Li-Ion With 300% More Power, Minutes to Recharge

Battery Nut writes "Altair Nanotechnologies claims to have found a way to reduce Li-Ion recharge time to minutes, as well as increase battery power by 300%, according to this press release. Seems they have received some good feedback by certain experts about thier work: "Two eminent experts in battery technology, Dr. K. M. Abraham and Dr. Vassilis G. Keramidas, have expressed strong support for Altair's work. " So is it a new revolution in battery technology, or hopeful hype? Stay tuned, their quarterly conference call is Thursday Feb 24th at 11AM." Anyone else think snake oil?

Comments

Snakeoil????

[lecithin]

Not everybody thinks so. Altair's stock has gone from $2 to $4+ this past week. It topped out at over $6 last Friday. Their average volume is at 6.6 Million. Yesterday, they doubled it.

Hmm...

[Anonymous Coward]

"Anyone else think snake oil?"

Someone's trying not to look so stupid this time around...

Hmmm...

[clawDATA]

Maybe it uses cold-fusion?

Slashdot: home of stock pumpers?

[Takeel]

When did Slashdot start posting messages from stock pumpers?

Re:Slashdot: home of stock pumpers?

[m50d]

Since Taco realised he could buy the stock just before posting the story? :)

Seems almost reasonable

[Anonymous Coward]

According to the article, they use a Lithium titanium oxide nanomaterial. Best gues, the nanocrystals typically have little or no stress and a low defect density, as well as an extremely high surface to volume ratio. All of these should improve the efficiency and speed of the battery operation. This might also increase the speed that the battery can discharge. Of course, I am not a battery specialist. Just in nanomaterials development. Might not be snake oil. Assuming all the accolades are true... well, Altair doesn't have a reputation for falsifying data. I look forward to seeing this develop.

Re:Seems almost reasonable

[Alceste]

That's actually not true. Nanometer sized crystals have large surface to volume ratios than bulk crystals, creating more surface defects per unit mass. The defects within a bulk crystal can be annealed to an equilibrium number, the same as those in a nano-crystal per unit mass. Thus, since battery performance is based on unit mass, you need the name weight of nano-crystals or bulk crystals to get the same capacity (to an order of magnitude, some papers show that surface defects actually INCREASE capacity, nifty stuff).

In addition, Li(z)Ti(x)O(y) is a system that undergoes phase changes during Lithium intercalation and deintercalation (as the battery discharges the "z" goes from 1 to 0). So the crystals are being made a-new with each charge discharge cycle (increasing cycle life, but this is something that also happens in the bulk, no need for nano whatnot).

Interestingly, the energy/power density with lithium titanium oxides is actually lower than that for carbons. A battery with a lithium cobalt oxide cathode and a lithium graphite anode will have a maximum potential of 4.2 V. The battery in question in the article actually sits around 3.0 V.

Finally, the failure mechanism for lithium ion batteries is not the anode, but the area just outside the anode called the SEI layer. This is a passivation layer formed adjacent to the anode by reaction of the neutral lithium with the organic electrolyte. This layer forms initially by irreversibly consuming some lithium, but if the charge/discharge rate is moderate it becomes stable and actually protects the anode. If the charge/discharge is too high, though, the layer breaks and more lithium is consumed to repair it, thus diminishing capacity. After enough of these cycles the batter will dramatically lose capacity.

Thus, the breakthrough in question must deal with a way of maintaining a stronger SEI layer, but it is most definitely at the cost of a lower potential battery.

Charge capacity?

[stanleypane]

Given the current state of battery life, I'm inclined to think this technology might bring along other trade-offs. Current Lithium batteries tend to lose their full charge capacity after using them for a while. If these batteries charge faster and retain more power, what's to stop them from losing that capacity just as quickly?

Personally, I'd be happy not having to replace a battery because it becomes useless after a while. They aren't cheap, and they lose their life too quickly. I guess 2 out of 3 wouldn't be bad, though.

Re:sweet!

[kevinx]

It's those inconsiderate jerks who read the article before they post. Now all of us who posted first can't read it.

Re:Hard hat required

[pong]

My laptop battery has a voltage rating of 10.8. The amount of energy in Joules on a battery with a voltage of 10.8V and power rating of 12Ah, would be

E = 10.8V * 12Ah = 129.6Wh = 467 KJ (3600 J/Wh)

E = P * t, so P = E / t

P = 467 KJ / (5 * 60) secs = 1555W

1555W is less than many hair driers

I think your math is wrong...

[DarkMan]

I don't belive that the claim is that thier new batteries have three times the capacity of a current Li-ion battery. They are claiming three times the power, which I read as meaning that the peak discharge power is three times greater.

This is a lot more reasonable, from my understanding of Li-ion batteries. The theoretical energy capacity isn't three times current batteries, IIRC, so trippling that is unreasonable. But three times the discharge rate is not impossible, and brings them into the range of NiMH batteries, maybe even Lead-Acid. Coupled with the superior energy density of Li-ion, that's very very nice.

This matches well with the claim of faster charging - the limiting factors for charging and dischargeing are related in batteries.

So, your sums become 4Ah in 5 minutes, or a much more reasonable 48 amps. A lot, yes, but not beyond what's currently done with medium current applications.

Reading the press relase as I did above imedialty makes is much more reasonable, although I'd love to get more details. There's a lot hingeing on the word 'power', depending whether you read it in a technical or common definition, so much so that I wouldn't want to depend on it.

3x max current, not capacity

[fhage]

According to http://www.evworld.com/view.cfm?section=communique &newsid=7681 "The nanomaterials Altair is developing are the next generation of electrode materials for lithium-ion batteries and Altair's research and product development is laying the ground work for a new generation of ultra high power lithium ion batteries," commented Dr. K. M. Abraham. "A key requirement to the above applications is the ability to recharge the battery very quickly, for example in a few minutes. Current Li Ion batteries are incapable of such quick charge times because of the chemistry of the anode materials. Altair has found a solution to this with their nano-sized lithium titanium oxide."

Current Li batteries are very limited in their max current. This make them poor choices for high current applications, like electric motors. It won't make your laptop run any longer, but you'll be able to charge it 3x faster.

Re:Seems about due

[fearofcarpet]

This all sounds like BS to me. Our lab is part of a nation-wide program to develop new battery technologies and I have no idea why they claim lattice strain as the main cause for eletrode fatigue... The problem with ANY battery is that ions have to move as the battery is charged/discharged. These ions are all lithium in lithium-ion batteries (AKA lithium rocking chair or rocker batteries). The material between the electrode compartments has to be a insulator able to transport Li+ reliably. Since liquids in batteries are not such a good thing they use various gel mixtures for this medium (and the rate of ion diffusion is inversly related to viscosity). Every charge/discharge cycle more an more ions get stuck and hence lower the capacity of the battery over time.

The "problem" electrode as far as I know is actually the graphite (like the stuff in pencils) end which get's reduced and forms a lithium salt. When you hook up battery the graphite re-oxidizes, sending the electrons through the circuit and Li+ through the insulating medium. Most "nanomaterials" focus on increasing the surface area of this electrode to allow for more efficient (and rapid) charge storage/discharge. At the other electrode is some (probably cystalline) inorganic oxidant which does break down over time. My guess is that they just found some new inorganic electrode material that is slightly better and they, like EVERY other lab, are claiming they've "solved" the Li-ion battery problem. I've seen way too many talks from people claiming essentially the same thing to put my grains of salt away just yet.

But hey, I'm not on the nanobattery (did you barf?) project and am by no means an expert, so someone please correct me if I'm wrong... FYI "nano" makes me want to puke too. Every week there is some jack-ass giving a talk about "nanomaterials" that are MICROns in size and characterized with MICROscopy. In chemistry land (where I live) a nanometer might as well be a mile (except electrons tunnel more frequently) 'cause atoms are really freaking tiny and that's what we've been using to build our materials for over 200 years : )

Is it really 3 times the power?

[grahamsz]

If so then it's only going to allow power to flow out of the battery 3 times faster, allowing a whole new generation of power-hungry athalon laptops (at 1/3rd of the current battery life)

However if it were 3 times the ENERGY then it'd make existing laptops run for 3 times longer.

Re:Snakeoil?

[drinkypoo]

I'll just expect this battery to come with an internal fuse, instead.

Re:Snakeoil?

[tlhIngan]

Current lithium batteries are slow to recharge because they have a high internal resistance, and low tolerance for overvoltage. A typical battery cell with 3.6V idle voltage takes no more than 4.3V when charging, and the .7V drop over the internal resistance allows very little current through the battery, which is why it takes 3hr to recharge fully.

Actually, LiIon has a low internal resistance - it's somewhere between that of NiCd and NiMH chemistries (when new). However, as it ages (i.e., the moment it leaves the factory), the internal resistance gets higher and higher until it can no longer usefully power the load (generally 2-5 years after manufacture).

The reason LiIon is slow to charge is because it requires a complex charge regimen. Plus you can't trickle charge them (destroys them). So you charge them at a constant current up around 90% or so, then switch to constant voltage until the cell stops accepting charge. Then you stop and switch off the charger until it drains to around 95% (estimated), and do a CV charge again.

The end result is you get around 90% charge very quickly, but the last 10% take forever as the charger puts in less and less current.

Charge it incorrectly and they go boom.