Slashdot Mirror
Nanostructured Li-ion Batteries for Electric Cars
schliz writes "Researchers at the Delft University of Technology are developing nanostructured batteries that are expected to deliver more usage between charges, and shorter charge/discharge times, to mobile consumers within the next five years. The batteries will improve electric and hybrid vehicles, researchers say."
Battery technology will experience a sort of Moore's Law with the demand for hybrid and all-electric vehicles. This is just one of the first stories.
I'm always a bit skeptical of such items till I understand how likely it is to cause a fire in my garage while I'm sleeping or when accelerating away from a stop light. New tech is great, but means not a lot till tested in the real world.
With battery technology, the higher the density, the higher the chances of uncontrolled energy release. When it's safe and fairly cheap, then I'll be really interested.
Support NYCountryLawyer RIAA vs People
Will this patent monopoly on the new tech be used to kill it, just like NiMH batteries were prevented from powering cars by the car and oil corporations?
--
make install -not war
batteries that are expected to deliver more usage between charges, and shorter charge/discharge times
I believe Sony has perfected the battery with the absolute fastest discharge time. I don't see how this can compete.
The theory of relativity doesn't work right in Arkansas.
It could mean that, but that isn't what is meant here. It can also mean that the battery can take in higher current during charge cycles and so reach the same state of charge sooner, and that the battery can release more current without failing or overheating due to its internal resistance, therefore making more energy available to the motors on demand - though yes, this latter capability does mean that the battery will be discharged sooner, given the same capacity battery, it is still better - because it can do what the old battery did (release at the old rate of charge) if that is what you want - but it can also give you more of a power surge for passing, towing, accelerating, getting out of (or into) trouble, etc.
Also, because a higher safe rate of discharge usually implies a lower internal resistance, it means that the battery wastes less energy when delivering current to a client device - the more internal resistance a battery has, the more heat is generated as a direct power loss, so most higher-current capable batteries tend to be a little better in this regard.
I've fallen off your lawn, and I can't get up.
Lead Acid batteries?
They have good energy density and can deliver considerable voltage for their size, and we've been using them for a very long time. It seems to me that perhaps someone should try researching different formulas for the acid and the chemistry of the plates.
Sure, they're heavy and there's always the danger of a rupture but they are good at doing what batteries are supposed to do, storing and releasing electricity.
LK
"Hi. This is my friend, Jack Shit, and you don't know him." - Lord Kano
Lead Acid Batteries must always be stored in a charged state. If the battery is left in a discharged state, a condition known as Sulfation occurs which makes charging the battery again difficult.
"Never try to tell everything you know. It may take too short a time."
Effectively it is about a 35AH battery with a total energy delivery of 12V * 35AH = 420WH. The equivalent LiIon batteries would weigh, I guess, around 4kg with packaging. As a result, lead acid batteries are unsuited to any automotive use except those where they can substitute for ballast, such as boats and powered wheelchairs where the batteries help lower the centre of gravity.
Quite a lot of research has gone into the lead/peroxide cycle, especially given the constant desire to make them smaller and more reliable. It hasn't been hugely successful. You can have high discharge rates and long life at the expense of much more weight and much higher cost, but the nature of the cycle itself (the production and destruction of large amounts of lead peroxide) makes it hard to design a system that can handle many charge/discharge cycles without very large and heavy storage arrays.
Pining for the fjords
It's a not too well known fact that, in the beginning, a lot of things *were* actually powered by electricity, *before* something else took it over. That something else wasn't necessarily better then the batteries they'd replace, but, sadly, history is full of examples where a less good alternative wins over the market (betamax vs VHS, anyone?). Somtimes electricity did win (it replaced gas for lightening homes/streets) but sometimes, alas, it didn't.
The same was true for cars. Many would think cars were always powered by diesel/petrol, but nothing is further from the truth. In fact, there were many fuels used to drive cars when they were first developped, and electricity-driven cars were actually a rather considerable percentage of cars. But then petrol came and took it over for reasons that are unclear (it has been speculated that it might had something to do with the sound, strangely enough; it made for a more impressing 'look at me, here I am!' - not unimportant to the late-victorian elite of that time. Heck, even today half of the gadgets are bought to show off (blu-ray, HD-DVD, anyone?). In that time, battery- or oildriven cars were in fact ahead of the petrol ones, but that rapidly changed the more popular the petrol-using cars became. In a few decades, the rest was all but gone.
If that hadn't happend, it is obvious we would be FAR ahead of our current state of developement where batteries and electricity-storage is concerned (just like petrol-injection has come a long way since the 19thy century). Just imagine the state of technology now on the same scale as petrol has improved, and all what we invent now (including the nano-tubes) would probably have been developed ages ago. It would have led to efficiencies and yields we can only dream of today. And also imagine the impact it would have had on other areas; a lot less - or none at all - CO2 from cars (and maybe the petrol-industry as a whole would not have reached the peak it has today) and all the problems associated with that would not exist (maybe even les wars)! (Arguably, one would - maybe - have had a environmental problems with acids and such, from the batteries; in that respect, vegetable oil would have been best, perhaps.)
It's funny (well...) to think how one little thing in our history can lead to such huge (and possibly devastating) consequences for humanity more then a century later.
--- "To pee or not to pee, that is the question." ---
Let's assume an average cruising consumption of about 15kw for a small car. At 60mph with a 300 mile range, that's 75kwh. To charge those cells in 5 minutes, assuming an 80% efficiency, will need 75 * 12 * 1.25 =~ 1.1 Megawatts. At 440V, even with a 3-phase charger, that's over 1000 amps. At 11KV it's a more reasonable 100A, but the weight of the inverter gear and the shielded connector in the car is considerable and you are going to spend rather more than 5 minutes padlocking the interlocks and cross checking before and after charge. At 440V the main issue will be the weight of the cables. Three cores of around 400mm cross section each are rather heavy.
It's possible to imagine a world in which fuel stations supply exchange cells, but given the natural nervousness of most drivers when close to empty, it's unlikely to be practical or cost effective.
The model is wrong. You have to imagine a world in which car parks have charging stations that charge at reasonable rates, as do hotels and houses. You will need a general beefing up of the electricity distribution network, and you will need plenty of nuclear, solar and wind energy sources. And people will have to plan maybe a little further ahead than they do at present. Long trips will mandate an overnight stop. Probably a good thing as the only accidents I have ever had were after driving too long in a day.
On that model with a more reasonable 10-hour charge, the necessary charging rate is about 9KW - still a heavy cable, but with a socket about the size and complexity of the sort used for portable machines in factories and for boat shorepower.
Just don't try to use your wind turbine. In our location, to run my small car on its current, fairly low usage cycle, I would need a 6M diameter turbine on a 40M pylon, and I suspect the neighbours would object.
Pining for the fjords
I have to disagree with your leading statement. The energy density of lithium-ion batteries today is adequate for making practical electric cars. Of course more is always better, and I'm optimistic that it can be improved further -- but energy density is no longer the big sticking point that it was.
The little two-seat Tesla Roadster with a 250-mile range has been demonstrated, and multiple companies are now working on more practical four-door cars which can have a 200-mile driving range. This doesn't require any breakthroughs, and it will get you "to the next town" with very few exceptions.
The critical areas that need improvement are cost and service life. Tesla Motors are projecting a life span of five years or 100,000 miles for their carefully managed battery pack. That's much better than the two years you stated. I think with the research that is ongoing, service life will further improve over the next several years. (And GM are betting on this happening to make their Chevy Volt concept workable.)
I think the requirement that cars be "refueled quickly" is overstated. The longer the range becomes, the less you need to refuel or recharge it quickly. With a dependable 200-mile driving range between charges, and the ability to recharge overnight at home, most people won't need to stop at a charging station mid-trip all that often. If you can get the range up to about 500 miles, then rapid charging would become moot for the great majority of people. (At least speaking for myself, I don't think I've ever driven more than 300 miles in a day's time, and I wouldn't want to drive more than 500 in a day if I could possibly avoid it.)
I have looked into flywheel storage technology. It looked promising several years ago, but battery technology advanced faster and has left flywheels behind. Notable problems you have with flywheels are: energy density, energy losses while the flywheel is spinning idle, and safety concerns about its failure modes.