Lithium Air Batteries Get Boost From IBM and DOE 240
coondoggie writes "The Department of Energy and IBM are serious about developing controversial lithium air batteries capable of powering a car for 500 miles on a single charge – a huge increase over current plug-in batteries that have a range of about 40 to 100 miles, the DOE said. The agency said 24 million hours of supercomputing time out of a total of 1.6 billion available hours at Argonne and Oak Ridge National Laboratories will be used by IBM and a team of researchers from those labs and Vanderbilt University to design new materials required for a lithium air battery."
Overstated (Score:5, Interesting)
Current plug-in vehicles? Like, what a Chevy Volt or a hacked Prius? Nonsense. Try a Tesla Roadster, with a single charge range of 250 miles. Lithium-air might double the range then. But a factor of 5? No.
I do have one question though. How are lithium-ion batteries affected by increasing cell size? The Tesla Roadster currently uses a ridiculous number of very small cells in its pack, in a move that looks dictated by ridiculous patent licensing terms limiting cell sizes to those suitable for laptops in an effort to prevent the existence of something like the Roadster. That's what it looks like. But is there a technical reason to limit cell size? There is surprisingly little information available about how the performance of lithium cells change as they get physically larger (or smaller).
Comment removed (Score:2, Interesting)
Fingers Crossed (Score:3, Interesting)
Energy-dense storage media have been the missing link in a lot of relatively clean energy generation schemes. For example, both solar and wind power are challenged by the need to store power for when the wind isn't blowing and the sun isn't shining.
Re:Hopefully not vaporware. (Score:5, Interesting)
Lithium-air is, IMHO, one of the least promising upcoming battery techs. It's really more like a fuel cell, and to be blunt, fuel cells suck. By that, I mean:
* Expensive per watt
* Short lifespans
* Inefficient
There are many, many promising next-gen battery techs other than li-air. Here's just a couple of my favorites.
Lithium-sulfur: This has long been worked on, but only just recently one of its big problems has been worked around. It offers great energy density, but some of the intermediary reaction products -- various lithium polysulfides -- are rather soluble. They'd migrate across the membrane and precipitate out on the other side, being rendered permanently useless to the reaction and thus aging the cells very quickly. Older solutions to try to prevent this caused dramatically lower energy density. The latest technique involves wicking the sulfur into the pores of mesoporous carbon and then functionalizing the outside of the carbon with polyethylene glycol to keep the hydrophobic polysulfides inside when they form. The longevity improvements were amazing, without sacrificing energy density. We're talking that when they deliberately chose a worst-case solvent, one that's really good at dissolving polysulfides, the traditional Li-S cell lost 96% of its sulfur in 30 cycles while theirs only lost 25%.
Nickel-lithium: It is, quite literally, a hybrid NiMH/li-ion battery -- a traditional NiMH cathode that can hold a tremendous amount of lithium, and a lithium metal anode (almost obscene anode energy density). That's normally impossible, since you want to run a NiMH battery with an aqueous electrolyte and your various lithium-based cells with an organic electrolyte. They do both -- they use a new tech called a LISICON membrane to keep the two different electrolytes apart but allow lithium ions across. An additional problem with li metal anodes is that dendrites tend to form that rupture the membrane -- but LISICON membranes are a rigid ceramic that resists dendrite damage.
Digital quantum battery: This is my favorite, because it comes straight out of left field. It's really a type of capacitor. Now, capacitors normally hold a lot less energy than batteries; if the voltage gets too high, you get dielectric breakdown, it arcs across, and your energy is lost. But at very tiny scales, current must move as quanta. So if instead of a single big capacitor, you lithographically print an array of nanoscale capacitors, all of the sudden you can make it so that you essentially can't get dielectric breakdown. In fact, you can store so much energy that the stresses become so great that it's best to use a carbon nanotube for one of the electrodes in each nano-capacitor. :)
And even ignoring next-gen battery techs, there is still *huge* range for improvement in li-ion. In particular, for the cathodes, my favorites are layered manganese cathodes which alternate long-life forms and high energy density forms of magnanese oxides to get both properties; and fluorinated metal cathodes. For the anodes, there's many kinds of tin and particularly silicon anodes out there that store nearly an order of magnitude more lithium than conventional graphite anodes. Silicon anode li-ion cells are just this month starting to hit the market. The tech has finally matured to the point where their longevity is sufficient.
Re:Recharge time? (Score:3, Interesting)
Full charge of a Tesla Roadster, which has a 250 mile range, takes 3.5 hours on a 240 volt circuit at 70 amps. So yes, at quickest supported charging rate, the amperage is quite substantial. Many residential homes in the US have 100 amp service. 200 amp service is probably a good idea for Roadster owners. Charging a lithium-air battery pack with double the capacity might take 7 hours. But it could vary considerably from that guess because battery charge times differ depending on the chemistry and nanoscale structures in the cells. Lithium-air might be better or worse. One supposes part of the research effort is to figure out how to make sure the battery has reasonable charge times.
Re:Recharge time and price bigger issue (Score:4, Interesting)
But how are you going to distribute the power? My house gets 100A at 250V so thats 25000 watts. I doubt the cable in the street can supply that to each house at the same time (car charging time) when the electric stoves are cooking dinner as well. For 100kw we need four times that so at best we need to double the diameter of every cable running along every street and push back higher peak current requirements into the distribution system as well.
I think we are going to need to charge more for high current delivery on top of high energy delivery to encourage slow overnight charging, otherwise the networks and generators won't be able to cope with the demand.
Gasoline's energy density is a fundamental limit (Score:1, Interesting)
Gasoline at 50MJ/kg is pretty much the most dense energy storage possible in this universe excluding nuclear energy. (Hydrogen is 150MJ/kg, and might beat gas, but it needs to be in liquid form. Same range anyway) It exclude the weigh of the oxygen as well.
This is kind of a fundamental limit as to how much energy can be stored in *any* system using potential energy of the electric field of matter. That includes (nano)springs, batteries and small flywheels (flywheels bigger than the earth with relativistic speed could exceed this limit)
You may get 2x better efficiency in an electric motor, but I can not see how a battery can approach this value. A gas tank probably weighs 5% of the fuel it holds, and to build a battery where all infrastructure to support the (very) active material only weighs a few percent of the battery wold be very hard even if you find such a chemistry.
Re:Gasoline's energy density is a fundamental limi (Score:2, Interesting)
The issue here, is how much of the 50MJ/kg is actually converted into mechanical energy via the combustion process, and how much of it is expelled as waste thermal energy out of the tail pipe, and leaked out of the metal skin of the engine?
Since an electric engine is not a thermal engine, it does not have to obey carnot efficiency. Nearly all of the thermal loss comes directly from the resistance of the materials in the battery pack, and in the coil windings and power leads to the motor.
The pedant will argue that the power plant that generates the power which charges the battery pack is a carnot heat engine (Steam turbine in nuclear plant, Steam turbine in coal plant, with exception of water turbine in hydroelectric.), and thus suffers the carnot efficiency limit, in addition to the compounding losses of resistance in trasmission, charging, and operation (making it always net lower than direct gas combustion.) This however totally ignores solar power(Not a carnot heat engine), Wind power (also not a heat engine, unless you get REALLY pedantic, and say that wind is just a natural thermal imbalance in the atmosphere, and subject to carnot efficiency from the sun's heat, which is really stretching it.), and hydroelectric power (also not a heat engine). Also, it does not apply the same way to a geothermal plant, despite being a heat engine (Hot steam, geothermal heat source), since the plant does not burn a fuel (compares apples to oranges.
Thus, the REAL issue is not how much energy is stored in the "fuel", but how much energy in that fuel is actually used to do work. A black hole contains an absurdly high amount of energy per kg, but you cannot get any energy out of it, making it worthless, etc.
Researching lower resistance + higher capacity + lighter weight battery packs, along with the use of very low resistance/superconductive coil windings would do much to push an electric engine above the maximum efficiency of any heat-based engine, simply by reducing the amount of heat produced, potentially by orders of magnitude.
That is to say, you don't NEED to carry around 50MJ/kg of energy, if you get better economy out of your storage system: You can carry more water in a tincan than you can in a 55 gallon barrel with holes poked in the bottom, using the same number of trips. The reason is because the tincan doesn't leak nearly as much as the 55 gallon drum does.
THAT is how an electrical motor can beat a heat engine's efficiency. (assuming you arent filling the tincan using leaky 55 gallon drums, of course; using a coal/oil/nuclear power plant to charge the battery defeats the purpose, since the second law demands that you could never beat direct application using indirect application. The transmission system will ALWAYS incur a loss in addition to the losses of the direct generation at the power plant.)
Thus, what the pedant needs to do is stop thinking in terms of oil being the gold-standard, since that creates circular logic. (If Oil is the gold standard, you can never beat oil.) Instead, you should look at the total effiency as the standard, and aim to beat that. That can actually be done.
Re:Gasoline's energy density is a fundamental limi (Score:3, Interesting)
Gasoline has a lot of energy per volume, no doubt. But an IC engine has a maximum efficiency burning that gasoline of about 40%, real world efficiency is around 20%. Electric motors are 90% real world efficient. Now assuming your 50MJ/kg is correct, all your battery has to do is match 11MJ/kg and it will equal gasoline assuming everything is equal. As noted in another post its not equal, the electric motor weighs almost nothing compared to the IC engine, as a result you need even less energy. According to the article the batteries being researched will be capable of 5.6MJ/kg. That's halfway to the equal comparison. This isn't even considering that cars are designed for 300+ miles per fillup but the average daily use is less than 40milies and the median is less than 20miles.
Electric energy can propel your car for $0.03 per mile. If gas taxes were taken out (I used my states gas tax, yours could be several cents different either direction), you are paying roughly $2.30 per gallon and if you car gets 35mph per gallon you are paying $0.06 cents per mile, that's HALF the cost.
There are so many people that don't realize how game changing the Chevy Volt is. Give it a battery pack that can sustain it for equivalent miles to a gas tank (currently it's 40mph on pure electricity with a gasoline generator backup) at the same vehicle weight and the gasoline IC engine will fade into history. This doesn't even factor in how much funner it is to drive a car with electric drive train, the power and torque curve are identical where in an IC engine they are offset significantly. Car and Driver LOVED the Volt and Tesla Roadster because they are a blast to drive and cheaper to drive than a gas car. It's a win-win for everyone if the battery tech advances to the stage that you can get similar miles from battery pack as from gasoline.
Re:Gasoline's energy density is a fundamental limi (Score:1, Interesting)
Good points!
However, to be fair, you cannot just compare the weight and cost of a gas tank vs. a battery, but, ultimately, you have to compare (gas tank + Motor + radiator + exhaust system + drive train + brakes) vs. (Batteries + one electric motor per wheel).
Plus, electric motors and batteries are almost ideally scalable, meaning a 20kW version will not cost and weigh much more than a fifth of a 100kW version.
Therefore, affordable electric lightweight vehicles for personal transportation at moderate highway speeds (100km/h or app. 65mph) seem doable to me at the same cost as a midsized sedan today, but much cheaper to operate. Imagine no Oil changes, no brake jobs, no timing belt replacements.
You probably won`t be able to use them to haul a trailer with two cows to the county fair, but they will be perfectly adequate to drive to the organic farm 25 miles out of the city to buy two quarts of milk and a dozen apples. Incidentally, that is what most SUVs were used for before they were traded in for a Prius last year.
If, after economies of scale have been at work for a couple of years, we get a battery with 10kWh of useable capacity and 4x5kW peak electric wheel motors for $10.000, then that would translate into a Smart-Car sized vehicle with >100km/65m range with fuel costs of app. 3 Cents per mile vs. fuel costs of 12 cents per mile for a 25mpg at $3/gallon "cheap" car like a Dodge Neon sold for $10K until a few years ago.
If you drive both for slightly over 100k miles, you break even, especially as the much lower maintenance on the electric car would much more than offset the interest for the initially higher investment.
This is good news for people with a home in suburbia. If gas prices continue to rise, they will still be able to afford a car to commute, albeit they probably wouldn't want to drive to disneyland with the family in it.
So I pray to the George Clooneys of this world: Go buy Teslas and a couple of Volts for the kids, so the kinks get worked out quickly, and I can afford a then reliable and cheap Volt V5.0 in 10 years time!
Re:Gasoline's energy density is a fundamental limi (Score:4, Interesting)
Not even close. For example, beryllium blows it away in both volumetric and gravimetric energy density (and hydrogen blows beryllium out of the water in gravimetric comparisons, but sucks at volumetric).
Hydrogen was included in TFA comparison.
No, it isn't. Nor is beryllium. Energy doesn't even have to be stored in chemical bonds (see, for example, digital quantum batteries).
Energy is still stored in the electrical field in matter. A quantum battery needs a lot of infrastructure to handle the forces, so at least 50% of the weight will be wasted. (compare to the weight of a clamp holding a spring.)
Try 4x in typical driving conditions.
No, A small VW diesel has up to 40% efficiency. An elelctric car may have 90%, but you can only use 60% of the battery without damaging it in a few cycles, so overall, 2x is conservative.
It doesn't need to. A motor the size of a watermelon propels the Tesla Roadster from 0-60 in under 4 seconds. In gasoline cars, the fuel is light and the engine is heavy. In EVs, the motor is light and the "fuel" (the battery pack) is heavy. It's a reversed paradigm. You have to compare the mass and volume of the engine + fuel to the mass and volume of motor + fuel. And with current battery tech, you'll find that EVs are about 1/4 to 1/3 of the way to matching gasoline cars. But batteries have increased nearly 5-fold in energy density the past 21 years, and show no signs of stopping.
You are partially correct. A brushless electric motor can have very high intermittent power density. maybe 10x of a gas engine. It is only limited by cooling. For continous power its power density is the same as a gas engine. Maybe a hybrid combination can beat either. It is actually quite complicated to cool an electric motor. Think 100kW power, and 10kW heat. That means liquid cooling with pumps. radiators, and a much bigger motor to accommodate water cooling. Find an electric motor that had higher energy density than a gas engine for continous output, and I will stand corrected, and learn something new.
Here is a 220kg gas engine rated for 200kW continuous and 330kW peak: http://en.wikipedia.org/wiki/Porsche_993#Turbo_S [wikipedia.org]
Re:Hopefully not vaporware. (Score:3, Interesting)
Lithium-air is, IMHO, one of the least promising upcoming battery techs. It's really more like a fuel cell, and to be blunt, fuel cells suck. By that, I mean:
* Expensive per watt
* Short lifespans
* Inefficient
There are many, many promising next-gen battery techs other than li-air. Here's just a couple of my favorites.
You seem very knowledgeable. Which is to say, you've easily surpassed my ignorant bullshit detector on the subject matter. ;) Perhaps you'd care to speculate, wildly even, as to why big names such as IBM and the DOE would will be willing to heavily invest so many cycles into Lithium-air if the base technology sucks so badly. Does the fact that they're willing to invest in this technology hint they have some significant reasons to believe this technology trumps existing efforts? Or is it possible the applicable patent portfolio is more open with this given technology and its strictly a business/patent decision. If its the later, it still strikes me as odd because who cares if they can patent a crap-technology if they can't build a business model around it?
At any rate, please speculate away...
Also, are you a chemist? Do you work in the energy storage field?
Re:Hopefully not vaporware. (Score:3, Interesting)
It's the same reason why companies invested in fuel cells -- a long-term hail mary pass. Certainly li-air beats all of the techs mentioned (with the possible exception of digital quantum batteries) in terms of energy density. But it has huge challenges that may or may not be able to be met. Probably not. And yes, there is (or at least was) little patent coverage in that arena.
Also note that batteries aren't only about electric cars. This is IBM we're talking about here. Think laptops and cell phones: they're low power, efficiency and lifespan aren't as important, but energy density is. So there's a much more immediate application.
Re:Recharge time and price bigger issue (Score:3, Interesting)
There are two problems with what you wrote.
1) You compared the *fuel* used in gasoline cars to *electricity* generated, not to the *fuel* used to generate that electricity. So generation losses were already factored into the equation, but gasoline losses were not.
2) Power plants are more efficient than cars. Even coal plants in the US average 32% efficient (higher in Europe). NG baseload plants average about 42%. And transmission losses are tiny (92.8% average efficiency).