GM-Volt.com: Interview with Dr. Cui, Inventor of Silicon Nanowire Lithium-ion Battery Breakthrough
Dr. Yi Cui
Many of you have heard about the new breakthrough in lithium-ion battery storage. I had an interview with the scientist who discovered it, and hopes to bring it to market, Dr. Yi Cui, Assistant Professor of Material Science and Engineering at Stanford University.
Can you tell us what you have discovered?
The idea is to use silicon nanowires as the active lithium storage material for the battery electrode. Silicon can store a lot of lihtium but the volume expansion is too high, by using nanowires we are really solving the problem of this big volume expansion and we can achieve extremely high capacity, lithium storage capacity with multiple cycles. this is 10 times more than the current technology. So the implications of this discovery is very, very exciting, it means you can have a better battery.
In current lithium ion batteries carbon or graphite is used as the anode material?
Thats right.
When the battery gets charged then do the lithium ions combine with the anode material?
Yes, when the battery gets charged.
Has silicon been tried as an anode material in the past?
There is some research about that in the past using for example a film of silicon. But that doesn’t look as good, because the film peels off right away, because of volume expansion.
Are these nanowires newly created in your lab or have they been around?
People have been making these for a while for transistor applications for example. When I was a graduate student I also worked with silicon nanowires too for making transistors and biosensors. For using silicon nanowires for battery applications, this is the first time. This is a new application for this material.
So nanowires can swell without becoming unstable?
Right.
Compared to current A123 or LG Chem cells, if they used your silicon nanowire technology would they be able to store 10 x as much energy?
Yes, that the idea, they would be able to hold 10 x as much energy in the same amount of volume or same amount of weight. Of course the battery consist of two electrodes, the anode and cathode, you would also like to improve the cathode too to make it happen.
If you just changed the anode to nanowire and not the cathode, would the cathode limit the energy potential storage?
If you improve the anode that just means for the same weight or same volume of the batteries you can use less anode materials, you can use the extra weight and volume to hold more cathode materials and you also improve the battery significantly.
If I take a current battery’s cathode materials and combine i with silicon nanowire anode, I can significantly improve its performance.
Will that give you a ten-fold improvement?
That will not give you ten-fold but it will give you several fold improvement.
In terms of energy density?
Yes.
In the study you published, how many cycles did you run on your cells?
In the paper, we showed 10. If you read the supplementary, we also have the data in there up to 30. And in the lab right now we are testing more and more cycles. It looks like it’s going up and up and up.
For automotive applications, I’m told you typically need thousands of cycles so that the batteries can last 10 years.
Thats right. That’s exactly what we are targeting towards, over 1000 cycles. So since these nanowires are so small they have a way to hold against a big volume expansion, so we will see in the next several months perhaps a year these 1000 cycles, perhaps we can demonstrate that.
So your goal is to show 1000 cycles in as little a 6 months from now?
Yes.
Do nanowires allow for a lot of surface area in the anode?
Yes.
I am told then with all this surface area one could then get a significant amount of side reactions that could possibly limit the lifetime of the battery?
This is the argument typically you take from the graphite anode. This is what people find, you have side reactions. On silicon (though) it looks like side reaction is really minimal. It is highly materials-dependent.
So your saying silicon may have less side reactions than graphite (carbon)?
That’s what we have seen, yes. It has very little side reaction.
So you wouldn’t have to worry about that decaying and thus limiting the battery’s performance?
Right.
Do you think the strong vibrations of the automotive environment would cause these delicate nanowires to be destroyed?
Actually nanowires are much better than big pixel materials. Because if you think about individual nanowires, the gravity or force is irrelevant. And also due to these vibrations and nanowires, because each individual nanowires mass is so small,it just wouldn’t matter at all. Much better than for big materials, for big materials if you vibrate it you might break it. For nanowires, there’s no way you can use the usual vibration frequency to break it…it won’t break.
Since cost is so relevant to developing batteries for cars, are silicon nanowires more expensive? Would they increase the cost of the cells?
Silicon is the second most abundant element in the world. For battery applications it doesn’t have to be high purity silicon. Unlike silicon solar cells which require high purity. the silicon industry is also big, people know everything about silicon. the infrastructure is there, the supply source is there. With the excitement of use of silicon for batteries, the cost will be reduced dramatically.
What about the making of a nanowire?
It can be easily scaled up. I actually did some calculations, the production one could reach with say a factory 3 by 3 miles, you could produce enough batteries for at least 100,000 cars per day easily.
What timeline do you think it would take before your technology could be incorporated into a commercial product?
I am working on it. As a rough timeline, I would say perhaps 5 years.
Are you moving towards your own commercial enterprise to develop this?
I look forward to the opportunity of course. I’m still thinking about what will be the best solution for this technology.
Are you talking to any of the current battery companies, doing something with them or being totally independent?
I am evaluating either way, whether its better to do a start-up company or working with an existing battery company.
Popularity: 70%
(35 votes, average: 4.86 out of 5) 
Loading ...
74 Responses to “GM-Volt.com: Interview with Dr. Cui, Inventor of Silicon Nanowire Lithium-ion Battery Breakthrough”
Leave a Reply
Recent Posts
- GM’s Next Generation Chevy Volts May Use Supercapacitors
- Micky Bly, GM Director of Hybrid Integration on the Running Chevy Volt Prototype
- BIG NEWS from Bob Lutz: First Chevy Volt Prototype Hits the Road and Gets 40 Miles Electric!
- Could Recession Crash the Volt?
- Renault-Nissan To Spend $1 Billion Building Electric Cars, and Already Shows One Off
- The EV-1 Wasn’t Killed, it Was Dead on Arrival
- GM-Volt.com Readership Survey Results
- Continental CEO Thinks They Have Good Chance of Winning Volt Contract
- Lutz: Dynamometer Tests on First Volt Prototype Proving Successful
- Should the Volt Have a Free-Wheel Glide Pedal Position?
Five years to commercialization, huh? Fantastic. Sounds optimistic, though.
Thanks for the interview, guys. Very interesting stuff.
As for implications, there are many. He’s looking forward to 1000 recharge cycle lifespan. While that may not sound like much, remember that a battery pack using his batteries in the Tesla would provide well over 1000 horsepower, and 10 times the range (which is 250 miles now) for a total driving range of 2500 miles. The current Tesla battery pack can be recharged 300 times. 1000 recharges would provide a 2 1/2 MILLION mile lifespan.
There are several obvious implications of all this:
1) with this kind of power and storage capacity, electric tractor trailors are obvious candidiates : everything can go electric.
2) The Volt people have pointed out that, since electrically powered vehicles recover over 90% of the inertia energy in a vehicle during braking, it’s not the vehicle’s weight that’s important in an electric vehicle, but aerodynamic drag and tire rolling resistance that limits
range and efficiency.
The implication here is that size of vehicle doesn’t really count for much in a world of electric cars - both because large is almost as efficient as small, and because fueling costs are so much smaller because electricity is a whole lot cheaper than gasoline. A truck that uses twice the electricity of a small car still doesn’t cost much to operate.
Big will be seen as better, not worse.
Kent #2, Wow. That was very enlightening. At first glance I was thinking that 1000 charges is nothing to write about. But after reading your comment, I see that it is something really huge.
I have a question. How long would it take to give this battery a full charge using 110v? Assuming that I ran it all the way down to the farthest it is allowed to go.
I kind of wonder about the aero characteristics of a Mack truck, though…..
For the Gen 3 or 4 Volt, this will be wonderful!
Kent, #2:
Where did you read that 90% regen braking number? I can see that maybe 90% of braking can be done by the motor rather than friction brakes, but I don’t think all the energy makes it back to the battery. There are bleeder resistors along the way to dissipate energy because the battery pack cannot accept energy that fast. (a combination of batteries a supercapacitors may be able to approach 90%)
That’s what I think is the case at least; please correct me if I’m wrong.
Back on topic though, great interview Lyle. My only fear is that while all of these new technologies come out that improve automotive battery potential, GM may let “perfect” be the enemy of “good enough”. In other words, GM needs to get a functional Volt on the market ASAP instead of waiting on all of these technologies.
Kent#2
Wow, good job putting that in perspective. If you can get that kind of range, you only need 100 full dod cycles for the cars lifetime.
It is nice to keep tabs on new improvements. I think 5 years to beta product insertion is not too far from reality. Many technologies have been moving quicker to market, particularly in the consumer market.
Any improvements that make sense will be quickly adopted by the industry… it is going to be a fiercely competitive space with high stakes. Hang on for the ride.
On lifespan (cycles) and 10x improvement, one should be careful.
Fundamentally, a strain free anode material of silicone nano wires would be very high cycle life. Much like A123’s Nano Iron Phosphate which has very little strain and features >6000 cycles.
Also remember that a PHEV has both a charge depleting stress, and a charge sustaining stress, both which demand very high cycle life batteries to meeet 100kmi, 10 year life requirements (150kmi, 15year life soon required?).
The claimed 10x improvement on the anode material would only garner a 1.5x change in the battery metrics (volumetric or gravimetric power or energy). This is due to the fact that the anode, cathode, separator, and misc stuff all contribute to the volume & mass. So if you super charge the anode, you only minimize the mass/volume of just one component.. not the total system.
Hey.. but a 1.5x change is still note worthy and requires investigation.
How about SEI layer degradation? or electrolyte compatibility? Tell us when you learn more..
Hey Jim I, look to Luigi Coloni (hope I spelled that right) for what he has in mind for over the road trucks. I think by streamlining the cab, (not even touching the engine) an increase of at least 50% in MPG is do-able according to his calculations! I just love this man’s vision & application!!!
Lyle - Thanks for a GREAT interview. This is really exciting stuff, and not just for cars…
I work in thetrucking industry and trust me any real world solution of even %10-15 effifiency is more than welcome. The logistics business is in a recession and most companies are in very big financial trouple. Contract prices are going down while gas is going up. A hybrid or EV truck would be a god send.
Brian M, #5:
Amen!
Our old Impala SS gets about 15 real world mpg in the city and maybe 20 highway. We are now driving it about 8-9,000 miles a year. I am feeling really guilty about using that much gas. I went down to the Chevy dealer today to look at smaller cars, possibly to bridge over to the Volt.
The automatic Aveo gets about 24 mpg city, the Cobalt about the same, and the new Malibu with the 4 cyl engine 1 or 2 mpg less. First of all, this makes no sense to me. Second of all, the mileage of the Aveo is a joke. My old S-10 does that well.
I am not about to take the hit of buying a new car to keep for 3 years, or however long it finally takes until the Volt comes out, if the mileage is not substantially better than these Chevys are offering.
I find this to be really frustrating. Even more so since GM is offering Opels in Europe which get as good of mileage as a Yaris or a Fit. What are we, chopped liver? No wonder GM is getting its butt kicked in the small car market If the Volt schedule strings out for very long, even I will have to start looking at an import.
Also, EEEK!
Dr. Cui looks young enough to be my son. Probably younger than my older one, actually.
Stuff like that makes me really feel like the world is passing me by.
Finally:
Thank God for this brilliant next generation. Grant that they may be able to save the world from the mess that we have made.
Not trying to thread hijack, please forgive me.
James, and anybody else who’s interested, check out this nano-solar article. The lead company in that arena is going into production.
http://www.news.com/greentech/8301-11128_3-9835241-54.html?tag=nefd.top
death to oil, and god bless nano solar
http://www.oiljihad.org
Interesting new battery.
Does anyone know who long it would take to charge once it was drained down to about 30%?
I’m out of here for a week.
Merry Christmas and Happy Holidays to all of
you. I am happy to be part of this crowd.
“See” you in a week.
“There’s a Great Big Beautiful Tomorrow”
The Carousel of Progress
Walt Disney World
There’s a great big beautiful tomorrow
Shining at the end of ev’ryday
There’s a great big beautiful tomorrow
And tomorrow’s just a dream away
Man has a dream and that’s the start
He follows his dream with mind and heart
And when it becomes a reality
It’s a dream come true for you and me
So there’s a great big beautiful tomorrow
Shining at the end of ev’ryday
There’s a great big beautiful tomorrow
Just a dream away
O.Jeff, #16:
Well maybe, but we had better get busy and figure out how to keep from destroying the planet, and ourselves with it, before that great day comes.
As far as recovering 90% of energy during regenerative braking…
Don’t let that let you think that if you drive 20 miles at 60mph and spend X amount of energy, that regenerative braking gives 90% of that all back to you.
It does not.
The energy you get is from the inertia of the vehicle after you remove thrust. You will get a good amount back, for sure, but only a few seconds worth, not the minutes worth that you used maintaining speed.
I think this battery development could be a real game changer. Giving an electric car even a 500 mile range would make it an easy sell. I’m wondering about it’s recharging characteristics - combine a very long range battery with the ability to quickly charge with little to no degradation, and we’ll have something good. The infrastructure will come.
I was watching something on Discovery about future cars, and one guy mentioned that when gasoline powered vehicles were coming to be, everyone was afraid of having gas stations (gas explodes and burns, you know!!) on every street. The cars were made, and the infrastructure grew to meet demand. The same will happen with electric vehicles.
god, that is sweeeet! forget the 5 years, i’ll bet they do it in two and a half…or less!
can you say exponential?
matt 18. “I was watching something on Discovery about future cars, and one guy mentioned that when gasoline powered vehicles were coming to be, everyone was afraid of having gas stations (gas explodes and burns, you know!!) on every street. The cars were made, and the infrastructure grew to meet demand. The same will happen with electric vehicles”….EXACTLY!
anti-oil, tnx for the link! may Allah smile on your many wives, and bless you abundantly with camels and lands. : )
jeff 16. excellent!
I would never buy an EV without a range extender, even if it had a 500 mile range. My parents live 550 miles away and we visit them 2-3 times a year. We also drove our car 860 miles (St. Louis to Denver area) in one day on our last out west trip.
I think a much better proposal would be a future Volt with a 100 mile electric range, 300 lbs less battery weight, and $3000 less sticker price. A 10x improvement in battery capacity would allow this.
Also, I don’t know if an all-new electric filling station infrastructure would be worthwhile. Once E-REVs with 100 mile range go mainstream, we’ll be consuming about 1/10 of the gas we use now. I’m not sure it’s worth building a whole new electric infrastructure for that last 10%. But hey, I don’t think any of us are clairvoyant, so who knows?
Dave 23,
You have to look at it from the reverse perspective.
From the driver’s standpoint, it may not seem worthwhile for the filling stations to transition toward electricity just so that we can squeeze the gasoline out of the last 10% of the miles.
But it’s definitely not worth it from the filling stations’ perspective to stick with gasoline and resist adding rapid charge points if they’re only fueling 10% of the miles.
If 90% of the miles are electric, then the only way the filling stations can remain profitable is if they start selling electricity. It’s a simple matter of satisfying the predominant demand.
I cannot imagine EREVs dominating the market for any significant length of time. As the battery technology increases the ratio of electric miles, rapid charge points will spring up to meet demand and keep the filling stations in business.
Ultimately BEVs will take over due to reduced cost. But BEVs will never come to dominate the market until EREVs already have.
Here’s a youtube of a Phoenix motor car using the Altairnano batteries. Real people driving a real Phoenix car. Listen to the list of features in the car, notice there are four people in the car that has four wheels. Notice the range and energy capacity of the car. There is also a comment about how efficient there regenerative braking is. GM is moving a bit slow, 2009 or bust.
http://www.youtube.com/watch?v=ZuhbfSfCzXs&NR=1
Found another Phoenix youtube where a representative talks price, an upcoming battery expansion pack, and future vehicles to be produced.
Nope, Volt production in 2010-2011 just won’t cut it.
2009 or bust.
http://www.youtube.com/watch?v=QyLvQ4OK_W8&NR=1
lylel 26. i agree 2009, h*ll i’m still figuring they’re going to have something out by the end of 2008…but, i can’t agree on the “bust” part. but, let’s see how things go.
People are so used to cheap electricity from their homes…how much would filling stations charge for it? The same amount? Or would they be able to charge more because they would have the rapid charging capability? I wouldn’t get an electric car just to pay for overpriced electricity where I used to pay for pricey gas. I want fast charging at my house. Though I guess for long trips I might not have much choice.
LyleL Says:
“December 21st, 2007 at 10:36 pm Quote
Here’s a youtube of a Phoenix motor car using the Altairnano batteries. Real people driving a real Phoenix car. Listen to the list of features in the car, notice there are four people in the car that has four wheels. Notice the range and energy capacity of the car. There is also a comment about how efficient there regenerative braking is. GM is moving a bit slow, 2009 or bust.”
*****—****—-****
Phoenix does not yet have a car out. They are a small company, and IIR Altair nano has fallen short of their performance boasts.
The vehicle will not be priced below $45K, has no range extender and being a small company, they again -IIRC- have NO warranty.
I hope they do produce this vehicle, and I hope it comes out when they say it will, but they’ve only just recently decided on a manufacturing partner, and have a very steep hill ahead of them.
BUST for GM?? No I don’t think so. This company like Tesla is going to have to fight for survival. The good thing is that they’re serious, and for EV’s there is no turning back.
[quote comment="21019"]On lifespan (cycles) and 10x improvement, one should be careful.[/quote]
Thanks, finally someone else with battery knowledge posted his opinion here.
As you pointed out, the whole rationale behind this is to reduce the thickness of the anode and free the volume for more cathode, thus improving the cell capacity. If a new anode material has a capacity >3000 mAh/g with similar tap density, the derived anode will be very thin and you probably will get a boost of capacity about 50-80%, that’s it. Those who do not know the battery design can remember this: Even if the anode capacity is increased by a factor of 100 or 1000 times, it does NOT mean the battery capacity will increase that much because of the limitation by the cathode and other ingredients in the battery, the theoretical increase can only be about 100-150%, no more.
Now let’s check the reality. The supplementary info accompanied the paper shows anode thickness to be about 60 nm (NANO meter) and I estimate the loading (weight of anode material per square centimeter) to be only 0.1% (OR even less, I assumed a density of 1g/cc for the nano-wire, which is probably an overestimate). It is WELL know when you decrease the loading from a commercial value to a small value, the prototype half cell performs very well, but when you MUST increase that by a factor of several hundred to build a commercial cell, you will definitely lose the performance cited in the paper, that phenomenon is an unfortunate issue virtually can’t be addressed. The declaration of being revolutionary is ridiculous unless he also tried much thicker electrode and still preserve the performance and HE should have tried that and published the result. The reason for the good performance published in the paper is because lithium cation diffusion distance is only 60nm while in reality that distance is about 50-80 micrometer, which is about 1000 times longer. This is like a young guy can carry a 2 lb steel rod and run, he won’t be able to run if he carries a 2000 lb steel bar. You could argue that he can put the steel bar in a heavy truck and drive, but there is no similar mechanism in a battery design.
Other issues: The nano wire is inherently fluffy and has a low density compare to graphite. Because silicon reacts with lithium to have a theoretical volume increase about 300-500% (do not remember the exact value, but something like that range). If the electrode is not compressed during manufacturing, the advantage of capacity increase (per unit weight) is severely compromised, if the anode is compressed (standard process in any commercial cell), the volume expansion can severely damage the cell. One possible solution is to dissipate graphite into the void space of the anode to mitigate the problem, this strategy is used by SONY in their camcorder batteries ( Sn-Co-C anode), but implemented differently.
Still more issues (which I believe potentially can be solved.)
1) Good control of the nano-wire growth, it has to be uniformly coated onto Copper foil and has to be on both sides, not single side. Any spot with lower amount of nano-wire can potentially become a spot where lithium dendrite forms, thus causing safety issues.
2) Cost issues, I am not familiar with nano-wire growth and can’t comment too much on that.
3) Possible side reactions between Silicon nano wire and other ingredients of the battery, SEI formation.
4) Cycle life, it is not clear from the paper, initial results looks interesting, though.
The author should try this with much thicker nano wire deposition on the substrate, from the published data, it is highly unlikely he can achieve even a moderate performance.
As for the battery made by A123, their m1 266520 are hand-made using multiple tabs to boost performance. Yes, they are by far the best LiFePO4 cells made by any company. Now they make the big EV cells, I hope they do not use tools to scratch the electrodes in order to put more tabs (scratching can introduce particles which shorts batteries, like SONY), because the battery consistency will suffer and affect battery life, even though a single cell can perform beautifully. However, considering they were selling m1 in 2006/2007, it will be difficult to switch to automatic product line to weld tabs using a Japanese machine, this kind of transition usually take long time and I hope someone from GM asked them this question. I know there are lots of bashing against Toyota on this forum, but Toyota has far stronger expertise in battery R&D (JV with Panasonic) and still Panasonic had battery recall, I find it funny for Bob Lutz to laugh at Toyota when some small companies provide the Li cells. I am wondering if the PHEV package can last long enough in real tests.
To clarify those issues brought by me, please ask the following battery scientists:
1) Dr. Khali Amine phone: (630) 252-3838
2) Dr. Michael Thackeray: (630) 252-9184
3) Dr. John Goodenough: (512) 471-1646
4) Dr. Yet-ming Chiang: (617) 253-6471
5) Dr. Jai Prakash: (312) 567-3639
6) Dr. Glen Amatucci: (732) 932-6856
PS: It’s good to be modest to other people and be aggressive inside, well, Bob Lutz and GM do not, that may explains why GM’s fortune fluctuates like the currency of poor African country while Toyota has NEVER lost money in the past 50 years. DO NOT underestimate Toyota, they had problems (even fire), but they are highly competent and will NOT let GM take the lead!
#29 Grizzly - Phoenix will not be in the same market segment as GM for a long time. They will initially focus on fleet sales (and make a lot of sense for those fleets). But I’d love any source you have for Altairnano’s batteries not living up to their claims. Everything I’ve seen by independent testing is meeting their claims. They just have a cost problem. If they can either develop a lower cost sub relationship or build their own larger and more cost-effective manufacturing plants, then their battery is the one to beat. Until then however no major can consider using them.
I’m not competent to comment of lifepo4’s rather illiterate criticism of Cui’s claims - there wil undoubtedly be many
in future giving their take. However, his claim that Toyota is really smart about batteries because they are “really smart” about selling cars is the argument of one of the Stooges, not an educated person. WE have seen Toyota’s “inteligence” about btteries - it wasn’t Bob Lutz comments that led everyione, including me, to conclude that when it coers to batteries, while they may have bright engineers, there is no reason to assume these people know much more about battery technology than their executives, who have surprised a lot of folks with their sheer ignorance about the technology. Toyota is talking plug-ins with an 8 mile range and Honda practially denies that plug-ins will have any value. Toyota itself claims it won’t have a plug-in before 2012, so I guess this fellow is calling them liars (which everyone else did a few weeks ago when they were claiming GM’s batteries were dangerous, etc.).
Some of Kent’s remarks are way off IMO in regards to Toyota’s technological and market savvy, and in general I find lifepo4’s remarks much closer to the truth. What Toyota says and what Toyota DOES (usually in secret) are two very different things. Remember, this is a company that denied having any interest in a PHEV until very recently; since then it’s been revealed that in reality Toyota has been working on this technology all along. Hmmm…
And can any reasonable person buy Kent’s statement re the “ignorance” of Toyota/Pansonic EV’s battery tech when their NIMH packs have been very close to 100% flawless in the Prius, even in cars with well over 100,000 miles? This is pure Jap-bashing nonsense IMO, and has no place on this forum. It appears that the only reason Toyota is holding back on using lithium is that the company will not accept any less bulletproof performance from the new chemistry than from the tried and true–and still improving–NIMH packs. The word is that the next gen Prius, due out in fall 2008 I believe, may boost efficiency by as much as 30% (with NIMH no less), which is remarkable. By buying majority interest in the battery division of Panasonic several years ago, Toyota wisely assured themselves a prime mover place in the field of battery hybrid tech, and they’ll be reaping the rewards for many years to come. Their market prescience, technological savvy, and shrewd investments are indeed the signs of a leader, and I’d bet good money that Prius will be a full-fledged mature brand with several models to choose from before the Volt ever hits the showroom floor. And push the HEV efficiency envelope far enough and the PHEV vs HEV debate becomes meaningless IMO as consumers will go with the proven leader, especially if costs can remain controlled.
I am someone who is actually designing Li batteries and have actual experiences in watching how batteries are made, so please do not say st***d things like that.
One thing I feel about GM (based on my expertise) is that they underestimate the difficulty. Yes, A123 battery performs very well, if you check their data, it has something called BSF, which means they test a single cell, but simply magnify the data by a factor of several hundred and show the test, this is fine in discussion, but when you put 200 cells together, ensuring the uniformity is paramountly difficult, and any small inconsistency over extended period may lead to premature aging for one particular cell over another. Since A123 USED manual process to make m1, I hope they DO not make 32 series in the same way. Even one company can make the cell 99.99% consistent, when you put the 200 into a pack, you must ensure that their thermal environment is the same. Put it this way, if you put 3 cells like ABC, B will always be 2-3C higher than the other two, after several years, difference starts to show up and BMS has to work hard to ensure consistent SOC, this is because when one particular cell has low SOC, it may go to charge reversal and fail or even explode. This is a less issue for HEV, but serious challenge for PHEV due to much higher SOC swing range. To tell you the truth, first generation of Prius is not particularly good in this respect, but fortunately NiMH is a little less sensitive to temperature than Li-ion. One reason why A123 performs well is they have more tabs. The Japanese do not use multiple tabs because the machine can’t be designed to do this, so they choose single tab and reduce the coating thickness to achieve performance (energy density compromised). With recent recalls, they will be even more careful. The battery coating room in Japan is like clean-room in semiconductor industry, virtually power-free, and occasionally problem still shows up. I do not know what it look like in A123 facilities. One thing funny is A123 has a Canadian division to make battery packs, yet they choose to work with Continental on battery pack. As for the CPI/LG, they use LiMn2O4/graphite, this battery is also safer, but performance degrades a lot under higher temperature and PHEV battery will often experience higher-than-normal temperature.
Toyota is working aggressively on their development, they are not testing Li ion on a vehicle simply because the cell reliability does not meet their demand, AND in fact, I believe there is a small chance that graphite based Li battery may never will. GM has no real battery experts in battery manufacturing and engineering. You know that American CEOs often boast about certain thiings due to short-term pressure by media and Wall-street, but they often under-deliver.
Battery in EV/PHEV is far more complicated and difficult than you might think. Americans have a tendency to be optimistic about everything, but I advise you to be a little cautious on this front. When it comes to some quick business (youtube, google, Apple iPhone), they are doing good, but certain things need dedication and long-term planning and mouth shut-up, and the Japanese excels on this. GM might get Volt out earlier, but who knows. If both GM and toyota have their PHEV out, who will have a better reliability? Remember, when 1 out of one million fail (DELL), SONY recalled battery. You need to ensure 10000 better reliability on PHEV battery, because if Toyota have one milion PHEVs, they will need 200 million cells. If one of them fails and blows up, it will be headline on CNN. Three-mile island incident does not kill a single person, but kills the nuclear power business in this country. For something like PHEV, it is better to be cautious than sorry later. And Tesla will learn this hard way in the future!
It’s you who are ignorant, the moment I heard the news about this paper, I got it and I digged deeper. Someone like you to say my comments are illiterate is simply c**p. I have been doing this for almost 10 years. Cui Yi does not have expertise in battery and certainly not the details required in battery design. I do not blame him on that, but I just hate someone hyping sth when it is clearly wrong.
Don #29, no question about Altair’s safety, but I remember something about their batt’s potency being overstated. I can’t find anything on it and I could be wrong, but I will say that it wasn’t more than a month ago Phoenix was claiming 300+ mile range for the Pickup and now it’s down to 100.
It does look like a nice truck, however my response was geared toward addressing the fact that its release won’t affect GM.
You are correct about the fleet sales, but even still they’re going to struggle to make money.
In reading these posts, I have to say lifepo4 knows what he’s talking about. Having met the design engineering team from Taiwan who patented our LiFeBATT 40138 large format cell and discussing the technology with them @ the recent EVS-23 Show in California, I can assure you he is very much “on target”. Also, Toyota has just recently invested in the new LiFeBATT factory for a percentage of our production of the 40138 Cells in 2008. They did so after independently testing our cells and finding them to be worthy of their investment.
Don Harmon
As far as the regen breaking efficiency goes Tesla actually had a post on their blog about the magic of the regenerative breaking, and they were saying it was about an 80% battery to wheel efficiency rating, and then whatever % it can return from the inertia back into electricity, and then again another 80% efficiency from wheel back to battery again. I’d guestimate probably 30-50% total efficiency in the regen, since I dont know how much energy from the regen brakes is lost to heat.
As far as the comment about the Tesla cells goes, I’m not sure what the comment was aimed at. They’ve done tests where they induced single cells to the point of combustion and it hasnt spread to the other cells in their battery so they wont have melt downs for the cars…… now of course how well the battery holds up over the years I cant speak to, but safety doesnt seem to be a factor with their design.
lifepo4 #’s 30, 34, 35.
Your technical expertise is obvious. Just wish I could understand what the he** you just said. Some of us need things explained in simpler terms.
lifepo4-
As far as I know, A123 achieves their performance not just through multiple tabbing but through increasing conductivity of the cathode. There’s some debate about the exact mechanisms that do this, whether it’s the doping agents they add or it’s just that their doping agents have some carbon-containing precursor molecules as an impurity that actually happen to increase conductivity.
They’re also not using 32-series for the Volt - they’re using a custom prismatic cell, which’ll be more space-efficient than cylindrical but more expensive to manufacture (although with larger cells maybe the $/Wh will balance out). So that’s something GM needs to be careful about.
That said, IF this new technique using a silicon anode has comparable longevity compared to graphite (keyword:if), an increase of 50%-80% capacity is still nothing to scoff at.
Thanks, AES. I’m glad A123 uses prismatic instead of cylindrical cells, it’s better in terms of spacial efficiency. I hope the cell is not too thick because of potential heating issues. I am aware A123 used some type of “coating” technique. Because they switched from cylidrical to prismatic, I am curious how fast they can improve the process in order to make high quality cells, this kind of switch takes lots of time to perfect.
Now to AES and Estero: In order to explain it, one need to understand how Li battery is made. Both the anode and cathode are made by spreading active material (with polymer binder, etc) onto copper and aluminum foils, respectively(both sides), then both of them need to be pressed by using a rolling machine to make the materials stick to the foil. To get higher energy (more range for the EV), it is important to ensure the coating is relatively thin while the weight per square centimeter(called loading) is relatively high. Depends on the chemistry (what material is used) and cell design (high power or high energy?). There are certain ranges for both the thickness and loading values that are usually determined by lots of experiments. Of course there are other issues such as uniformity of thickness& loading, etc which determine the product quality, I will neglect the uniformity issue to simplify the explanation. It is also well established that when you reduce the amount of loading, the battery’s performance is much MUCH better, at the expenses of energy. Because the published result is less than 1% of the loading required (here the higher capacity of Si is taken into consideration, the actual weight/cm2 of Dr. Cui’s anode is only 0.1% of commercial value) to make commercial cell. When I look at his data, the performance is barely OK. When you MUST increase the amount of Si per square cm by a factor of several hundred, it will be nearly useless.
Another issue I mentioned earlier is the shape of the material. It is tubular and have lots of space between the tubes. This is NOT good. When you design the battery using this material, you HAVE two options: 1) Increase the anode thickness. 2) Decrease the loading of cathode accordingly (If you do not, battery will fail). Either way will decrease battery capacity. This is why: For a specific battery size, the volume is fixed, both 1) and 2) dictates that you MUST put more aluminum and coper foil, thus reducing energy. You may ask this, can we decrease the thickness of copper and aluminum? answer is NO, both are already close to the minimum and CAN’t be REDUCED further.
I am sorry that my explanation is not good enough, because it is really difficult to explaain a complicated thing. This is like this: If I punch your nose with my fist, how can I convince you that the force on your nose and my fist are equal? You will never believe SO unless you have physics background.
Oh, I forgot one thing here: A123’s active material is also called nano material (I do not consider it nano, but its size is smaller than usual), why is that? Because they CAN’T make the material to perform without making the particle size that small (Their loading is within normal range, not 0.1% of regular value). I can assure you that if A123 can make their battery to perform w/o making their battery material particles very small, they will absolutely do it. A123’s material is LiFePO4, which is horrible to make good and consistent coating, personally I am not sure if they completely solved the coating problem.
Here is an interesting story about Toyota.
http://www.sfgate.com/cgi-bin/article.cgi?file=/c/a/2006/04/24/MNG3JIE6DK1.DTL
Based on my knowledge, I must say that Toyota is extremely aggressive in product development and have a strong self-respect, but they rarely show it, especially when Detroit three is in trouble. Both A123 and LG/CPI have never shown the battery pack’s life. I do not know what Toyota is doing now, but I am sure they are aggressively working on it. With personal uses of both LG and A123 cells, their manufacuring is sloppy even compare to SONY who has a big recall (I never see Toyota’s battery, presumably similar or even better than SONY) I am curious to know what will happen next year, does the battery maintain the performance under aggressive testing at GM or they degrade relatively fast. Bob Lutz’s boasting here make me sick. I’m not saying Toyota is surely to lead this time, but with my battery expertise and knowledge (I rarely sleep before 12:30AM, and I am learning as much as I can), I would rather bet Toyota will lead again, and of course, only time will tell.
To Lyle: Please consult with the following experts in batteries, Dr. Spotnitz is well known in battery design and Dr. Anderman is the formost battery expert in automotive applications.:
1) Dr. Robert M. Spotnitz, rspotnitz@batdesign.com
2) Dr. Menachem Anderman, info@advancedautobat.com
Look at Bob Lutz:
http://www.reuters.com/article/Autos07/idUSN2062690720071121
lifepo4 has many insightful comments although his/her estimation on nanowire loading is way off. It is not 60nm thick but at least 2000nm ( Si density 2.3g/cc) if you redo the calculation. Therefore, I would say that mass loading is fairly promising.
While all these “new” chemistries seem valuable and certainly worth developing, the HEV / PHEV market needs a viable battery NOW to succeed! LiFePO4 seems to be the best choice if you weigh the saftety and the life expectancy plus the robustness of this battery can only increase and it is HERE right NOW! I can see no reason why the EV industry just doesn’t jump on this right now and start delivering product instead of searching for the “holy grail”?
It’s here NOW everone! It’s called LiFePO4 and you will be seeing it soon in all the new EV car ventures.
[quote comment="21702"]I hope the cell is not too thick because of potential heating issues. I am aware A123 used some type of “coating” technique.[/quote]
If the cell they showed at EVS is anything similar to the production version, then that would make it about 3/4″ thick. I have a lot of close up photos of that “show cell” that I took at EVS if you want to see them. It also had lots of corrugations on the external case that sort of resembled a mini heat sink, and might provide some room for minimal air flow if the cells were stacked together.
AES - There is very little heat generated in our LiFePO4 cells and the case you saw @ the EVS Show was an early prototype. The new cases are much smaller and based on a module of (4) Cells = 12V / 10Ah. including VMS & GBST on-board.
Don Harmon
http://www.lifebatt.com
I was referring to the A123/GM co-designed cell, but it’s good nonetheless to hear that lifebatt’s cells are performing admirably.
O.K. Am I to understand that the LiFePo4 battery is manufactured “BY” Toyota or manufactured “FOR” Toyota? If Toyota is using a manufacturer, who is it? Did Toyota take into consideration “where” the product is being shipped from? A portion of the cost (albeit, a small portion, but a portion nevertheless) of shipping can be reduced if the manufacturing plant is somewhat close to the assembly plant. Hello GM USA… take a hint in cost consideration/jobs.
Toyota would be buying into the LiFeBATT production line for 2008. Product is produced in Taiwan and would be shipped to Japan. Distance from the two is not a big factor in the equation.
Don Harmon
I believe Toyota is currently working with Panasonic for their batteries.
[...] Very good interview here: GM-VOLT : Chevy Volt Concept Site
Where is all the lithium going to come from? We could be trading peak oil for peak lithium. Read an excellent discussion here:
http://www.meridian-int-res.com/Projects/Lithium_Problem_2.pdf
And look at how the price of lithium has begun to climb:
http://minerals.usgs.gov/minerals/pubs/commodity/lithium/450798.pdf
http://minerals.usgs.gov/minerals/pubs/commodity/lithium/lithimyb06.pdf
B.C.
.. I’ll do anything to save the planet, except take a science course.
This guy (Yi Cui) may not be trustable.
He is a “supposed-to-be statutory rapist”. Two year ago, he deceived a 16-year old girl into sex when his wife was pregnant. That time he was a PostDoc in UC Berkley. That little girl then got pregnant and had a child afterwards. He somehow successfully avoided statutory rape charge and post, but many Chinese people know the story behind. Ask a Chinese friend around about this story. It was sick.
Now I seriously think this so called “10 times better battery” news is just a PR strategy used by this guy to fool media and to make him an innocent “scientist”.
Ask any serious battery scientist, is 10 times better theoretically doable ? if not, it’s a deceit. regardless of if 1.5x or 1.0x is possible or not in the future.
It’s a deceit, because he knows the architecture of the battery, yet he claimed 10x more density.
Interview Quote : “If you just changed the anode to nanowire and not the cathode, would the cathode limit the energy potential storage?
If you improve the anode that just means for the same weight or same volume of the batteries you can use less anode materials, you can use the extra weight and volume to hold more cathode materials and you also improve the battery significantly.
If I take a current battery’s cathode materials and combine i with silicon nanowire anode, I can significantly improve its performance.
“
Let’s say…..here we are! We are now driving electric vehicles w/ lithium batts, and with some of the earlier posts (Bill Carson) brings up a very good senario. Are we trading one resourse for another? I just heard about a lake in Chile’(mid 2007)in which a fischer (sp?)opened up under the lake and it took only about 2 months to drain itself! What if we are well into the electric vehicle sales and lifestyle…..then we lose this (or similar) lake somewhere in the world? Our planet is always geographically changing, and we must look further into the future 50 to 100 years when embarking on a scientific search for alternative fuels. After reading about 1/3 of the post from Bill Carson, (I’m by no means a scientist, the reading got to be a bit much) this must be a factor in deciding if we are going to hang out hats only on lithium. This presents a situation where 5, 6, 7 or 10 years from now, what will happen if one of the major lakes drain? How will that affect this industry ($$) and most of all… the PEOPLE! Is there enough resource on our Mother Earth? Where is the backup? Now that we have reduced the demand on oil, what happens to the price/gallon? We will not, in my lifetime, be totally off the need of oil…somewhere. So, simple supply and demand tells me that the oil companies BETTER be working very hard to come up with alternative measures. We are now using less oil, so in order to keep the oil companies profitable, they will raise the price of oil or have to have other energy in place to counter any volitility in the future market. Let’s remember, the ONLY job the oil companies have is to keep the profits up for their investors. And at what expense….US?? You can’t tell me that everyone is making such a fuss about 40/50/60 miles on a charge! Check the average miles driven to work only in your area(not to the store, family obligations, school activities (games & practice), hobbies, worship, vacations or anything else outside of miles to work. We would have to drastically change the structure of how towns and cities are designed. If we could not get to where we need to go because of the lack of “miles of charge” in our vehicles, then we would have to rely more on public transportation….Hmmmm, does that mean we go to the “new 2000 something” version of “electric” trains/streetcars? Understandably, it takes resources to produce the power that goes to the public transportation! And there again, we are relying on inventive minds to come up with a solution, and allowing the “powers that be” now to encourage and support them rather than hold them back. You know, I remember hearing something about a 70 mpg “carb” back in the 60’s. What happened there?
In 1993 my girlfriend had a zippy, fun to drive carburated (sp?) Geo Metro. We took a 2200 mile trip through Montana, Wyoming, Colorado and back. We averaged 44 mpg and 51 mpg on one tank.(Fact!) I don’t understand why that seems so unatainable today…15 years later!
My wife drives 20-30 miles everyday and a 40 mile electric would be in our driveway TODAY if it were available. I however put on many more miles than her but would still enjoy the torque and smooth acceleration of a series type hybrid, not mention the carbon free first 40 miles.
I don’t want to see excessive “must haves” delay the production of the Zero emission capability we have today.
Lastly, our electric infrastructure will be forced to respond as demand increases and I don’t think we’ll be to quick to build large carbon producing power plants but will likely lean towards cheap clean nuclear, solar, wind, hydro, etc. France gets 80% of their electricity from nuclear power.
This forum is fantastic. A personal thank you to all contributors, especially Yi Cui, lifepo4 and Don Harmon. I’m a BEV experimenter and am looking forward to seeing the prices go down as they are now just starting to do. As experimenters, we undertake quite a bit more risk than your average driver. Have you heard from others in the EAA yet.
Still a lot of bad blood over the EV-1 but a group that has huge market potential.
http://www.eaaev.org/
Charging into the future.
[...] This is an interview with the researcher on this. He sounds pretty pumped up about it all. He explains how they work and gives some statistics. Says it will be 5 years though till they are practical. GM-VOLT : Chevy Volt Concept Site
The nano wires would also be applicable to nickel metal hydride. This could change the game for nimh is a proven, long lasting cost effective and safe choice. Now you could get the power and weight specs too.
@ lifepo4
Thanks for your in-depth technical view on this topic, but i do also have a question.
What is your opinion about Altairnano’s Lithium Titanate battery?
A little technical in-depth view on this battery type would be great.
Standardised charged batteries sold in multiple plug in units.
Instead of fast charging, an ergonomic and safe
exchange of discharged batteries for charged.
Some local solar charging.
Hopefully battery tech will increase milage between exchanges.
Regular emergency credit card/coin high speed recharge points on roads.
Recycling of batteries localised to exchange stations which would logically be the current gas stations. Then again with land availability and some capital, solar farms charging batteries could bring some new players into energy supply economics.
I admire these inventors and civilization depends on them so when greedy persons who may lose profits should new inventions succeed and this may often as not cause the greedyd ones to try and maybe succeed in quietly killing off the inventors.this possibility was pointed out as having likely happened at the Charlotte airport as a battery inventor was waiting in his car.The means of execution was a new invention also .A ray gun designed to cause the heart to fibilrate and cause death.
I think Mr. YiCui has been snooping around other people’s work. Could it be that he’s a Mr. Copycat? I’m quite familiar with the work that Hughes Aircraft was doing in this Lithium-ion science, which started around twenty years ago. As well, they were producing nono wires of various types. I don’t wish to get into this further, lest Mr. YiCui get more “original” ideas.
An event occured a couple of decades ago when Michael Armstrong was running Hughes. He promoted a “technology exchange” program with China that was mainly conducted at the Hughes Malibu Research Center. One may ask, what did China have to exchange for what they got from Hushes? Answer: Nothing. It was strictly a one-way exchange. One may wonder if Mr. YiCui was in someway connected with that program.
Take note that China hasn’t come up with an original idea in several hundred years, and has NEVER produced an industrial patent.
just watch who killed the electric car
UMMMMM…I guess you haven’t heard about the capacitors developed by EEStor…No problem…here’s a link./
http://www.ultracapacitors.org/
If one goes and look into the technology, it is the energy storage, i.e. battery that limits current electric vehicle feasibility. With quantum developments in battery technology like this, that limitation becomes less and less of a problem. Add regenerative braking systems that convert braking energy to charge the batteries, and the range limitations inherent in electrical vehicles is looking increasingly less like a serious obstacle.
[...] would need less assigned to the anode allowing a larger cathode which offers a large improvement. Dr. Chi offers that it wouldn’t get the media claims of 10x but would offer several times the [...]
[...] nano-breakthrough won’t take 10 years to realize. Could make a huge difference in cars like this. GM-VOLT : Chevy Volt Concept Site
This has been a great site, good info, knowledgable contributors. HOWEVER, can we lay off calling each other s****d and other c**p badmouth names?
There seems to be developing momentum for EVs, BEVs and PHEVs. We must get off the oil teat, now is better than when there is no more. Electrification of transportation and renewable distributed generation by wind, solar, geothermal, etc. with a robust grid, is needed.
The only obstacles seem to be oil companies, coal companies and short-sighted (I refrain from saying dull-witted) auto company management. I give kudos to GM for their efforts, I hope they succeed, and I hope they do it in the midst of a flood of competition.
Gas stations, electric stations….they will go the way of the buggy whip!
If electric cars go 200 plus miles between charges, then there is to little trip traffic in the 200+ mile traveler to be profitable. Truckstops along interstates will servive because drivers need to eat, sleep, snack, and recharge!
God bless Dr. Yi Cui! (And Lord, watch his back)
[...] folks at GM-Volt have interviewed Dr Cui, the inventor of the new silicon nanowire lithium battery technology that may allow for 10x [...]
[...] http://www.gm-volt.com/2007/12/21/gm-voltcom-interview-with-dr-cui-inventor-of-silicon-nanowire-lith... Keine Kommentare bis jetzt Einen Kommentar hinterlassen RSS Feed für Kommentare zu diesem Beitrag. TrackBack URI Einen Kommentar hinterlassen Zeilen- und Absatzumbrüche automatisch, E-Mail-Adresse wird nicht angezeigt, HTML-Tags zulässig: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong> [...]
as always I am reading this and thankful that you all are so much into it as i am. i’ve been dreaming for years of how to build the perfect electric car. the only problem…money sorry guys i don’t make much and the biggest problem i have is seeing the uses of all the multitudes of science and tech that is out there. the battery’s lifecycle and lack of charge capabilities is a limiting factor yes but once altairnano came out with there lithium titanate battery my ideas became possible(except for the money part) these new batteries as said earlier allow for up to and possible more than 6000 cycles as well as burst charge/discharge. which means that the regenerative braking would work more efficiently because the battery pack could effectively absorb all of the energy extracted from it. also, what infuriates me is that no one wants to listen in the big industries to the little guy that just might have an idea. and i’ll tell you guys cause you sound actually pretty awesome(even though some of you don’t agree) but why hasn’t someone said “hey a hybrid doesn’t have to be strictly gas and electricity” india has a company called tata group that is producing an air powered car that gets upward of over 100mpg equivilent that’s not including the boasts of the zero pollution motors that is set to bring out the same type of vehicle in the states that is rumored to get a 1000mpg equivilent. but when you look at what i just wrote that is strictly an engine run off of air not a hybrid. your right and here is where the hybrid part comes from….a few hybrids that do well currently use a small gas engine as a generator to resupply the batteries with electricity. so why if they have an engine that can get a 100mpg equivilent with just air are they stuck on hybrids being just “gas and electricity”. for pete’s sake just use the air engine as a fr$$kin generator to re supply a battery pack made up of A123’s Nanotechnology batteries(altairs lithium titanate design) which can handle burst charges that come from the regenerative braking. wscpecially when you have new electric pancake motors being produced that have better torque and horsepower than we have seen in the tesla roadster. IE Rasers “P2″ Pancake motor. ahhh i’m done for now but if you actually read this and can give me any technical opinions as to anything you want to say please email me at jokerswild52@yahoo.com but remember i get alot of c**p in my inbox so if you do email me please include a subject relating to this battery technology ok. thanks
oh, also lifepo4 you really do know alot and i’m not trying to say anything mean but the research that read on altairs nanotechnology batteries was pretty good and they used lithium titanate for those batteries. it’s been a while since i read the research but it’s very intersting and they did test it very well. i don’t know about pheonix motors and their boasts but altair as far as i know never said anything about increased capabilities other than the burst charge/discharge only that due to the new design of it that it was significantly safer(ie it didn’t over heat when under extreme stress, thus meaning no more exploding batteries) than the standard li-on batteries.
When I read the news about Dr. Cui’s lithium ion breakthrough a few months ago I knew it would have far reaching impact. Up until now battery improvements have been gradual, but this will put battery technology on the leading edge of change for automotive and other industries.
We are all craving an electric automobile with a reasonable range and battery lifecycle. This development without question can make that happen.
Goodbye big oil.
PS Vote out any member in Congress who stands in the way of change. It’s your duty for a better tomorrow. You wouldn’t believe how much developments like this irk the oil companies and those in Congress they have bought off.
We can do it NOW! Dr. Cui’s breakthrough, if it can be scaled up and made into a production item, remains to be seen. This is a good sign and I wish him the best, but we have the battery tech. already being mfg. It’s called LiFePO4 developed 10 years ago by Dr. Goodenough @ the University of Texas. It took this long to be ready for the market, but now watch out! Electric Cars are going to be the way to rid our economy of fossil fuel forever. The time is NOW!