New Electrode Lets Batteries Charge In 10 Seconds

Al writes "A new lithium-ion electrode allows batteries to be charged and discharged in 10 seconds flat. Developed by Gerbrand Ceder, a professor of materials science at MIT, it could be particularly useful where rapid power bursts are needed, such as for hybrid cars, but also for portable electronic devices. In testing, batteries incorporating the electrodes discharged in just 10 seconds. In comparison, the best high-power lithium-ion batteries today discharge in a minute and a half, and conventional lithium-ion batteries, such as those found in laptops, can take hours to discharge. The new high rate electrode, the researchers calculate, would allow a one-liter battery based on the material to deliver 25,000 watts, or enough power for about 20 vacuum cleaners."

Comments

20 vacuum cleaners...

[Anonymous Coward]

...how many libraries of congress per square inch is that, again?

Re:20 vacuum cleaners...

[NeverVotedBush]

I don't think the ability to drain the battery in such a short time is the point. It's in delivering high current easily.

Lots of loads pull a lot of current initially or periodically. One example would be an electric motor since they talk about applications such as hybrids. The stall current is limited by the resistance of the windings but once it spins up, reverse voltage in the motor limits the current to much lower values. If it was a motor under a heavy load, the current could be much higher.

Another point is that in any high current circuit, the power wasted in the circuit as heat can be very high. It's current squared times resistance. With batteries that have a high internal resistance, that power heats the battery and is also power that's wasted. With a high current delivery capability, these would have very low internal resistance and under heavy loads, the batteries would run cooler and would be able to deliver more power to the actual load instead of throwing it away as heat.

This really is an accomplishment and a valuable one.

Just to illustrate battery self heating - if you ever get stranded in extreme cold because your battery doesn't have the power available to turn the engine over, just turn on the headlights for a while. It's a medium load but will heat the battery from the inside due to internal resistance and make the battery better able to start the car. This really works.

Re:20 vacuum cleaners...

[Snowblindeye]

what the heck is the point of a battery can run 20 vacuum cleaners, for only 10 seconds?

But it also means that you can *charge* it in 10 seconds. How nice it that. One problem for plug-in electric cars is that they take long to charge. If charging it doesn't take longer than filling up a tank of gas, that would be a step forward.

Re:20 vacuum cleaners...

[hardburn]

Fast recharge and discharge go hand-in-hand. This will particularly improve the range of electric/hybrid cars, since regenerative breaking is limited right now by how fast the battery can take in all that power.

I don't see it improving the overall charge time of a car from a household plug, though. The limit there is that 120VAC just isn't enough. You can double up a circuit to get 240VAC, and in fact high draw appliances (like electric dryers) often already do in the US.

If dealerships are smart, they'll contract the services of local electricians to put a 240VAC plug in customers' garages and roll the cost into the overall financing.

Re:20 vacuum cleaners...

[camperdave]

What are you going to plug your charger into?

How about the slow charge, high drain battery bank in the basement. You know, the one that's being charged by the solar panels on the roof and the wind generator in the back yard. Oh, and occasionally off the grid, during off peak hours.

I'm kidding. When I go off the grid, I'll be finding a nice piece of land with good sized waterfall, and setting up a micro-hydro system.

Re:20 vacuum cleaners...

[chrysrobyn]

Perhaps there could develop a market of special charger stations at the intersection of roads whose purpose was to provide you with energy in exchange for money. These special stations might have access to energy storage banks whch they can charge as needed and charge your batteries using a higher current plug than consumers might ordinarily pay for. As time progressed, maybe they'd sell drinks, snacks and half rotten hot dogs.

Re:20 vacuum cleaners...

[fractoid]

Um, for starters, you're not going to be plugging all those cars in at the same time if each one's only plugged in for 10 seconds.

Secondly, generally EV-sized batteries are fast-charged by using a 'dump pack', an identical fully charged pack of batteries that can supply as much current as the flat one can eat up. The important number is the continuous current draw, not peak.

That's what makes small, high-current batteries so good. Imagine a car window motor which pulls, say, 5 amps at 12 volts. You need to run 5amp wiring to it. But assume that the motor only needs to run for a few seconds at a time, very infrequently - instead of running 5 amp wiring, you can simply put a battery next to the motor that's sufficient to run it for a minute or so, and trickle charge the battery over the car's CAN bus.

Another use (actually this is one I read about where ultracaps are useful) is making a hard drive that doesn't lose data when the power drops during a write operation. Basically the cap would store enough energy for the drive to detect loss of external power, finish writing its buffer, and park itself before it ran flat.

20 vacuum cleaners for 10 seconds?

[DigitalReverend]

That sucks.

Good for cars?

[NaCh0]

Great, by the time I have backed out of the driveway I'll need to recharge it.

Re:charging

[yincrash]

after reading the article, fast charging has not been developed. the article writer only says that it may be possible, w/o citing any source regarding that claim.

Re:fast enough for a

[sgbett]

first thought?

Railgun

Boom!!!

[owlnation]

Where does the heat go on rapid discharge?

Or is this the Sony method of rapid discharge?

c'mon, boys

[Anonymous Coward]

a page of comments and no one has yet said:

"10 seconds? the average /. geek discharges faster than that"

sigh.

Re:c'mon, boys

[cbiltcliffe]

That's because in order to prove the conclusion, they'd have to have done the experiment......

Re:charging

[AnotherBlackHat]

>Sure, as long as you can find a 25000 watt outlet.

I don't think so...

Typical Miles per kilowatt hour is 4.
A 100 mile fill-up = 25 kilowatt hours = 90,000,000 watt seconds.
If you want that in 10 seconds, you'd need a 9 Megawatt outlet.

Armageddon

[GottliebPins]

Wow, now we can expect to see spectacular laptop fires hot enough to burn through an engine block. Where can I get some of those batteries? Sony?

Think about it

[jeffmeden]

Actually, the big thing about electric driving isn't getting started in the first place, it's reclaiming the energy when you have to stop (at least for inner city driving.) If you have a battery that is bordering on a supercapacitor to dump energy into, you can reclaim nearly all of the stopping energy into the battery to use to start again. Given that there are 745 watts/hp, a battery capable of a charge rate of 25KW gives you 33 horsepower of braking capacity with one cell. Get 3 of them in a car and you can reclaim 100hp during a stop, which would be good for all but the most grueling emergency stops (depending on the weight of the car).

Re:Think about it

[iksbob]

A 100hp generator weighs 1500 pounds.

Really? I assume you're including the substantial weight of a diesel engine to drive said generator, as a quick google search turns up the Winco EC75PSB4G-17 - a 75 kilowatt emergency backup generator head (just the part that turns shaft movement into AC power) that weighs in at 605 lbs. That's a unit intended for stationary use, not to be mounted to a vehicle. I'm sure a similar device intended for mobile use could be constructed from less massive materials.
In fact, may I direct you to look over the specifications page for the Honda FCX Clarity: link. There you will find that power from the vehicle's fuel cell stack and lithium ion battery is converted to motive force by a 100kW (134 hp) AC electric motor with integrated transaxle. While the page lacks a weight listing for said motive unit, I doubt it exceeds 400 lbs.

My laptop was better

[Alain Williams]

My last laptop battery was faster than this after a few years, it would completely discharge in 5 seconds, not a slow 10 seconds!

Re:fast enough for a

[momerath2003]

You probably would want capacitors for those, with other pulse-shaping devices. In fact, this is what they actually do. Ten seconds of discharge is way too slow for a rail gun.

Re:charging

[Repton]

All you need is a wall socket that can deliver 25,000W!

Note to self: pick up some 100A fuses on the way home.

Re:fast enough for a

[sgbett]

I thought of writing I disclaimer saying as much, but my submit button discharged too fast.

Re:fast enough for a

[rsborg]

I thought of writing I disclaimer saying as much, but my submit button discharged too fast.

You know they have drugs for that. The blue pill and all.

Star Trek inches closer

[Mr Z]

Anyone else notice this from the article?

To improve the batteries, the researchers modified an electrode material called lithium iron phosphate . . . The models suggested a way to improve conductivity by directing lithium ions toward particular faces of crystals within the material.

To exploit this, Ceder included extra lithium and phosphorus. This helps form a layer of lithium diphosphate, a material known for its high lithium-ion conductivity.

Wouldn't it be something if someone trademarks this use of lithium diphosphate on targeted crystal faces as, oh, I dunno, dilithium crystals?

First, transparent aluminum, and now this!

Re:fast enough for a

[rubycodez]

but for a man-portable railgun, the batteries are used to charge the capacitors, all in the back pack.

Wrong analogy...

[NotQuiteReal]

You should think more along the lines of a Beowulf Cluster of Roombas.

Re:charging

[Rufty]

In the fuse draw of a local college electronics lab I found a length of 6inch nail lovingly cut to length with cleaned ends, painted round the middle with the designation "10000A, slow-blow" (Apparently one of the techs had a dead scope that couldn't be powered up - it just blew the fuse. Hence the nail. Bung it in and now you know where the hard short *was*. It's the melted patch with the smoke coming out...)

Re:1.6 Horsepower vacuum cleaners?

[Muad'Dave]

I've never heard of a 10A circuit or receptacle. Many outlets in the US are supplied via a 20A branch circuit using #12 copper, but are wired with 15A receptacles. This is legal according to the NEC code. The remainder are supplied via a 15A branch circuit using #14 copper. The 15A receptacles have the typical 'I I' look to them. 20A receptacles look more like 'I- I' where the neutral blade has a Tee shape. A 20A plug has the neutral lead rotated 90 degrees, so it'll fit in a 20A receptacle but not a 15A one. Similarly, a 15A plug will mate with a 20A receptacle. This chart shows various NEMA plug and receptacle configurations.