ions transfer between the electrolyte and the cathode.

Other materials, such as nickel oxide, have achieved similarly fast charging rates, says John Owen, a chemist at the University of Southampton, UK. "This is a nice demonstration of the concept in a lithium system," he says. Lithium, though, can store more energy for less weight than nickel compounds, and holds its charge better.

It's particularly important because lithium iron phosphate is already being used commercially, adds Bruce. Speeding lithium ion movement would vastly improve energy recovery in hybrid vehicles, which recharge their batteries when the vehicle brakes — a process that lasts only seconds. It could also eventually lead to fully electric vehicles that could charge reasonably quickly.

Ceder says that he thinks that improvements in modelling will allow researchers to find other candidates for ultra-fast batteries. "My guess is that there are more materials like this out there," he says.

TOPICS: Culture/Society; News/Current Events; Technical
KEYWORDS: batteries; battery; lithiumbatteries; lithiumbattery
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To: Publius6961
Methinks many posters on this thread need to watch this useful video...

Physics for Dummies

21 posted on 03/11/2009 2:20:29 PM PDT by Publius6961 (Change is not a plan; Hope is not a strategy.)
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To: ak267

Throw in a flywheel, Solar panel on the roof, boiler and triple expansion steam engine and a sheep to supply methane (with ‘proper fittings’) and you will have the most complicated car ever.

22 posted on 03/11/2009 2:21:46 PM PDT by Dinsdale
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To: Dinsdale
Lots of people have such a device today.
It's called a welder...

: )

23 posted on 03/11/2009 2:23:05 PM PDT by Publius6961 (Change is not a plan; Hope is not a strategy.)
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To: Publius6961; Dionysius

Toyota claims that not one has required a battery replacement due to malfunction or “wearing out.” The only replacement batteries sold—at the retail price of $3000—have been for cars that were involved in accidents. Toyota further claims that the nickel-metal hydride (NiMH) battery packs used in all Prius models are expected to last the life of the car with very little to no degradation in power capability.

24 posted on 03/11/2009 2:25:16 PM PDT by rawhide
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To: rednesss

“one might think that that the speed at which it can be charged is also the speed that it can be discharged.”

I think you are correct. This means a massive amount of energy could be discharged very quickly if there is a short circuit. It seems to me that this would present a Hindenberg-like risk of catastrophic failure.

25 posted on 03/11/2009 2:26:29 PM PDT by Texan Tory
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To: Publius6961

So - only conservatives could get them? :-0

26 posted on 03/11/2009 2:28:15 PM PDT by HeadOn (Lord, please save us from Socialism.)
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Comment #27 Removed by Moderator

To: neverdem

They need to patent it elsewhere, sell the rights in some other country, and move to some other country, before Obama taxes them for being “lucky.”

Leave now!

28 posted on 03/11/2009 2:30:12 PM PDT by MeanWestTexan (Beware Obama's Reichstag Fire.)
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To: rawhide
I knew that. I was being sarcastic.
I have wasted way too much time arguing with ignorant idiots who, to this day, not only claim the absurd $10k figure, but go on to claim when you get rid of a Prius you need to pay a $20k+ "pollution fee."

A neighbor replaced his at 140,000 and somehow he talked Toyota into installing it at cost; under $2500.

29 posted on 03/11/2009 2:31:23 PM PDT by Publius6961 (Change is not a plan; Hope is not a strategy.)
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To: El Gato; Ernest_at_the_Beach; Robert A. Cook, PE; lepton; LadyDoc; jb6; tiamat; PGalt; Dianna; ...
Half of Black Teens May Be Vitamin D Deficient

New drug shows benefits against nasty asthma It sound's like a monoclonal antibody. It's probably not cheap.

Vitamin C May Help Prevent Gout

FReepmail me if you want on or off my health and science ping list.

30 posted on 03/11/2009 2:34:23 PM PDT by neverdem (Xin loi minh oi)
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To: Publius6961
That would be one heck of a welder.

You are underestimating the potential current coming out of this battery.

BTW you can arc weld with a bunch of jumper cables, eight or nine car batteries and a coat hanger as welding rod. It won't be pretty but it can get you off the trail.

Shorting this battery wouldn't make an arc welder, it would make a bomb.

Electric potential turns to heat, heat turns parts of battery and bus bar to plasma...

31 posted on 03/11/2009 2:34:50 PM PDT by Dinsdale
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To: Red Badger

Do they run down at the same speed as they charge ?......:o)

32 posted on 03/11/2009 2:36:29 PM PDT by Squantos (Be polite. Be professional. But have a plan to kill everyone you meet)
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To: Moonman62

A battery that can totally discharge in 9 seconds by definition moves a lot of energy in a short period of time. Thus it will deliver a lot of energy when it is shorted out. Should this short occur inside the battery between the + and the - components, yes it might blow up or catch fire.

33 posted on 03/11/2009 2:55:03 PM PDT by theBuckwheat
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To: rednesss
Good question, one might think that that the speed at which it can be charged is also the speed that it can be discharged.

Holy mackeral! Don't ever short the suckers out!

34 posted on 03/11/2009 4:18:32 PM PDT by Ole Okie
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To: Ole Okie

35 posted on 03/11/2009 4:23:28 PM PDT by rednesss (fascism is the union,marriage,merger or fusion of corporate economic power with governmental power)
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To: neverdem
This thread is too good to pass up.

I have a Dell laptop which contains a 2300 mA-hr battery (or 2.3 A-hr). 2.3 A-hr is the amount of energy that a fully-charged battery contains and is equal to 8280 A-sec. If I bring the battery from fully-discharged to fully-charged in 9 seconds at a constant charging current, I would need to supply 8280/9 A or 920 amps to the battery for 9 seconds. Furthermore, this 920 amps times 14.8 volts represents 13,616 watts power for the 9-second charge time. Mucho amps and lotsa watts!

How big would the connecting wires need to be to carry this huge current? The largest gauge copper wire in the American Wire Gage standard is number 0000 which is 0.46 inches in diameter and is rated for 380 amps; you would need to connect 3 of these huge wires to each battery terminal to keep from exceeding the wire current-carrying capacity. Of course that much current would vaporize the terminals.

The 920 amps is DC but it could be converted from house current AC by using a power supply. A 120-volt wall circuit can supply 15 amps maximum at 120 volts or 1800 watts. Clearly, if you need 13,616 watts and only 1800 watts is available from your friendly local wall socket, you would come up short. If I got AC from the heftiest circuit in my home breaker box (30 amps at 240 volts), that would provide only one-half of the power needed to charge my laptop battery in the 9 seconds!

Of course, if I ran 920 amps into my laptop battery it would explode. Period.

Someone brought up the Prius. My sister has a Prius and I checked the owner's manual which lists the auto's specifications. According to my calculations, the Prius can run on the battery pack for only two minutes! The gas engine has to almost constantly start, run, and stop to recharge the battery. Her car does get an honest 45 MPG which I attribute to two factors: The engine runs at a constant speed to charge the battery pack (at optimum efficiency) and the Prius wheel motors turn into generators when you slow down, using the car momentum to recharge the battery pack.
36 posted on 03/11/2009 5:01:08 PM PDT by normanpubbie
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To: normanpubbie

You mean your electric range or electric dryer is not on a 50AMP breaker?

37 posted on 03/11/2009 5:06:33 PM PDT by MHGinTN (Believing they cannot be deceived, they cannot be convinced when they are deceived.)
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Thanks. I double-checked and I do have a 50-amp breaker on my range circuit.

It takes my Dell battery about 3/4 hour (2700 seconds) to go from fully discharged to fully charged using the stock AC power supply. That implies that at 100 percent charging efficiency the battery is charging at close to 1 amp. This is a far cry from a 9 second recharge at a 920 amp charging rate.
38 posted on 03/11/2009 6:45:50 PM PDT by normanpubbie
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To: normanpubbie

Yup, lots of hype in the article.

39 posted on 03/11/2009 6:53:35 PM PDT by MHGinTN (Believing they cannot be deceived, they cannot be convinced when they are deceived.)
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To: neverdem; AdmSmith; Berosus; Convert from ECUSA; dervish; Ernest_at_the_Beach; Fred Nerks; ...

thanks neverdem.

University of Miami physicist develops battery using new source of energy
His discovery is a ‘proof of principle’ of the existence of a ‘spin battery’
University of Miami | Mar 11, 2009 | Unknown
Posted on 03/11/2009 5:30:26 PM PDT by decimon

Breakthrough battery can charge up in seconds | March 12, 2009 | Mark Henderson
Posted on 03/11/2009 4:41:38 PM PDT by Free ThinkerNY

40 posted on 03/11/2009 7:31:25 PM PDT by SunkenCiv ( Profile updated Monday, January 12, 2009)
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