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New ORNL titanium dioxide material shows high-rate capability and long-time cyclability for Li-ion batteries

Meso
Mesoporous TiO2–B microspheres. Click to enlarge.

Researchers at Oak Ridge National Laboratory (ORNL) have designed and synthesized a new titanium dioxide material—Mesoporous TiO2–B microspheres—for high-power lithium-ion batteries. The material combines the advantages of fast lithium transport with a pseudocapacitive mechanism, adequate electrode-electrolyte contact, and compact particle packing in the electrode layer, and shows superior high-rate charge–discharge capability and long-time cyclability for lithium-ion batteries, according to their paper published in the journal Advanced Materials.

The new material allows the battery to be charged to 50% of full capacity in six minutes while the traditional graphite-based lithium-ion battery would be just 10 percent charged at the same current, said Hansan Liu, lead author of the paper. Compared to commercial lithium titanate material, the ORNL compound also boasts a higher capacity—256 vs. 165 mAh g-1—and a sloping discharge voltage that is good for controlling state of charge.

This characteristic combined with the fact oxide materials are extremely safe and long-lasting alternatives to commercial graphite make it well-suited for hybrid electric vehicles and other high-power applications.

The results could also have significance for applications in stationary energy storage systems for solar and wind power, and for smart grids. The titanium dioxide with a bronze polymorph also has the advantage of being potentially inexpensive, according to Liu.

At the heart of the breakthrough is the novel architecture of the mesoporous TiO2-B microspheres, which features channels and pores that allow for unimpeded flow of ions with a capacitor-like mechanism. Consequently, a lithium-ion battery that substitutes TiO2-B for the graphite electrode charges and discharges quickly.

Theoretical studies have uncovered that this pseudocapacitive behavior originates from the unique sites and energetics of lithium absorption and diffusion in TiO2-B structure.

—Liu et al.

Co-author Parans Paranthaman noted that the microsphere shape of the material allows for traditional electrode fabrication and creates compact electrode layers. He also observed, however, that the production process of this material is complex and involves many steps, so more research remains to determine whether it is scalable.

Resources

  • Hansan Liu, Zhonghe Bi, Xiao-Guang Sun, Raymond R. Unocic, M. Parans Paranthaman, Sheng Dai, Gilbert M. Brown (2011) Mesoporous TiO2–B Microspheres with Superior Rate Performance for Lithium Ion Batteries. Advanced Materials. doi: 10.1002/adma.201100599

Comments

HarveyD

Interesting evolution of e-energy storage devices. Improved energy storage density + quicker charge/discharge capabilities + potential lower cost could make near future BEVs more competitive.

Reel$$

Good progress. But we need anodes capable of four times the cycling this material has been tested at. And if manufacturing TiO2-B takes 8-9 steps - the cost will eliminate the benefit.

Some form of synth silicon with lower expansion characteristics or no expansion character might be a direction.

HarveyD

Rell$$...don't you think that many more improved technologies will be around between 2020 and 2030? Progress will not stop. A 400% improvement will come but probably not during the current decade.

kelly

This is a fine breakthrough with huge percentage performance increases, so is seaweed http://www.technologyreview.com/energy/38531/?p1=A2

As GCC readers know, several fine breakthroughs are reported monthly, for many years - perhaps since Sony marketed the first lithium ion battery in 1991 - or earlier.

What's needed is the decades of promised 2X, 5X, or 10X better performance batteries, esp. in EVs, on the market now, before the possibility of a reactionary political party returning us to the hydrogen economy initiative while selling more oil at 2X, 5X, or 10X higher prices.

HarveyD

Naysayers will always maintain that manufacturers with ONLY produce what they have managed to convince us to buy. That could be about anything because the majority believe all those smart ADS. We are no where as smart as we think we are.

Herm

"As GCC readers know, several fine breakthroughs are reported monthly, for many years - perhaps since Sony marketed the first lithium ion battery in 1991 - or earlier."

I think this explosion of reports is fairly recent, lately we get several per month, either reporters have gotten more efficient or there must be a lot of money going into battery research.. and perhaps the really good stuff does not get reported.

JerseyGeoff

Different shades of the same way to solve a problem-- see Altair Nanotechnology's similar solution now several years old and in production.

Treehugger

of all this "breakthrough" reported every month only a tiny fraction will make it through one day one solution will be better overall than others and will be selected, car auto industry doesn't like multiple technologies environment, a jungle of technology is not only unsellable but also not cost effective. Car industry need the battery technology to stabilize around one or 2 robust solutions with 2 or 3 suppliers that crank it by the millions.

Roy_H

I guess I find this more confusing than helpful.

"The new material allows the battery to be charged to 50% of full capacity in six minutes while the traditional graphite-based lithium-ion battery would be just 10 percent charged at the same current, said Hansan Liu"

The only way this makes sense is if the battery has only 20% capacity, in this case a normal Li-ion battery is about 3.7 volts and 20% would only be about 0.8 volts. A battery with this low voltage would be almost useless. I can only conclude that the report is in error, and maybe should read "10 percent charged at the same time duration"

"higher capacity—256 vs. 165 mAh g-1" is definitely a significant improvement but pales in comparison to some other developments reported here. From: http://www.greencarcongress.com/2011/05/chang-20110521.html "The MoS2/G composite with a Mo:C molar ratio of 1:2 exhibited the highest specific capacity of ~1100 mAh/g"

That said, this technology is probably much cheaper than the MoS2/G and probably could be brought to market much sooner.

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