Lithium Iron Phosphate batteries charge up in seconds

Interesting article just up on the BBC News website:

BBC NEWS | Science & Environment | Battery that 'charges in seconds'

This is about an article lifted from Nature magazine:

Lithium batteries charge ahead : Nature News

About new research from 2 researchers at the Massachusetts Institute of Technology in Cambridge.

By changing the chemicals in Lithiun Ion batteries they can get them to charge up much faster and they don't decay as fast.

This sounds very promising

This battery technology is promising because it has been extensively produced and proven. Remember the recently launched BYD's F6DM PHEV ?


[ame=http://en.wikipedia.org/wiki/Lithium_iron_phosphate_battery]Lithium iron phosphate battery - Wikipedia, the free encyclopedia[/ame]

After seeing the BYD at the Detroit Auto Show I hope the battery is better made than the rest of the car. She's a bit rough mate.

Well, no one is saying that first step will always be pretty, especially for 1st timer automaker like the BYD

Don't think BYD Pat,think Prius...with that battery!!

The problem to be solved, then, is not how fast the battery can take a charge but how fast the charge can be delivered. Even with a 220V connection at 50 amps, you are only talking 11 kWh per hour. So for a full range EV with say a 50 kWh battery, it is still 5 hours to charge (this is essentially the specs for the Tesla). In order to transfer 50 kWh in a few minutes you would need one hell of an electrical connection.

This would be a breakthrough for house batteries on boats and RVs. Our boat uses a large gel cell lead acid battery to supply power for lights, music, radios, and such. When connected to shore power, the house battery is charged by a 100A smart charger, which, in theory could charge the battery completely in about two and half hours. In practice, of course, it takes much longer.

The problem is the charge curve of normal batteries. The house battery can take 100A for only a very short time while the surface of the plates are recharging. Once the surface is recharged, the chemical process has to penetrate deeper into the plates. The deeper the penetration, the slower the process. This leads to an asymptotic charge curve, where you start with fast charging and taper off to nothing over time.

Left connected to shore power, the asymptotic charge curve is not a problem. Under way, while cruising, it is a pain in the behind. We have a 100A marine alternator on our diesel engine, so once again in theory you could charge the battery fairly quickly, but in practice the charge rate drops with time to a point of diminishing returns. It doesn't make sense to idle a diesel engine for hours trying to get that last bit of charge. In practice, while cruising, you only charge your battery to about 85%. This limits the useful capacity of the battery, forcing you to carry a larger battery.

With one of these new quick-charge batteries you could recharge as fast as available power allows.

Tom

posted this on the "liquid battery" thread.

its a very promising start, although there are technical issues to deal with like how to charge the batteries. even with batteries as small as the ones used in cellphones, its was still drawing 350 amps.

so they need to figure out a way to slow it down or modify it to charge slower. its great that they have potentially eliminated most of the danger issues with Li by virtually eliminating the overheating issues.

You can always charge slower. That's easy to do: just supply less power. Charging faster is the trick.

Tom

a large capacitor that is trickle charged would be a good idea as well. a series of them that can dump charge their load would be something worth looking at

I wouldn't go that far. This technology has been around since the mid 1990's. Recent work on micro surface preparation has promised much better performance

Ideally you'd use super caps or liquid battery technology to allow the charging station to quickly charge the battery without undue strain on the intertie grid system

It's like large university laser experiments that rely on capacitor banks that charge overnight, or at least an hour. In theory, when the laser discharges it would require more power than is possible from a major grid intertie

I get excited just imagining the curve ....

Seriously, that's why normal batteries eventually sulfate up, as the charge can't be kept "perfect" on the battery. In practice, 80-85% is "full" charge for a battery

I was surprised in the cranking performance, and increased life, of the batteries on my equipment just by using a Battery Minder with desulfator

Bingo. Most of our current battery chemistries can already be charged way faster than we can practically deliver the current. This "charging in seconds" is meaningless in a large format pack. You will not soon see a 300-mile battery car that can practically be charged in just a few minutes. A couple of hours - way more likely. And most of our battery chemistries can already handle that.

The smart charger on our boat has that built-in. Our current house battery is a decade old, where many boat owners only get a season or two from a battery.

Tom

Is this an announcement that the 2010 Prius has a lithium iron phosphate battery?

One of the more interesting and little understood aspect is the Prius battery has a minor impact on the mileage. During the Dept. of Transportation fleet endurance study, they found the battery capacity after 160,000 miles was ~2.5 Ahr from an initial 6.5 Ahr yet the mileage at the end was pretty much the same as the whole 160,000 mile test. There was a 3-4 month interval in the very first months that seems associated with higher battery capacity but we're talking 2-3 MPG increase over the whole lifetime.

There is a common misconception that the Prius is just an electric car with a battery. It more accurate to see it as sophisticated gas car that uses battery power to make up for the weaknesses of the gas engine. When you start thinking this way, you begin to realize what a small roll the battery chemistry plays in the Prius performance. But that is OK.

As long as the 'honorable competition' thinks the battery chemistry is the key technology, they won't see the clever engineering in the Prius. They'll keep trying to make $80,000, battery play-toys.

Bob Wilson

Well said Bob. It is important to keep in mind that as an energy storage medium, batteries or any electrical equivalent have a long way to go to get anywhere close to the energy that is stored in gasoline, whether measured by volume or by weight.

One USG of gas contains 124,000 BTU or 36.3 kW-hrs of energy. Compare that to the 1.31kW-hrs TOTAL capacity of the G2 Prius traction battery pack. So 1 gallon of gas has 27.7 times the energy of the battery pack ... meaning the gas tank, assuming a conservative 10 USG capacity, has 277 time the energy content of the Ni-MH traction battery. Much of this gas energy of course gets lost in producing motive power to the wheels; still, the comparison does illustrate how far battery storage has to progress to be competitive.

that is one way to look at the issue and its most likely the wrong way...

battery tech should only have to come half way, the rest is up to us. we need to face that facts that we need to do a very hard evaluation of exactly what is important to us and to be honest with ya, something that has a 300 mile range is not that important to me when compared to the issues tied to our ignorance of what we are doing to our planet...

heck, even a dog does not sh** in its bed. cant we at least be that smart??