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Discussion Starter #1
OK, before you all groan about me bringing this old chestnut up again, it's not me suggesting this (for a change! :wink: ). Toyota are giving it a shot in aid of their potential upcoming performance Prius. Fingers crossed it gets the green light!

http://www.autoexpress.co.uk/?news/ae_news_story.php?id=51666
 

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I do not believe it is Toyota's job.

Regarding to "Japanese-market Yaris Turbo", the Japanese version Yaris is called Vitz and there is no such Turbo model from Toyota.

Maybe, the article one is a Modellista version Turbo for after-market.

I also doubt to use the Li-Ion battery.
The charging/dis-charging profile is completely different from the NiMH battery.
We have to replace/reprogram the Battery and Hybrid ECU's.
It is not practical jobs.

Regards,
[email protected]
 

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Well it is written in Europe where it is called the Yaris. Maybe the writer didn't do enough research into the name haha. Perhaps the turbo Vitz may be a 3rd party doing?
 

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ElectricTroy said:
Don't Lithium batteries cost ~$50,000???
More like 25% more than a NiMH per KW. The main problem with Li ions is their safety factor - they have a slight tendency to catch fire, particularly the high discharge rate ones. They do better in cold weather than any other battery tech, but..... I wouldn't want to own a car with them that is being used in Texas, Florida, Southern Cal. or Arizona. Another problem is, other than primary battery usage, Li ions don't have a history of being used in large projects like NASA, Military, etc., primarily because of their incindiary potential. And for this reason, the large 50KW+ batteries really haven't made it past research manufacturing levels. So there's no high volume manufacturing history which can give someone enough experience to using them on large projects, like cars. Don't get me wrong - we'd be able to carry around twice as much battery power in the same weight so I'm all for Li ion. Just not at the expense of providing a thermal barrier in the back of passenger seats. :lol:

Maybe Toyota will offer a special "northern" version of the Prius for Canada, upstate NY, Wisconsin, upstate Minnesota, New Hampshire, Vermont, Maine that includes these batteries. Until they can guarantee that a high discharge rate Li ion won't put on an inpromptu fireworks display, you won't be seeing them soon in Toyotas.
 

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Some problems with current lithium-ion and li-polymer batteries are:

-Safety. If you short them, they can catch fire and burn, During some testing we did, the results were pretty dramatic - we got big jets of flame from the venting electrolyte. In an accident, where you could crush cells near the fuel tank, you could see some problems.

-Charge regime. Ni-MH can accept current until they are full; li-ions need a voltage limited taper charge at the end to prevent cell damage. This means you can only get about 60% of their charge back into them via high rate charging (like regen braking.) This isn't as much of a problem for pure electrics.

-Max current. Li-ions have considerably higher specific energy (wh/kg) than ni-mh, but ni-mh can output a more current per kg. Thus a li-ion pack will give less performance (but more range) than a same-weight ni-mh pack.

-Cost. They're currently about 2x the cost of ni-mh per wh.

Some of these may be overcome in future designs, of course. Li-ion is currently the best-density mature battery technology out there,
 

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billvon said:
Some problems with current lithium-ion and li-polymer batteries are:

-Safety. If you short them, they can catch fire and burn, During some testing we did, the results were pretty dramatic - we got big jets of flame from the venting electrolyte. In an accident, where you could crush cells near the fuel tank, you could see some problems.
They had similar problems with the NiMH in the Prius during the initial design stages...an advanced cooling system and design to prevent such fires in a collision can't be that difficult.

-Charge regime. Ni-MH can accept current until they are full; li-ions need a voltage limited taper charge at the end to prevent cell damage. This means you can only get about 60% of their charge back into them via high rate charging (like regen braking.) This isn't as much of a problem for pure electrics.
That's almost exactly what the charge regime is in the Prius Currently...

-Max current. Li-ions have considerably higher specific energy (wh/kg) than ni-mh, but ni-mh can output a more current per kg. Thus a li-ion pack will give less performance (but more range) than a same-weight ni-mh pack.
Can't speak to that, but wonder if combining Super Capacitors...or even standard capacitors...would help with the rapid charge/discharge issue someone mentioned before as well as being able to deliver more instant current. I'd think the inverter could be improved to adapt to that as well. I do know that LiIon was given serious consideration back in '95 during the original design. There's also an interesting paper about the battery choice put out by Toyota that I have at home, but I'm at work at the moment. If I remember I'll post it here.

-Cost. They're currently about 2x the cost of ni-mh per wh.
I didn't think they were that much more, but can't swear to it.

Some of these may be overcome in future designs, of course. Li-ion is currently the best-density mature battery technology out there,
 

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Here's the article:

Note the 4% improvement in fuel economy with the Li ion over NiMH. Clearly cost is mentioned as a factor. I found the last 2 paragraphs interesting, esp. the capacitor and supercap info.
 

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Thanks for that article. Very informative. Am I to understand that my Prius' brakes already use supercap technology?
 

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No stock Prius has supercaps. Supercap manufacturers are interested in getting their products adopted by the hybrid market, so some experiments are probably ongoing or planned. I recall hearing that Honda did some experiments, possibly associated with their fuel cell tests.
 

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efusco said:
They had similar problems with the NiMH in the Prius during the initial design stages...an advanced cooling system and design to prevent such fires in a collision can't be that difficult.
The problem we found is that if you puncture the case of a battery with a metal object (like a nail) you get:

1. Heat from shorting the plates together
2. Release of flammable electrolyte
3. Sparks from the intermittent short

At least 50% of the time we got ignition. (This was with the 18650 graphite li-ion cell, the most common cell used today.) Since the electrolyte in ni-mh isn't flammable there isn't as much of a problem. But perhaps with changes in electrolyte the problem could be minimized.

efusco said:
Can't speak to that, but wonder if combining Super Capacitors...or even standard capacitors...would help with the rapid charge/discharge issue someone mentioned before as well as being able to deliver more instant current.
I think that's the next stage. Maxwell Labs has some D-cell-sized 350 farad caps now; they may drop in price enough to make hybrid cap banks doable. But if we ever get to that point, expect the caps to replace batteries completely. They don't wear out as quickly, they deliver orders of magnitude more instantaneous power, and they have no charge/discharge issues. The only problem right now is energy density, but that's less of an issue in a hybrid.

A supercap-based hybrid would be an interesting animal. It would go like hell off the line, but have to use its gas engine more often due to lower energy storage capacity. I think that one thing that's a problem with hybrids now is the sense (in the public eye) that they are for underpowered cars; they're typically paired with a low-output gas engine and are optimized for gas mileage rather than power. A well designed supercap hybrid wouldn't have much trouble beating most gas-only cars in 0-60 times. Once hybrids become known as "the performance option" their popularity will increase 10x. (Not that we really need to increase demand.)
 

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Discussion Starter #13
Yup, safety has for ages been the major stumbling block with using LiIon in large battery applications. But, the whole flammability issue appears to have been solved recently by Japanese company Bridgestone. They have developed an electrolyte additive that renders the batteries non-flammable. You can read about it here and here, but this is an excerpt from the links:


" Tokyo (November 20, 2002)--Bridgestone Corporation has developed technology that overcomes a stubborn drawback of lithium batteries. The company this month unveiled an additive for the batteries' electrolytic fluid that renders the fluid nonflammable. Bridgestone's additive is the first in the world to eliminate the fire danger in lithium batteries without affecting battery performance adversely.

The chief drawback of lithium batteries is the flammability of the organic solvent employed in their electrolytic fluid. That flammability is not a significant problem in small batteries. But it becomes a serious issue in large batteries. That has limited the usefulness of lithium batteries in such potential applications as electric vehicles.

The company is preparing to test-market the additive in 2003, and it projects that annual sales of Phoslyte will reach ¥1 billion in 2005 and that half of the battery makers in Japan would begin using the additive. That would boost the lithium-ion battery market from around 300 billion yen ($2.5 billion) in 2000 to 1.6 trillion yen ($13.1 billion) by 2010. "

Also, I reckon that if Hitachi and its related companies have invested so much in a factory for LiIon destined for hybrid cars, then they must have solved the issues that were holding LiIon back from hybrid cars.

Edited to say, PS thanks for the great link Efusco!
 

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Odd how almost all of Asia is concentrated on Li-ion batteries.  They can produce them at their manufacturing plants with more efficiency than elsewhere even if they are difficult to manufacture.  Lots of plans for nanotechnology techniques to be used for making better efficiencies.  There's another battery technology the Europeans (Saft) and Americans (Lawrence Berkeley National Lab - patent 5,441,820 & Electric Fuel Corp.) are persuing: zinc-air.  They tested a 40ft ev only city bus in Rome, NY during August with full time air conditioning and got 130 - 145mi average.  Buses normally only go 90 miles a day in NYC.  They also used ultracapacitors but the batteries they used where hydraulically recharged.  Saft (a Swiss company) is pushing their 400 Wh/kg design to European car companies and I wouldn't be a bit surprised to see a European hybrid with this technology.  I believe they fixed their problem with the bifunctional air electrode so it can get 1,000 cycles.  With air as part of the electrolyte they are remarkably easy to manufacture.
 

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drash said:
There's another battery technology the Europeans (Saft) and Americans (Lawrence Berkeley National Lab - patent 5,441,820 & Electric Fuel Corp.) are persuing: zinc-air.
Zinc-air is a cool technology, but the current large-cell designs I've seen are not yet rechargeable. You have to replace the battery. Some modern designs have easily replaceable plates; swap the plates out and you're ready to go again. Other designs allow you to suck out a zinc slurry and refill it with new slurry to "recharge" it; the slurry is then returned to a reprocessing plant where it's turned back into 'charged' slurry.
 

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Discussion Starter #16
billvon said:
Zinc-air is a cool technology.
Yup, Zinc-air is cool but lithium-air is just awesome! Check out what Polyplus had to say about their new lithium aircell at a recent progress in LiIon conference:

" Lithium Aircell has a theoretical specific energy of 11,600 Wh/kg. The high specific energy of the Li/air couple is close to that of liquid hydrocarbons such as gasoline (!!) "

I'm guessing 11,600 Wh/kg theoretical should lead to ~3,000 Wh/kg practical, so a 25kg pack slotted in by the "gas" station attendant to replace your depleted pack would give you an all-EV range of almost 400 miles! Beat that fuel cells! 8)
 

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One issue not yet mentioned is that of disposal of old cells. Cells containing lithium are not so easy to deal with as say, NiMH.

In Europe, automotive manufacturers may be forced to take back vehicles at the end of their useful life or be made to contribute to the costs of recycling.

Here in Germany, it is against the law to simply discard any kind of battery in regular waste. All batteries must be processed to remove or recycle harmful components - this responsibility rests with companies selling batteries or products containing batteries.

This may have some influence on a manufacturer's choice of technology.
 

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Other problem with newer Lithium types, other than the one Fuji Heavy is working on, is that their discharge rate is a little low. A 5C rate is way too low for electric/hybrid vehicle use.
 

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Discussion Starter #19
jg said:
One issue not yet mentioned is that of disposal of old cells. Cells containing lithium are not so easy to deal with as say, NiMH.
It's not the lithium that's the problem - it's the other components of some lithium chemistries. For example, Saphion's LiIon cells which use quite an unusual chemistry (phosphate) are already landfill approved (see here). But I guess in practice the lithium itself is quite valuable so old batteries would end up being recycled.

As for the rate issues, recent LiIon has now leapfrogged NiMH. Some of the best rate NiMH cells are the ones in the Prius, rated at 1,300W/kg max (limited to ~700W/kg in practice). But Lithium polymer is already up at 3kW per kg (LG-chem cells) and others even higher, as much as 4kW per kg. These designs have been developed for use in hybrid applications, but the lower rate designs should still be fine for EV use with a big battery pack.
 
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