New Battery Tech: 4 times Wh/kg of lithium ion batteries

[Skipjack]

Next Big Future once again has an interesting bit here:

http://nextbigfuture.com/2010/02/new-li ... -have.html

50% better than lithium ion batteries is not bad aready, the theoretical 400% sounds really good though. That would actually make batteries a lot more reasonable. How much of that will result in a real usable product and how much of it is marketing (fishing for funding) bull is of course another question all together.
Still, at 400% the energy density of lithium ion batteries, we are actually talking reasonable performance for a lot of applications. Even electric cars become more reasonable that way (current lithium ion tech is not good enough, at least IMHO) .
Of course the last question that remains is the price. How expensive will these batteries be compared to lithium ion.

[93143]

This could rock. Isn't that better than EESTOR?

Does anyone know what kind of power-to-weight ratio you can get from a compact, high-voltage electric motor in the 250-1500 hp range? Could you get near 10 kW/kg? Or would that require superconductors?

[Munchausen]

This is very early work. In fact so early that a publication is hardly meaningful. A little proof of concept cell that have been cycled 20 cycles. Forget about it for the time being.

[dnavas]

This is very early work. In fact so early that a publication is hardly meaningful. A little proof of concept cell that have been cycled 20 cycles. Forget about it for the time being.

LiS has been around/researched for awhile. This kind of energy density is pretty good, actually, given other LiS I've read about. However, it is wise to ask questions about cycle and calendar lifetimes. LiS has a tendency to cycle poorly. Possibly the Si nanostructures will help?

[Munchausen]

LiS has been around/researched for awhile.

Various types have been tried since the beginning of the eighties. However, theese electrode materials are brand new. From last year.

This kind of energy density is pretty good, actually, given other LiS I've read about. However, it is wise to ask questions about cycle and calendar lifetimes. LiS has a tendency to cycle poorly. Possibly the Si nanostructures will help?

I will make my way through the article in the coming days. My first impression is that this is a tiny little proof of concept. Way to early to make any predicitions at all on cycle and calendar lifetimes. Or any other predictions at all on at practical battery, really.

[dnavas]

I will make my way through the article in the coming days. My first impression is that this is a tiny little proof of concept. Way to early to make any predicitions at all on cycle and calendar lifetimes. Or any other predictions at all on at practical battery, really.

What I saw wrt cycles did not appear to be terribly promising, but I just skimmed.
Maybe the Si helps, but the manufacturability has to be ... entertaining.

[DeltaV]

Does anyone know what kind of power-to-weight ratio you can get from a compact, high-voltage electric motor in the 250-1500 hp range?

Define "high-voltage"...

[ladajo]

I do not think I would associate the words "compact" and "electric motor" when speaking of 250-1500HP. In the conventional market you are talking about serious motors with serious metal, be they AC or DC. Now if you are talking superconducting motors, that is another topic.

If you want to narrow down the HP and voltage ranges you are looking for, I can spot you some frame sizes, from which in turn you can postulate physical weights.

Edit: corrected bad typing...

[Aero]

Back when Gas was $4.00 a gallon I looked around at industrial motors. Not what you need, but 150 HP Toyota weighed over a ton.
I also found an article about a German company who converts Porsches to fully electric. Their in-house motor was 8 inches long and 13 inches in diameter but I don't remember the power. Just guessing, I think it was somewhere between 250 and 500 HP. Copper wound wire is 8.92 metric tons per cubic meter. (Copper wire density) The rest of it is probably about the same density with very little cooling air channels. That gives a volume of about 0.07 cubic meters and 0.62 metric tons for copper and iron. Its up to others to estimate the density of lighter materials (aluminum?) because 0.62 times 2200 lb/m ton gives 1366 pounds, pretty massive for a high performance Porsche.

[ladajo]

... 150 HP Toyota weighed over a ton...
... in-house motor was 8 inches long and 13 inches in diameter... somewhere between 250 and 500 HP....

8inches long and 13inches in diameter seems purdy darn small for something pushing 250-500HP. Granted just a guess. Your numbers don't match up. 150HP over a ton (2000lbs), and 250-500 at 1366lbs?

In any event, the rotor is not going to be solid copper, it will have a steel shaft, and an aluminium and iron core. The stator will be copper on iron core. then house all this in an almunium frame, slap on steel bearing s and endbells, it makes for one large heavy piece of metal. For a DC version, add some steel shaft length for the commutator, plus the commutator itself, essentially another block of copper. Probably the Porsche kit was a DC motor, cause back in those days, High Torque meant DC. Nowadays, you can kick torque butt with a decent quality Inverter pushing a much lighter weight equivilent HP AC motor. I spent some time in the early 90's doing just this type of application design and build. I would retro old industrial DC driven machines with Inverters and High-E AC motors. A typical setup would be about half the total weight, 1/3 the total space, and significanlty more power efficient supplying the same torque and HP needs, with much better digital precision speed control able to reach much higher shaft speeds at the touch of a button. Add some dynamic braking heating up a big resistor (batteries nowadays...) and you had quite the setup. (Inflating my own balloon here)...I actually was able to crack one of the long standing (100 years) production throughput limiters for textiles using this same concept on a "Fulling Mill". Brits couldn't do it, Canadian's couldn't, Scot's couldn't, but a ex-pat Kiwi did! Not only did I crack it, I doubled the standing limit. Still makes me smile to think about watching one of those mills slam to a stop in less than a yard of cloth running at full tilt. The fly weight was tremendous. I did this in 93ish. Of course there were some cool IGBT pack explosions in the science project stages, but the end result was a 100HP transistor switch dynamic braking setup, on a 100HP Invertor driving a 75HP AC motor. The original DC was 40HP using a magnetic clutch and brake assy (about 40% eff), but I had to over size almost double to get service life accounting for the braking transients. The retro paid for itself in less than 3 months of machine operations. After that it was all gravy for the company. Today we have hybrid cars using the exact same technology. I used Hitachi Inverters then, and Hitachi was VERY interested then in how I applied them for the dynamic brake setup.

[MSimon]

1 cu in = 1.6387064e-5 cu m.

8" long X 13" dia = aprox 1062 cu in.

= 0.0174 cu m

aprox weight = .0174 * 9 tons / cu m = .157 metric tons

or about 350 lbs - give or take.

[Aero]

1 cu in = 1.6387064e-5 cu m.

8" long X 13" dia = aprox 1062 cu in.

= 0.0174 cu m

aprox weight = .0174 * 9 tons / cu m = .157 metric tons

or about 350 lbs - give or take.

That's funny. I calculate a cylindrical volume, length * pi * d ^2 and get the wrong answer. Using r works better and 350 lbs works better, too.

Note: The information in the article was current back in fall of 2008. That's also the time I checked out Toyota industrial motor catalog. I think there is a lot of room for improvement in motor power/weight and expect to see some soon.

[ladajo]

8 X 13 roughly equates to a 184 Frame motor. Typically 184 does not get more than 5HP in a 3phase AC. Its heavy, but you can pick it up.

To put it in perspective, a 150HP AC 3phase would be about a 445 Frame.
That would make it about 22 inches in diameter, and approx 32 inches long. (not counting the shaft and mounts, be it feet or c-Face.) You are not going to pick this up.

[ladajo]

Found this on Amazon...(you can buy ANYTHING!)

http://www.amazon.com/150hp-1790RPM-Leeson-Electric-
G151371/dp/B000AAVYW8

This Leeson ships at 1900lbs.
Equivilent DCmotor is gonna be about a third heavier if I had to guess.

Can you give a link to the car mod article?

[DeltaV]

As of 5 years ago... http://gltrs.grc.nasa.gov/reports/2005/ ... 213800.pdf (~7 MB)

Tested room-temperature motor: 2.14 hp/lb

The axial-gap permanent-magnet motor built for TACOM, shown in figure 7(c) at 1500 hp and 700 lb, though about 3.5 times as heavy as the turbine engine for the same power, is the best room-temperature motor, in terms of power density, for which we have data above 100 hp.

Tested cryogenic motor (not superconducting): 6.09 hp/lb

Cryogenic motors, as indicated above, have the greatest specific power capability. Only one cryogenic electric machine known to us, the Air Force generator, was designed with a flight-weight objective. This is the 220 lb Air Force synchronous machine pictured in figure 6. At its potential power capability of 1 MW (ref. 6), this machine would have the highest power density of any actually built electrical machine known to us. (It is shown in figure 7(c) at 220 lb and the machine’s indicated power potential of 1 MW (1340 hp)). Note its power density is almost equal to that of an equivalent turbine engine.

Preliminary-design cryogenic motor (not superconducting): 19.23 hp/lb

One point is shown (at 50,000 hp, 2600 lb) for a preliminary design of an LH2-cooled synchronous machine (ref. 15). This cryogenic machine approaches being light enough to power a transport-sized aircraft, being about half the weight of an equivalent turbofan engine. This leaves some room for the weight of other components (electric power source and power conditioning), if they are acceptably light.

Superconducting motors: ___ hp/lb?

The above are low-voltage motors.

High-voltage electrostatic motors (e.g. Jefimenko's stacked-disc corona motors): 1000hp/m^3?
Unexplored regime...
Lower mass density but higher volume. No heavy magnetic parts. Composite structure possible.
Arcing/breakdown a key concern (vacuum, SF6 gas, ...?). 10s of KV or higher?