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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."
it means that you can pull the energy out of the battery faster - "expected to deliver more usage between charges" would seem to indicate that actually the capacity is significantly increased.
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
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
No more maintenance that any other battery. If you want to get some feedback from people that are already using these, check out this electric vehicle forum. http://endless-sphere.com/forums/ I think they are already ahead of what most think is possible with electric vehicle transportation.
Actually, they're getting very close, and right now, there are projects projecting power densities three orders of magnitude higher than batteries, in the 100 KW/kg range. So I don't think the current state of affairs (batteries > ultracaps) is going to obtain for very much longer.
What? ultracaps have the same discharge curve as any capacitor does; the voltage drops very smoothly as the energy in the cap is dispensed. "Dealing with it" is nothing tricky at all, the technology has been in place for this for literally decades. Modern switching power supplies are *very* efficient at creating constant voltage outputs from all manner of raggedy inputs across a wide range of input voltages, if and when required. They can be engineered to be reliable and very long lasting. This is simply a non-problem. Also, ultracaps can absorb energy (for example, from regenerative braking) at a much higher rate, leading to less wasted energy. We have all manner of high-current switching devices with such low on-resistances these days as to be utterly amazing to an old-timer like me.
You're just hand-waving here. Recycling is one issue, toxicity is another, corrosion is another, and all of them are far less critical for ultracaps - not to mention that the lifetime of an ultracap is so much longer (up to a quarter of a milling charge/discharge cycles, or more) than that of a battery, so it is that much more seldom that recycling becomes an issue. It really isn't reasonable to say that ultracaps pose the same kind of environmental issues that batteries do. They don't. Perfect? No. But what is?
Yes, but (a) ultracaps aren't batteries at all, and (b) ultracaps are increasing in capacity at a prodigious rate, where batteries are not. Mind you, they're coming from behind, but they're a brand new technology with tons of new research driving the improvements, while batteries are not new and many, many avenues have been tried and abandoned for increasing battery capacity for exactly the reason you cite: It is hard to improve the current battery designs.
I've fallen off your lawn, and I can't get up.
...[electricity] produced by environmentally friendly means (IE not oil, not dams which destroy vast eco systems, not wind farms which kill birds) ...nor, say, solar cells, because most are sealed and won't allow poor spiders to nest in them?!?Watch out, your computer screen is surrounded by something called reality. Common-sense may come in handy should you chose to visit it sometime.
Nanoscale Lithium battery technology leads me to think A123 cells. The cell from this startup are already on the market, powering handheld screwdrivers and model airplanes. They use a patented LiFePo4 reaction(or was there some sulfur in it too, dunno) and their process is much more ideal for automotive transport than NiMH(not enough energy density) or LiPo(Lithium polymer, it's what's making laptops go up in flames the last few years). LiPo has the highest energy density, but is very unsafe when punctured in a crash(or when overcharged): all energy in them will release in a short time, possibly causing fire as the decomposing polymer inside escapes as a flammable gas. The other drawback is that they have a very short lifespan: Max 500 charge-cycles (better count on 100-200) or 3 years (cells degenerate even when not in use). Thus far LiPo cells are prohibitively expensive, and no hybrid owner would like to fork over a few K every year for new batteries.
the A123 process is much more resilient wrt to abuse: you can run them down completely unlike LiPo or lead-acid, the stand overcharging much better, and if punctured they don't go up in flames. The company rates their cells as being able to deliver 2000 cycles, which is much more than lipo, NiMH, NiCad or Lead-acid.
And as far as I know, they have no ties to Delft University, but I have not read TFA yet...
They are here.
This space is intentionally staring blankly at you
Toshiba announced research on a technology for fast charging li-ions over two years ago. This was using nanotech materials for an improved anode (maybe cathode too), enabling fast charging (80% charge in one minute) and long life (99% capacity after 1,000 charges). A similar approach was also annouced, about the same time, by Altair Technologys in Reno. It's all about increasing the effective surface area of the anode, and perhaps making it from stronger stuff.
In traditional Li-ion cells, a big wear factor is that the anode can form a parasitic battery with the electrical contact, causing the terminal to eventually wear out, faster as you approach full cycling the battery. Heat is also a factor, in both terminals and the full cell... the higher internal resistance of the Li-ion vs. NiMH (or better still, NiCAD) limits peak power, and also increases the risk of damage or, particularly in quesitonably made cells, explosions.
Dramatic improvements in both of these are necessary to enable practical (in a commerical sense) pure electric vehicles (BEV). There's no conspiracy necessary... traditional NiMH cells are a problem for full electrics.. which the actual reason none of these cars have been successful. Not to mention the expense... the Toyota EV-RAV4, for example, cost $42,000 and gave you about 100 miles on a charge.. and that with Toyota still selling them at a loss (as they did in the early days of the Prius, too).
In a hybrid, the batteries are only partially cycled (my 2003 Prius runs the NiMH cells over 40% of their capacity range; Toyota extended this to about 60% on the models starting in 2004), and that keeps them very long lived. Natrually, better batteries make a better hybrid, but the fact my Toyota can only go about 2-3 miles on a full charge doesn't impact its general use; the issues around battery technology today make the BEV a small niche product.
But the energy density is just too low even full cycling NiMH to make a BEV with mass appeal... most people would demand at least 200-300 miles of range, charging times on-the-road similar to that of petrol fueling (not the minimum of 15-30 minutes you'll have with today's cells), and long life (full cycling NiMH, they're good for about 500-1000 charges).
Once you have a higher density cell that doesn't wear out and can be charged in under 5 minutes, full EVs will be practical enough for a mainstream automaker to POSSIBLY launch a full production car, not just an experiment. This is critical technology for improving hybrids as well, and keep in mind that all practical FCEVs will also be hybrids (fuel cells suck at peak power demands, they like to be slow and steady, so you need a battery or supercapacitor to enable the peaks).
-Dave Haynie
Quick and dirty rebuttal. . . .
1. fast recharge isn't needed if driving range becomes long enough (say 300 to 500 miles)
2. electric cars pollute much less than gasoline cars, due to their energy efficiency
3. tens of millions of electrics can be charged using off-peak power without building any new power plants
4. http://www.youtube.com/watch?v=u5kkU23bfEc
It's not maintenence; it's lifespan. Conventional Li-ion (as powers most laptops) are high energy density, high flammability, moderately high cost, and short lifespan. Li-ion battery lifespans are particularly frustrating because they're not very tied to charge-discharge cycles; they're much more correlated with age and temperature. As I mentioned, there are a number of Li-ion variants, some of which are already on the market. However, most of them sacrifice energy density to reduce flammability and/or lifespan.
Then the winter came, and the Grasshopper died. And the Octopus ate all his acorns. Also, he got a racecar.