New energy storage device could recharge electric vehicles in minutes

Aug 19, 2011 by Lisa Zyga feature
Compared with supercapacitors and batteries, SMCs (with three different electrode thicknesses shown) offer both a high power density and high energy density. Image copyright: Jang, et al. ©2011 American Chemical Society

(PhysOrg.com) -- It has all the appearances of a breakthrough in battery technology, except that it’s not a battery. Researchers at Nanotek Instruments, Inc., and its subsidiary Angstron Materials, Inc., in Dayton, Ohio, have developed a new paradigm for designing energy storage devices that is based on rapidly shuttling large numbers of lithium ions between electrodes with massive graphene surfaces. The energy storage device could prove extremely useful for electric vehicles, where it could reduce the recharge time from hours to less than a minute. Other applications could include renewable energy storage (for example, storing solar and wind energy) and smart grids.

The researchers call the new devices "graphene surface-enabled lithium ion-exchanging cells," or more simply, "surface-mediated cells" (SMCs). Although the devices currently use unoptimized materials and configurations, they can already outperform Li-ion batteries and supercapacitors. The new devices can deliver a power density of 100 kW/kgcell, which is 100 times higher than that of commercial Li-ion batteries and 10 times higher than that of supercapacitors. The higher the power density, the faster the rate of energy transfer (resulting in a faster recharge time). In addition, the new cells can store an of 160 Wh/kgcell, which is comparable to commercial Li-ion batteries and 30 times higher than that of conventional supercapacitors. The greater the energy density, the more energy the device can store for the same volume (resulting in a longer driving range for electric vehicles).

“Given the same device weight, the current SMC and Li-ion battery can provide an electric vehicle (EV) with a comparable driving range,” Bor Z. Jang, co-founder of Nanotek Instruments and Angstron Materials, told PhysOrg.com. “Our SMCs, just like the current Li-ion batteries, can be further improved in terms of energy density [and therefore range]. However, in principle, the SMC can be recharged in minutes (possibly less than one minute), as opposed to hours for Li-ion batteries used in current EVs.”

Jang and his coauthors at Nanotek Instruments and Angstron Materials have published the study on the next-generation devices in a recent issue of Nano Letters. Both companies specialize in nanomaterial commercialization, with Angstron being the world’s largest producer of nano graphene platelets (NGPs).

As the researchers explain in their study, batteries and supercapacitors each have their respective strengths and weaknesses when it comes to energy storage. While Li-ion batteries provide a much higher energy density (120-150 Wh/kgcell) than supercapacitors (5 Wh/kgcell), the batteries deliver a much lower power density (1 kW/kgcell compared to 10 kW/kgcell). Many research groups have made efforts to increase the power density of Li-ion batteries and increase the energy density of supercapacitors, but both areas still have significant challenges. By providing a fundamentally new framework for energy storage devices, the SMCs could enable researchers to bypass these challenges.

“The development of this new class of energy storage devices bridges the performance gap between a Li-ion battery and a supercapacitor,” Jang said. “More significantly, this fundamentally new framework for constructing energy could enable researchers to achieve both the high energy density and high without having to sacrifice one to achieve the other.”

The large surface areas of the SMCs’ electrodes enable rapid shuttling of large numbers of ions between electrodes, resulting in a fast recharge time. Image copyright: Jang, et al. ©2011 American Chemical Society

The key to the SMCs’ performance is a cathode and anode that contain very large graphene surfaces. When fabricating the cell, the researchers put lithium metal (in the form of particles or foil) at the anode. During the first discharge cycle, the lithium is ionized, resulting in a much larger number of lithium ions than in Li-ion batteries. As the is used, the ions migrate through a liquid electrolyte to the cathode, where the ions enter the pores and reach the large graphene surface inside the cathode. During recharging, a massive flux of lithium ions quickly migrates from the cathode to the anode. The electrodes’ large surface areas enable the rapid shuttling of large numbers of ions between electrodes, resulting in their high power and energy densities.

As the researchers explain, the exchange of lithium ions between the porous electrodes’ surfaces (and not in the bulk of the electrode, as in batteries) completely removes the need for the time-consuming process of intercalation. In this process, the lithium ions must be inserted inside the electrodes, which dominates the charging time of batteries.

Although in this study the researchers prepared different types of graphene (oxidized, and reduced single-layer and multilayer) from a variety of different types of graphite, further analysis of the materials and configuration is needed for optimizing the device. For one thing, the researchers plan to further investigate the cells’ cycling lifetime. So far, they found that the devices could retain 95% capacity after 1,000 cycles, and even after 2,000 cycles showed no evidence of dendrite formation. The researchers also plan to investigate the relative roles of different lithium storage mechanisms on the device’s performance.

“We do not anticipate any major hurdle to commercialization of the SMC technology,” Jang said. “Although graphene is currently sold at a premium price, Angstron Materials, Inc., is actively engaged in scaling up the production capacity of graphene. The production costs of graphene are expected to be dramatically reduced within the next 1-3 years.”

Explore further: Study sheds new light on why batteries go bad

More information: Bor Z. Jang, et al. “Graphene Surface-Enabled Lithium-Ion Exchanging Cells: Next-Generation High-Power Energy Storage Devices.” Nano Letters. DOI:10.1021/nl2018492

4.8 /5 (54 votes)

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freethinking
4.1 / 5 (15) Aug 19, 2011
As always I hope this is a real breakthrough and not just hype.
Lightfeet
5 / 5 (5) Aug 19, 2011
Agreed. I hope this is a real breakthrough. I'm not an electrical engineer but it seems to me that there would be a very large electrical current flow during recharging. Will this new technology require special recharging stations?
KaiBrunnenG
3 / 5 (1) Aug 19, 2011
Well this certainly solved the re-charging issue that dogs Li-ion batteries, but I was hoping that they would've been able to double or triple the energy density-which will of course either double the range of EVs.

They probably won't be able to improve the energy density by much since SMCs also use Li-ion. They might need to find another element aside from Lithium to increase it. Using graphene is a step in the right direction though.

I dream of a day when EV batteries can fit in your hand but give you 1,000 km range on a single charge and can replace combustion engines in aircraft (at least the smaller planes).
Nik_2213
5 / 5 (4) Aug 19, 2011
They are going to need a bank of such cells at the recharge station plus some seriously heavy-duty connections to expedite the recharging. IMHO, even if the cable is split to parallel power lines --Like 3-phase but DC-- the connector itself is going to be a major problem. Beyond that, the power density looks so good...
antialias_physorg
4.8 / 5 (9) Aug 19, 2011
I dream of a day when EV batteries can fit in your hand but give you 1,000 km range on a single charge

I wouldn't want that. That would be like an E-hand grenade. If anything went wrong with such a cell (shorting it out or breaking containment) the energy release would cause some major fireworks.

The advantage of the tech in the article is that you can start using your cells one by one (and not in parallel like wioth conventional e-car batteries)
Parallel use causes the weakest cells to have an impact on the lifetime of the entire pack (eventually leading to a neeed to replace the entire pack instead of just the cell that fails)
epsi00
4 / 5 (1) Aug 19, 2011
A revolution in battery technology?
joefarah
1 / 5 (1) Aug 19, 2011
Check out altairnano.com They have Lithium Titanate batteries in vehicles (3rd party vehicles - cars, buses) that can recharge in 10 minutes, with a conservative lifetime of 10 to 20 years. These need special charging stations because you're putting a lot of electrons into those batteries, fast. I think the buses use crossbar charging (on top of the vehicle). Not sure what car chargers are like, but I'm pretty sure the Dutch have tested them and passed them with flying colors. (Altairnano is a Canadian-owned company in California or Nevada I believe.)
TheGhostofOtto1923
4.2 / 5 (5) Aug 19, 2011
I wouldn't want that. That would be like an E-hand grenade. If anything went wrong with such a cell (shorting it out or breaking containment) the energy release would cause some major fireworks.
And yet that is the kind of energy density that flying cars would require.

Do not fear the force.
SteveL
not rated yet Aug 19, 2011
They are going to need a bank of such cells at the recharge station plus some seriously heavy-duty connections to expedite the recharging. IMHO, even if the cable is split to parallel power lines --Like 3-phase but DC-- the connector itself is going to be a major problem. Beyond that, the power density looks so good...
Same thing I was thinking about the cabling and connectors.

Per my conversion utility: 1 gallon of gas = 33.41 kilowatt-hours of electrical energy.
If you wanted to charge the energy equivalent of about 20 gallons of gasoline into a battery in the time period mentioned, you're looking at carrying 668.2 kilowatt-hours - in a minute. I don't know of any connector or cabling that can handle such current without special training and PPE. That's alot of energy.

The only way I can see this work is via a hands-free process with an inductive field under the vehicle and in the charging station pad. But there would be significant losses without standardization.
wealthychef
3.7 / 5 (3) Aug 19, 2011
I'm actually thinking this article is strangely low-key in tone for something that could be a huge breakthrough. Usually there is a big hitch -- what's the problem? These are commercializable, usable and a huge improvement -- too good to be true?
SteveL
5 / 5 (2) Aug 19, 2011
Likely the production of large sheets of graphene in large quantities.
enginarc
4.4 / 5 (9) Aug 19, 2011
While energy storage and mileage seems to be the main problem against widespread use of electric vehicles, IMO we should emphasize the importance of lighter vehicles, research alternate and lighter construction materials and radically change how we perceive transportation.

A 1.5 tonne car (EV or not) carrying a single person or two. It is an immense waste of energy.

We are still trying to save the world without sacrificing from our comfort by simply waiting for the technology to adopt to our selfish needs.
Urgelt
5 / 5 (3) Aug 19, 2011
Well, it sure sounds good. I dare say it'll be some years before we see anything like it in consumer products. I wonder how it performs with respect to heat build-up and dissipation?

Lithium on fire is seriously nasty.

By the way, a "battery" is just a device for storing electricity which uses an anode, a cathode, and a chemical medium for shuttling ions between the two. I'm unconvinced that this design shouldn't be called a battery. Calling it something else sounds like a marketing decision more than an engineering decision.
jalmy
3.7 / 5 (3) Aug 19, 2011
The big advantage of this is clearly the short recharge time. Even if the energy density is equal to li-ion, if it only takes a couple minutes to recharge them. who cares? I wouldnt mind if i had to stop at a gas station every 50 miles if it only took a minute to fill up, and I was getting the equivalent to 1$/gallon of gas. It would be worth my time. The big problem with this battery is that it probly costs 2-3 times the amount of the car.
GSwift7
2.3 / 5 (3) Aug 19, 2011
Yes, cost is going to be the problem. This thing still uses the most costly part of a lithium battery; the lithium. Then it also adds the cost of graphene. Then it has the same performance as a lithium battery except for the charge time. However, since lithium has been around for a while, and that tech is very mature, it's unlikely to improve. Since this is new, there's a lot more likelyhood that they'll find ways to improve it.

As for charging, you just make the connector as safe and robust as you can, then arrange it so that the charge time is at whatever the connector can safely handle. It takes 5 minutes to fill a gas tank. Anything under 7 minutes should be fine for the average consumer.

Oh, think of the government tax carnage if EV's go mainstream. Without fuel taxes, they'll have to find entirely new ways to tax us.
muha
1.8 / 5 (5) Aug 19, 2011
> I dream of a day when EV batteries can fit in your hand but give you 1,000 km range on a single charge and can replace combustion engines in aircraft (at least the smaller planes).

It's impossible I afraid. The batterie energy is a chemical energy like petrol. It means that batterie energy can't be more effective than petrol.
GSwift7
1 / 5 (2) Aug 19, 2011
One other potential gotcha for these is heat. I wonder what kind of heat they generate when charging? Even for a lithium battery, it can get fairly hot, hence the need for fans in EV battery packs.
Sonhouse
not rated yet Aug 19, 2011
I think everyone is underestimating the amount of energy needed for this: say recharging a 25 Kw system in 2 minutes. That would be 25 times 30, needing a 750 Kw charging system. For instance, 750 volts at 1000 amps, 375 volts, 2000 amps. Anyone here got any plans that could make a charge system of that much power?
Burnerjack
5 / 5 (1) Aug 19, 2011
While the charging connection may still be an issue, another issue for the pesent market is "More's law for EV Batteries." IMNSHO, there needs to be a disconnect between the EV purchase and the Batterie purchase. I'd love to own a quality EV with good range and performance but don't want to get stuck with "yesterday's" battery. Battery leasing might be the angle which lights the EV market aflame. Another point is, of course, either battery standardization or universal chargers.
for those inclined towards inductive charging, I wonder what the strong EM field would do to electronics such as pace makers etc.
I'm not down on any of it, just pointing out what I see as impediments to more widespread acceptance.
Eikka
5 / 5 (1) Aug 19, 2011

The only way I can see this work is via a hands-free process with an inductive field under the vehicle and in the charging station pad. But there would be significant losses without standardization.


I wouldn't want to stand anywhere near an induction system that powerful. You're talking about 5-6 megawatts of power being transmitted to the car at a less than 100% efficiency, which means even a 1% loss is 60 kW of stray power to the surroundings.

If your heart doesn't stop due to eddy currents induced in your body, then your wrist watch, your cellphone, and your credits cards would surely suffer a horrible fate.
Nanobanano
3 / 5 (4) Aug 19, 2011
Oh, think of the government tax carnage if EV's go mainstream. Without fuel taxes, they'll have to find entirely new ways to tax us.


The power isn't free, it will come from the electric grid, or from your solar or wind or some other source,like Rossi's E-Cat.

Even if the government taxes electric grids, you'll still save money becaue electric motors are so much more efficient than gasoline ICE motors.
T2Nav
3 / 5 (2) Aug 19, 2011
At this charging rate, they'll have to throw in a few extra lumps of coal down at the power plant to charge this high-tech battery.
MorituriMax
not rated yet Aug 19, 2011
I wouldn't want that. That would be like an E-hand grenade. If anything went wrong with such a cell (shorting it out or breaking containment) the energy release would cause some major fireworks.
And yet that is the kind of energy density that flying cars would require.

Do not fear the force.


For they have cookies!
Sonhouse
not rated yet Aug 19, 2011
Has anyone done the math on the charging station needed for such a fast charge? Suppose the battery holds 25 Kwhr of energy. So if you want to charge it up in one hour, you need to feed it 25,000 watts for one hour to get the battery to peak. Suppose you want to do it in 30 min. Then you have to feed it 50,000 watts for 30 minutes. Ok, now for the big step. Suppose you want to do it in 3 minutes. Now you have to feed the thing 500,000 watts for 3 minutes. Does anyone here have any idea how to cram that much energy into the battery? So 500 volts at 1000 amps for 3 minutes. Or 100 volts at 5000 amps. 50 volts at 10000 amps. Take your pick. One idea might be to have a bank of supercapacitors, a BIG bank, charged up which can discharge all of it in a big rush, but what kind of wiring will it take to deliver 500 volts at 1000 amps? You might end up with a cable the size of a baseball bat and about as flexible. It sounds to me like you have to way up the voltage, 5000 volts at 100 amps.
pokerdice1
not rated yet Aug 20, 2011
Ok so people need to start combing the journals for high volume graphene production techniques. C'mon dammit! Let's start putting things together!!!!!!
PPihkala
not rated yet Aug 20, 2011
I can think of different ways to transfer the charge to your car:
1) You will exchange the whole battery, that is then charged at slower pace at the charging station. This would need standards in batteries to enable swap.

2) You can slowly charge your battery at home or at work or maybe while your car is parked at public parking spot while you are shopping etc. This needs standard charging connectors.

3) You drive your car onto high speed charger that will lift your car into air from bottom and does this in order to have enough contact pressure between it's two copper bars and corresponding contact surfaces at the bottom of the car. Then the charger will raise the charging current while sensing for heat buildup. The less heat, the higher rate it will use. And the charge will come from banks of SMC batteries like in your car. Those charging station batteries are being charged while they wait for the next customer. This will need standard charging rails for your car and in a station.
krwhite
not rated yet Aug 20, 2011
15gWh used annually, if 25% of non commercial vehicles were to drive 10,000 miles a year on a vehicle that did 200 miles to the charge, and took 3 minutes to fill up at 500,000watts. I figured 2.5 hours of total charge time annually from the 50 charges needed to go 10k miles with 12 million cars. Is this right? Says here on wikipedia that the Palo Verde nuclear plant generates almost 30,000GWh annually.. My question would be, would this be feasible for our grid? Also, are my calculations wrong?
krwhite
not rated yet Aug 20, 2011
Above feasibility question meant for the United States grid.
BambiesR
not rated yet Aug 20, 2011
This is a solid breakthrough but application into the real world is the vawncast test of it all. It does seem promising nonetheless.
bg1
5 / 5 (1) Aug 20, 2011
160 wh/kg = 247 btu/lb vs gasoline which is 18000 btu/lb. Still a long way to go in energy per lb.
yoatmon
1 / 5 (1) Aug 20, 2011
In January this year, I'd proposed a design for an USC based on graphene. A sheet of graphene, being two dimensional only, limits the flow of electrons to two directions which is an extreme handicap. Growing MWCNTs, at a length of 20 to 30 nm, onto graphene sheets enables an almost unimaginable surface. The resulting huge CNT-surface is not only a docking area for electrons it also serves to separate the graphene sheets from each other and ensures that the electrical attributes of graphene remain almost unchanged when scaled up to the macro level. Such a graphene-sandwich allows 3-dimensional movement of electrons at an extremely high rate due to the low electrical resistance.
Rudimentary calculations for such a device resulted at ca. 380 wh/g and a power density ca. 150 times higher than that of common Li-ion cells.
I sincerely enjoy the news of this accomplishment as a reality because my predictions months ago have been more or less proven.
StandingBear
not rated yet Aug 20, 2011
By jove, I think we got a power source for the man portable phaser rifle!....or the Go'auld staff weapon.....lol. All kidding aside, the real non sci-fi possibility emerges of a usable laser rifle of great power, especially if two co-axial tunable phased lasers are used in one weapon emitter....the phaser! Retard the phase of one just a quarter wavelength in an X-ray laser, or a laser with an operating wavelength of one iron atom nuclear diameter......or thorium.....or unumpentium....
TheGhostofOtto1923
1 / 5 (1) Aug 20, 2011
By jove, I think we got a power source for the man portable phaser rifle!....or the Go'auld staff weapon.....lol. All kidding aside, the real non sci-fi possibility emerges of a usable laser rifle of great power, especially if two co-axial tunable phased lasers are used in one weapon emitter....the phaser! Retard the phase of one just a quarter wavelength in an X-ray laser, or a laser with an operating wavelength of one iron atom nuclear diameter......or thorium.....or unumpentium....
Indeed. And the commercial air transportation industry is in jeopardy. How will they counter more powerful lasers in terrorist and teenage hands?
PaulRadcliff
5 / 5 (1) Aug 20, 2011
As with most of these articles, promising breakthroughs for 'green' technologies, I reserve hope until these developments reach an electric car, that even I could afford. Mass production and practical efficiency will bring prices down, but we are probably looking at five to ten years before this becomes affordable for the people who need to make their money stretch the farthest. Until Green Cars reach affordability for the poorest working folks, I see no real dent in Big Oil's income or worldwide consumption, which needs to reach half in less than fifty years, to avoid the worst case climate change consequences, as currently predicted. It will be a win, win- if no big oil company buys the patents and buries them, as has been done before with promising battery technology.
Roj
not rated yet Aug 21, 2011
In-Road recharging for electric vehicles already exists in smarter countries.

http://www.physor...386.html
http://www.autowe...10509966

This allows distribution voltages (5-12k volts), and/or high-current cables that handle the required loads.

http://www.physor...735.html
http://www.physor...ard.html
NANOBRAIN
not rated yet Aug 21, 2011
LETS GET RID OF OPEC,WE CAN SAVE BIG MONEY FOR JOBS.
yoatmon
5 / 5 (1) Aug 22, 2011
@ nanobrain
We won't rid of OPEC that fast. We still need oil for many meanful purposes other than burning it and polluting our environment.
bronzecheetah
5 / 5 (2) Aug 22, 2011
160 wh/kg = 247 btu/lb vs gasoline which is 18000 btu/lb. Still a long way to go in energy per lb.


Seriously People. Do the math. Compare apples to apples. Batteries are useless in terms of moving cars --always have been and always will be. Even this so called breakthrough has yet to scratch the surface in terms of energy storage.

Hydrogen.

40 KILO-Watt-Hours/kg. Kilowatt.

Gasoline = 13 kWh/kg
This thing = 0.16kWh/kg

hmmmmm. World changing? I think not.
Eikka
3.7 / 5 (3) Aug 23, 2011

40 KILO-Watt-Hours/kg. Kilowatt.


For your next task, figure out the volume of a kilogram of hydrogen at various pressures and/or phases, and then figure out the weight of the container necessary to keep it there.
SteveL
not rated yet Aug 24, 2011
@krwhite: No, our various national energy infrastructures are not presently designed to support EV recharging in significant numbers.

@GSwift7: The heat generated from charging and discharging traditional lithium batteries is mainly from the resistance of the ions when entering or leaving the anode. There was a company in California a few years ago who was trying to market a new anode design that used nano-technology to control the porosity in the anode. They also demonstrated a 2 minute charge/discharge cycle with no heat. Last I heard they were working on developing terminals that could handle the power. But that's been a few years.

@StandingBear: How about unobtainium?
unknownorgin
1 / 5 (1) Aug 25, 2011
I do not see how this is not a battery or electrochemical process because in the recharge phase the positivly charged Li ions will not move across the porous membrane without negativly charged ions IE O-,Cl- ect moving in in the oposite direction towards the anode in order to establish an electrical current. In a capcitor there is no ion movment and only charge separation takes place.
SteveL
not rated yet Aug 25, 2011
Oh, it's functionally a battery all right. They are just trying to seperate the perception of their product from the idea of an old-style battery and its inherient issues.
antialias_physorg
not rated yet Aug 25, 2011
But if it had been an article on a regular/high-denisty battery design then you'd have argued: "It will never fly because it takes forever to recharge"

Against such circular arguments battery designers just can't win.

Solving one issue at a time - that is how progress is made. This seems like they just solved one of the (major) issues plaguing batteries. Once someone solves the other issue of where to get such a charge in such a short time we're good to go.

Off the top of my head I can think of a few:
- intermittent power storage (think 'gas' stations) which draw power from the grid over long time to store in some other form (e.g. flywheel) which can then delivered high energy densities quickly
- complete exchange of charged packs for empty packs at filling stations
- Better/more intelligent power grids that can communicate with the outlets and can throttel them back when the cumulative load gets to high
- ...