Thermal Nitridation Enhances Performance of LTO in Li-Ion Batteries
21 October 2008
The reversible capacities of (A, green) pristine and (B, red) nitridated Li4Ti5O12 with different charge/discharge current densities during cycling. Click to enlarge. Credit: ACS |
Researchers at Korea’s Samsung Advanced Institute of Technology (SAIT) and Sungkyunkwan University report that the thermal nitridation of lithium titanate (Li4Ti5O12, LTO) to modify the oxide structure of the material to introduce a thin conductive film can result in an increase in capacity of up to 6 times (around 120 mAh g-1) at a high charge/discharge current density (10C) compared to pristine LTO material.
At low current densities below the 1C-rate, the capacities after the nitridation do not differ much from those for pristine Li4Ti5O12—around 150 mAh g-1. A paper on their work was published online 15 October in the Journal of the American Chemical Society.
A number of battery makers, such as EnerDel, Toshiba, and AltairNano, are using lithium titanate as an anode material because of its improved thermal stability compared to conventional carbon anodes, and hence improved fast-charge and safety characteristics. The downside of LTO is a lower cell voltage (2.5V vs 3.7V, according to the DOE), and a low capacity density of about half that of graphite.
Thermal nitridation has been known to change the oxygen stoichiometry in some oxides and to introduce nitride thin films. Thus, modification of the surface structure of Li4Ti5O12 via annealing in NH3 should change Li insertion/extraction behaviors, and it should also make bonding between surface Ti and N simultaneous. To address this issue, we introduced thermal nitridation to Li4Ti5O12 and found, for the first time to our knowledge, that it can introduce a mixed-valent intermediate phase, Li4+δTi5O12, and a surface conductive layer, TiN, with a significant enhancement in the battery performances.
—Park et al. (2008)
The ammonia gas decomposes the surface LTO into a conductive layer of TiN and Li2CO3 without a change in the bulk lattice parameter; it may also modify the surface structure in a way to accommodate the single phase Li insertion and extraction, the researchers suggested.
Resources
Kyu-Sung Park, Anass Benayad, Dae-Joon Kang, and Seok-Gwang Doo (2008) Nitridation-Driven Conductive Li4Ti5O12 for Lithium Ion Batteries. ASAP J. Am. Chem. Soc., doi: 10.1021/ja806104n
If this is true - it will be better than any EEstor!!! Of course cost and reliability concern follows after.
Posted by: Darius | 21 October 2008 at 10:29 AM
I Trust Altair Nanotechnologies will be interested in this.
Posted by: BuckyBalls | 21 October 2008 at 10:52 AM
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Posted by: Zalary TypePad Support | 21 October 2008 at 01:07 PM
Darius
It won't be difficult to outperform EESTOR, since EESTOR is nothing but vaporware.
I bet a bottle of Champagne that EESTOR will postpone his next milestone (again) and won't have any cell tested by third party next year, but will keep announcing more deals and patnerships with fooled innocent companies like ZennMotor car
Posted by: treehugger | 21 October 2008 at 01:14 PM
Very promising.I think the keyword here is "Samsung"
Posted by: GreenPlease | 21 October 2008 at 02:24 PM
No . . . keyword is "paper." As in "we did a study." When the keyword is even "prototype" you can talk like it means anything.
Lower voltage means more cells, different electronics, different standards, reliability hit, bigger motors, different chargers, etc., etc.
There are no standards developed yet, or even any accepted standards bodies to turn to for all this EV stuff. It is about 1976 for the microprocessor/PC right now on this. In about 30 years it will advance from that to where semiconductors, SW, computer science, etc are today.
In the meantime oil, natural gas, and coal, with a little nuclear and maybe a few dams and some solar plants that run in the sunshine to get through those 30 years.
The electric car is not dead -- it just has not been completely invented yet . . . . .
Posted by: JV | 21 October 2008 at 02:55 PM
Material science is happening at a break-neck speed. If the electric car is not yet ready, there are always electric motor cycle or electric bike opportunities out there...
Posted by: Lulu | 21 October 2008 at 04:07 PM
In 1976 the microprocessor industry was 8 years old already. If indeed the two technologies are on a similar growth track - we should see a figurative explosion along the lines of Moore's Law soon. Not only in electrical storage materials - but also in areas like nanoparticle materials catalysts: http://www.greencarcongress.com/2008/10/real-time-obser.html
We can expect to see rapid simultaneous development of energy storage and energy production chemistry and materials. All of which will make even the microprocessor revolution look somewhat tame.
Posted by: sulleny | 21 October 2008 at 05:22 PM
In 1976 the microprocessor industry was 8 years old already. If indeed the two technologies are on a similar growth track - we should see a figurative explosion along the lines of Moore's Law soon. Not only in electrical storage materials - but also in areas like nanoparticle materials catalysts: http://www.greencarcongress.com/2008/10/real-time-obser.html
We can expect to see rapid simultaneous development of energy storage and energy production chemistry and materials. All of which will make even the microprocessor revolution look somewhat tame.
Posted by: sulleny | 21 October 2008 at 05:23 PM
Sulleny
I sincerely doubt that the technology of batteries will follow the Moore law, there is no evidence to support that, what is true for one type of industry is not necessarily true for another. Each industry has its own specificity. Progress in battery has always been slow, battery (at the difference of micoprocessor) is an old industry and if they could have made pogress faster they will have done it, believe me, because the markets opportunities for more powerful batteries have always existed. I don't believe in disruptive technology for batteries the progress will be incremental.
Posted by: Treehugger | 21 October 2008 at 05:47 PM
Nice post
Posted by: Car Rental Barbados | 22 October 2008 at 12:07 AM
@ Treehugger,
"I don't believe in disruptive technology for batteries the progress will be incremental."
Going from the 300 cycle life at 1C of late 90s lithium-ion batteries to >15,000 cycles of deep charge/discharge at 10C of today's titanate batteries must surely be considered disruptive!
Or how about the 500 Wh/kg lithium-sulphur batteries from Sion et al? (still with safety and cycle life issues, but with 5x the capacity of A123 cells etc that would really be disruptive if they cracked the final problems ie 250 mile range from a 100 kg pack). Or how about the 11,600 Wh/kg lithium-air couple?
There are some very disruptive technologies just around the battery corner!
Posted by: clett | 22 October 2008 at 07:53 AM
@ treehugger,
EESTOR is NOT vaporware. Lockheed just invested in them. So they are now working with a military contractor on some secret stuff, presumably. There has been definite progress, albeit slow.
The concept works, and it will make its way to commercialization, but more slowly than we would all like.
Posted by: Jay Tee | 22 October 2008 at 08:11 AM
Considering that transistors are only 50 years old +/- and integrated circuitss less, Moores law was a given based on physics.
Useful thermodynamics and IC engine technology is 3+ times that old, as is battery technology. It started in the 1700's with the birth of physics. Way past any Moores Law stuff that comes from moderm physics / quantum mechanics which is barely 100 years old and was a new thing.
A Li battery that had lots of cycles or is a bit more efficient or a bit lighter is incremental change. The theoretical chemical limits on any battery are well known and no matter how you build them you will not have geometric improvements since the limits are close to current technology.
Ultra capacitors, high speed flywheels, batteries, efficient IC engines -- all that have a part and all of them are linear with small changes.
Magic doesn't happen. Spock and Kirk and the warp starship with antimatter engines are pretend. Elon Musk blew up Scotty's ashes this summer and Kirk is a fat make believe lawyer now.
Posted by: JV | 22 October 2008 at 10:33 AM
Yes. Quite a breakthrough. The world has been clamoring for for a battery that only losses 10% of its capacity after 40 cycles. This is totally going to blow away EESTOR and all other lithium batteries. NOT!
It's laughable that folks get so excited about basic scientific work like this. Don't get me wrong. I like reading about it. Nitrated-anode LTO batteries might eventually dominate other chemistries in electric vehicles. However, they are clearly very far from having an actual product. In this sense, EESTOR is far ahead. At least they claim to have tested their product and to be on the verge of production.
Wake me when someone builds a complete nitrated-anode LTO battery with an endurance of at least 4000 cycles.
Posted by: Kevin Cameron | 22 October 2008 at 11:40 AM
Hopefully we can get batteries that will, with negligible wear-and-tear, efficiently store the energy during high-speed regenerative braking.
If we can get compact ultracapacitors from EESTOR that can store no more than the energy from a single high-speed regenerative stop, then EESTOR could have a successful product.
Anyway, EESTOR is not the topic that I want feedback about; here's what I want comments about:
Randell Mills is a Harvard medical graduate who developed a "Grand Unified Theory of Classical Physics" that claims that electrons can exist in stable states below the "ground state" in atoms. He has also claimed to have discovered processes using catalysts that can induce hydrogen atoms to convert into such states below ground state (and such converted hydrogen atoms he terms "hydrinos"), along with significant releases of energy. In fact, his company BlackLight Power claims to have made numerous devices that generate (heat) energy released by hydrino formation - eventually (he says) to produce electricity as cheaply as 2 cents per kWh:
http://money.cnn.com/2008/07/01/smallbusiness/blacklight.fsb/index.htm?postversion=2008070210
Remarkably, BlackLight Power (founded by Randell Mills) has had the claims for their power generators tested and confirmed by well-qualified engineers and scientists at New Jersey's Rowan University:
http://money.cnn.com/news/newsfeeds/gigaom/startups/2008_10_21_blacklight_validates_physics_defying_hydrogen_power.html
http://www.blacklightpower.com/
I've been following Randell Mills' hydrino saga since 1994 (after I saw a CBC documentary on Cold Fusion theories called "Witness").
Sure, almost every professional physicist (e.g., the American Physical Society) rejects hydrinos - and most also reject Cold Fusion.
But many professional chemists (e.g., the American Chemical Society) consider Cold Fusion possible - and they respect Pons and Fleischmann.
I'm neither a professional physicist nor chemist, but like many chemists I believe that statistically significant though mysterious low-energy nuclear reactions can occur within the complex atomic lattices of condensed matter (solids and liquids).
And so-called "Cold Fusion" phenomena can be replicated on demand:
http://www.thaindian.com/newsportal/sci-tech/cold-fusion-success-in-japan-gets-warm-reception-in-india_10053182.html
Anyway, if the BlackLight Power generators deliver many kiloWatts as cheaply as 2 cents per kWh (and safely too), then this could be the biggest energy breakthrough since fire.
On the other hand, if BlackLight Power is a scam, we could end up with one of the biggest energy bubbles.
So would it be mischievous to ask governments to organize first-class top-to-bottom investigations about such BlackLight Power generators??
Would BlackLight Power be mischievous if they refused to cooperate with such proposed investigations??
(And I don't think I'm mischievous for posting such questions.)
Posted by: Jay Dee | 22 October 2008 at 09:05 PM
This guy's experiments can be readily duplicated at any equipped lab anywhere in the world. Rowan University's recent confirmation of exothermic reactions in the 50kW reactor are... astonishing.
Posted by: | 23 October 2008 at 09:15 AM
"I don't believe in disruptive technology for batteries the progress will be incremental."
Interesting. Most people at GCC post notices demanding clean, sustainable, highly efficient machines and living practices RIGHT NOW!! How does non-disruptive, incremental growth resolve these demands??
Posted by: gr | 23 October 2008 at 11:40 AM
I'd like to comment that the lack of comments here is deafening. Sounds disruptive to me.
Posted by: sharona stone | 24 October 2008 at 10:06 AM
Beleivers and Skeptics,
Clearly Moore's Law does not apply to batteries. It applies to computer chips and more specifically to packing more gates onto the same chip by designing and etching ever smaller circuit lines/parts.
In spite of this, some recent Li Ion battery improvements can be considered disruptive. As Clett points out, Altairnano is good for >15,000 deep cycles. Toshiba SCiB 90% good after 3,000 cycles and useable to 6,000 cycles. I don't have information on Ener1 yet. Those are all TiO2 as mentioned in the article. GM's two contenders for the Volt battery (A123 & Saft?) have to meet 5,000 cycle-life and push the car for a minimum of 150,000 miles. Clett is right. Time for us to wake you up Kevin Cameron. We have the battery technology for Extended-Range Electric Vehicles right now. Several companies are ramping up their production. ...and it can only improve from here.
Jay Dee,
Blacklight power is obvious a scam. Why? "since 1994" 14 years and they don't have a demo product? Well then they don't have anything that's worth any trouble. Government to investigate? Why? Isn't it just plain obvious? Companies with miraculous products that can't get anyone to back them, do not really have miraculous products. EEStor has backing so maybe they'll turn out to have something. Proof is still in the pudding ...when it gets served. Steorn is another scam that mysteriously can't find investors. Get it?
Posted by: mds | 26 October 2008 at 11:41 PM