Thursday, March 12th 2009
Re-engineered Battery Material Could Lead to Rapid Recharging of Many Devices
MIT engineers have created a kind of beltway that allows for the rapid transit of electrical energy through a well-known battery material, an advance that could usher in smaller, lighter batteries -- for cell phones and other devices -- that could recharge in seconds rather than hours. The work could also allow for the quick recharging of batteries in electric cars, although that particular application would be limited by the amount of power available to a homeowner through the electric grid.
The work, led by Gerbrand Ceder, the Richard P. Simmons Professor of Materials Science and Engineering, is reported in the March 12 issue of Nature. Because the material involved is not new -- the researchers have simply changed the way they make it -- Ceder believes the work could make it into the marketplace within two to three years.
State-of-the-art lithium rechargeable batteries have very high energy densities -- they are good at storing large amounts of charge. The tradeoff is that they have relatively slow power rates -- they are sluggish at gaining and discharging that energy. Consider current batteries for electric cars. "They have a lot of energy, so you can drive at 55 mph for a long time, but the power is low. You can't accelerate quickly," Ceder said.
Why the slow power rates? Traditionally, scientists have thought that the lithium ions responsible, along with electrons, for carrying charge across the battery simply move too slowly through the material.
About five years ago, however, Ceder and colleagues made a surprising discovery. Computer calculations of a well-known battery material, lithium iron phosphate, predicted that the material's lithium ions should actually be moving extremely quickly.
"If transport of the lithium ions was so fast, something else had to be the problem," Ceder said.
Further calculations showed that lithium ions can indeed move very quickly into the material but only through tunnels accessed from the surface. If a lithium ion at the surface is directly in front of a tunnel entrance, there's no problem: it proceeds efficiently into the tunnel. But if the ion isn't directly in front, it is prevented from reaching the tunnel entrance because it cannot move to access that entrance.
Ceder and Byoungwoo Kang, a graduate student in materials science and engineering, devised a way around the problem by creating a new surface structure that does allow the lithium ions to move quickly around the outside of the material, much like a beltway around a city. When an ion traveling along this beltway reaches a tunnel, it is instantly diverted into it. Kang is a coauthor of the Nature paper.
Using their new processing technique, the two went on to make a small battery that could be fully charged or discharged in 10 to 20 seconds (it takes six minutes to fully charge or discharge a cell made from the unprocessed material).
Ceder notes that further tests showed that unlike other battery materials, the new material does not degrade as much when repeatedly charged and recharged. This could lead to smaller, lighter batteries, because less material is needed for the same result.
"The ability to charge and discharge batteries in a matter of seconds rather than hours may open up new technological applications and induce lifestyle changes," Ceder and Kang conclude in their Nature paper.
This work was supported by the National Science Foundation through the Materials Research Science and Engineering Centers program and the Batteries for Advanced Transportation Program of the U.S. Department of Energy. It has been licensed by two companies.
Source:
MIT News Office
The work, led by Gerbrand Ceder, the Richard P. Simmons Professor of Materials Science and Engineering, is reported in the March 12 issue of Nature. Because the material involved is not new -- the researchers have simply changed the way they make it -- Ceder believes the work could make it into the marketplace within two to three years.
Why the slow power rates? Traditionally, scientists have thought that the lithium ions responsible, along with electrons, for carrying charge across the battery simply move too slowly through the material.
About five years ago, however, Ceder and colleagues made a surprising discovery. Computer calculations of a well-known battery material, lithium iron phosphate, predicted that the material's lithium ions should actually be moving extremely quickly.
"If transport of the lithium ions was so fast, something else had to be the problem," Ceder said.
Further calculations showed that lithium ions can indeed move very quickly into the material but only through tunnels accessed from the surface. If a lithium ion at the surface is directly in front of a tunnel entrance, there's no problem: it proceeds efficiently into the tunnel. But if the ion isn't directly in front, it is prevented from reaching the tunnel entrance because it cannot move to access that entrance.
Ceder and Byoungwoo Kang, a graduate student in materials science and engineering, devised a way around the problem by creating a new surface structure that does allow the lithium ions to move quickly around the outside of the material, much like a beltway around a city. When an ion traveling along this beltway reaches a tunnel, it is instantly diverted into it. Kang is a coauthor of the Nature paper.
Using their new processing technique, the two went on to make a small battery that could be fully charged or discharged in 10 to 20 seconds (it takes six minutes to fully charge or discharge a cell made from the unprocessed material).
Ceder notes that further tests showed that unlike other battery materials, the new material does not degrade as much when repeatedly charged and recharged. This could lead to smaller, lighter batteries, because less material is needed for the same result.
"The ability to charge and discharge batteries in a matter of seconds rather than hours may open up new technological applications and induce lifestyle changes," Ceder and Kang conclude in their Nature paper.
This work was supported by the National Science Foundation through the Materials Research Science and Engineering Centers program and the Batteries for Advanced Transportation Program of the U.S. Department of Energy. It has been licensed by two companies.
71 Comments on Re-engineered Battery Material Could Lead to Rapid Recharging of Many Devices
A name of school has to be capitalized. Just like your first and last name.
Even Wikpedia has "Arcane School" capitalized at least 6 times. Cant argue with English language.
No seriously, what is so difficult to understand for you? OK. By steps:
1 - Any energy conversion has a loss. If 50w are being produced, after the conversion the ammount will ALWAYS be lower. The factor between the input and the ouput values is called efficiency.
2- In your suggested setup there is an extra unnecessary conversion of energy types. Specifically mechanical to electrical conversion = gas/diesel engine -> dynamo -> battery
3- After that, the electricity needs to be transformed into mechanical energy (movement) once again: the electric engine.
Where do you see any benefit there? I'll put it with an example: an hybrid car with 50kw power each engine. We are going to use the gas engine to feed the batteries as you suggested.
- The electric engine produces 50kw of power and propels the car.
- The gas engine produces 50kw as we have stated, and it charges the battery with a dynamo. As I hope that we already have understood, that conversion has a loss, so although the engine produces 50kw, only 30kw are tranferred to the batteries.
- Hence all the time that the car is running, it is spending 70kw (50+20) and using only 50kw for propelling the car.
A normal hybrid would use the gas engine only when required and if the batteries get empty it will be used to, but all the time to it's full potential, hence producing more movement for the same ammount of eergy produced, which is the same as the ammunt of fuel used.
About the arcane school. It's not a name!! :laugh:
Or maybe I'm wrong. You usually said: "Hey, mom I'm going to School?" "I'm attending the Summer School""Kids must go to School""I'm talking about the Big School with White Doors that is in the main road to the left, not the Small School In The Other Side"?
If the new battery material is truly efficient as it states, then it will only take 0.3KW to recharge it.
Prius battery holds 300 watt/H.
Thus my idea using a small generator that produces 5500W/h is more then adequate.
But even if it uses the new extended battery package, that is 5000W, plus new battery material, you would only need 5KW to recharge it.
Thus a small house generator would suffice, even though it produces 6.5KW at 50% power.
My math is not exact at this given hour, but calculations in general will suffice.
We still dont know how fast a new battery material will decrease charge time on a car battery, that is the key ingredient we are missing from final equation.
Anyways, not seeing the correlation between using combustion to charge a battery while idling, or while in motion? I'd imagine it would automatically kick in at the most opportune moment...
This new batteries will not allow to charge batteries using less energy, they will only allow for faster charges. Batteries can only take a defined amount of power at a time, no matter how much power you give them: you give them 1000w and they will only take 250w. This new ones will allow them to take all. But the amount of energy that the batteries hold won't change too much and it doesn't matter if it does improve, the best way of recharging them will always be using the electricity coming from a power plant and probably the worts one using a small generator.
And its not a bad idea to use a fuel powered engine to recharge the battery. Every hybrid manufacturer does it. Other wise they are wrong and you are right. Perhaps you should take all their jobs? :rolleyes:
It saves you gas by letting it idle and you DO use less fuel when you are idling vs driving at X MPH....
Your car has three sensors...idle, normal speed, highway speed and adjusts the injection nozels accordingly. Your gas pedal is really an "air pedal" by pressing your accelorator you open the airway sending more air to the fuel air mix causing a bigger explosion -combustion- in your engine..because you delievered more air your vehicle also needs slightly more fuel.
By idling instead of turning your car off not only are you saving fuel but your not burning your starter, putting wear and tear on your engine...you see when your car is off the oil leaves the engine compartment and pools down in the oil pan. once you go to start your car your engine has to cycle a few times before the oil is circulated through your engine once again lubricating the parts. When you initially start your car the air intake sucks in a huge amount of air (and extra fuel) to initially get your engine going and then it settles into idle....so by turning your car off and on in a short amount of time not only do you experience more wear and tear but you use more fuel in a simple application.
Also idling is in no way hard on an engine due to the low load, low rpm and much lower thermal loads experienced. Accelerator on the floor, max rpm - that's what is hard on an engine and uses a lot more fuel.
2- Hybrid car manufacturers DON'T use the gas engine to charge the batteries. They use them for movement along with the electric engine. Batteries are charged when the car stops from movement.
3- A car in movement doesn't have to perform all those tasks you mention in order to start. because it's in movement it doesn't need any extra fuel to start off, indeed it requires less than later when it will be propelling the car. It neither needs to stop oil delibery, etc. The engine is "working", moving all the time, but without any fuel inside. Off doesn't mean still. Just like when you push the car to start it off when the starter or the battery is wrong.
I'm starting to think you lack any basic knowledge required to understand this, but think of it this way: using a gas engine to recharge the battery, is like having one battery charging another battery. It will never be able to charge the second one to the level of energy it was holding (loss in the transfer remember?), so it's just better to use that battery directly instead of using it to charge the other. It's exactly the same (albeit aggravated) in the case of the gas engine and battery.
I think that what you didn't understand is that an idling engine will never create the same energy as one running at full rpms. It will always create less than the one it would be able to develop if used to propel the car. BTW I hope at this point that yu know that a gas engine is more efficient when running at around 2000-3000 rpm (diesels 1600-2500 rpm) and NOT when theyare idling. Efficient = kw/liter
And the more load you put on the engine the more fuel it uses, thus your equation just flew out of the window.
Learn how an engine works first before you make up numbers out of air.
Of course the more load you put on the engine the more fuel it uses, but wait, take a seat, this might take you by surprise: the more load you put on the engine, the more power it gives!! :twitch: OMG!! That... can't... be... true!!
But hold on, and take some breath before we continue...
...that's it, you are prepared already...
... and? ok: the more power the engine gives...
...the better it moves the car!!
So, for efficiency, you take the power it gives or the movement it produces and you factor in it with the fuel (or energy) it consumes and there you have, efficiency factor. :)
This is going to be your homework:
-Take a read: www.autospeed.com/cms/A_110216/article.html
- Learn a fact or two from there.
- Look at the efficiency charts. (HINT: BSFC the lower the better)
- Return and make a coherent post. Keep the nonsense away.
Anyway, all that doesn't have anything to do with the topic, and neither has to do with your idea. No matter how efficient the fuel engine is, it will always be a waste of time and fuel to use it to charge a battery that at the same time is used to feed another engine. A waste. I don't know what's so hard to understand for you, but I'll say it in just another two ways:
1- Your idea is like having a bicycle with an electric engine that you have to pedal more to charge the batteries than what you would have to pedal to move the bicycle.
2- Is having a gas engine with an autonomy of 1000 km only charging a battery with enough energy to drive 750 km. You lost 250 km.
Advice to you. learn the language first, learn to read, then construct your arguments accordingly to each topic in specific, DONT ASSUME... and stop jumping all over the place.
Showing me charts of LAB tested engine is WAY different then in real world environment.
If you take same exact engine, put them in 5 different cars, then your charts go out the window.
As i said, and its written in the page that your provided, that your efficiency is not 2000-3000RPM, it can be as high at 6000RPM. Its all writen in that page to which you posted a link to.
Also where you put the engine means nothing for what we are discussing, we are discusing an engine feeding a battery, not an engine propelling 5 different cars. :shadedshu
Ever watch MPG computer that most cars have now? Drive down the highway, reach the speed of your Efficiency RPM, then put the car in neutral, GAS efficiency/economy doubles if not triples.
Pus we dont know exact "LOAD" that will be put on the engine when it is idling. Or did you miss that as well? Showing me two charts of small engines that drive the car, is way different then connecting it to generator that will charge the battery. There is fuel efficiency and there is BPH efficiency. Two different things.
And that LeMans Engine that was in the link, is 9K RPM. Look at your own charts. NOT 12k, ... 9K. Thus according to your theory or your math, it should be at 4.5k, because its 9k RPM Engine.
BPH can also change fuel efficiency and fuel economy in the same exact car.
Edit.
Here is a simple read. www.allpar.com/mopar/new-mopar-hemi.html
It states many time that engine efficiency has changed with change of an engine design and engine components. There are no graphs, because real world environment cant be shown on a graph.
The above is, once again, the same thing that I've been saying all the time. At idle the engine consumes less (I never said the contrary), but it also works less. In fact it works much less, and because of that the efficiency is lower at such low rpms.