New battery design could help solar and wind power the grid

Apr 24, 2013
SLAC/Stanford's Yi Cui holds a lab demonstration of his group's new lithium-polysulfide flow battery contained in a simple flask. The design could serve as a model for a low-cost, long-life battery that enables solar and wind energy to become major suppliers to the electrical grid. Credit: Matt Beardsley, SLAC National Accelerator Laboratory

(Phys.org) —Researchers from the U.S. Department of Energy's (DOE) SLAC National Accelerator Laboratory and Stanford University have designed a low-cost, long-life battery that could enable solar and wind energy to become major suppliers to the electrical grid.

"For solar and to be used in a significant way, we need a made of economical materials that are easy to scale and still efficient," said Yi Cui, a Stanford associate professor of and a member of the Stanford Institute for Materials and Energy Sciences, a SLAC/Stanford joint institute. "We believe our new battery may be the best yet designed to regulate the natural fluctuations of these ."

Cui and colleagues report their research results, some of the earliest supported by the DOE's new Joint Center for Energy Storage Research battery hub, in the May issue of Energy & Environmental Science.

Currently the electrical grid cannot tolerate large and sudden power fluctuations caused by wide swings in sunlight and wind. As solar and wind's combined contributions to an approach 20 percent, energy storage systems must be available to smooth out the peaks and valleys of this "intermittent" power – storing excess energy and discharging when input drops.

This video is not supported by your browser at this time.
In this video, Stanford graduate student Wesley Zhang demonstrates the new low-cost, long-lived flow battery he helped create. The researchers created this miniature system using simple glassware. Adding a lithium polysulfide solution to the flask immediately produces electricity that lights an LED. A utility version of the new battery would be scaled up to store many megawatt-hours of energy. Credit: SLAC National Accelerator Laboratory

Among the most promising batteries for intermittent grid storage today are "flow" batteries, because it's relatively simple to scale their tanks, pumps and pipes to the sizes needed to handle large capacities of energy. The new flow battery developed by Cui's group has a simplified, less expensive design that presents a potentially viable solution for large-scale production.

Today's flow batteries pump two different liquids through an interaction chamber where dissolved molecules undergo chemical reactions that store or give up energy. The chamber contains a membrane that only allows ions not involved in reactions to pass between the liquids while keeping the active ions physically separated. This battery design has two major drawbacks: the high cost of liquids containing rare materials such as vanadium – especially in the huge quantities needed for grid storage – and the membrane, which is also very expensive and requires frequent maintenance.

These diagrams compare Stanford/SLAC's new lithium-polysulfide flow battery design with conventional "redox" flow batteries. The new flow battery uses only one tank and pump and uses a simple coating instead of an expensive membrane to separate the anode and cathode. Credit: Greg Stewart, SLAC National Accelerator Laboratory

The new Stanford/SLAC uses only one stream of molecules and does not need a membrane at all. Its molecules mostly consist of the relatively inexpensive elements lithium and sulfur, which interact with a piece of lithium metal coated with a barrier that permits electrons to pass without degrading the metal. When discharging, the molecules, called lithium polysulfides, absorb lithium ions; when charging, they lose them back into the liquid. The entire molecular stream is dissolved in an organic solvent, which doesn't have the corrosion issues of water-based flow batteries.

"In initial lab tests, the new battery also retained excellent energy-storage performance through more than 2,000 charges and discharges, equivalent to more than 5.5 years of daily cycles," Cui said.

To demonstrate their concept, the researchers created a miniature system using simple glassware. Adding a lithium polysulfide solution to the flask immediately produces electricity that lights an LED. (see video)

A utility version of the new battery would be scaled up to store many megawatt-hours of .

In the future, Cui's group plans to make a laboratory-scale system to optimize its process and identify potential engineering issues, and to start discussions with potential hosts for a full-scale field-demonstration unit.

Explore further: Fukushima accident underscores need for US to seek out new information about nuclear plant hazards

More information: Yuan Yang, Guangyuan Zheng and Yi Cui, Energy Environ. Sci., 2013 DOI:10.1039/C3EE00072A , http://pubs.rsc.org/en/content/articlelanding/2013/EE/C3EE00072A

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User comments : 13

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topkill
1 / 5 (1) Apr 24, 2013
Is this a new and different update to his last announcement? I believe they were doing pretty much the same thing last time we talked and claiming 40,000 cycles?
Feldagast
1 / 5 (1) Apr 24, 2013
Wonder how toxic they are.
sequence
not rated yet Apr 24, 2013
New batteries can power anything.
Embrace OpenID. PhysOrg ranks highly enough on Google News to warrant it.
italba
1 / 5 (2) Apr 24, 2013
Wonder how toxic they are.

Usually light elements (lithium 3, sulphur 16) are the least toxic. You can drink oil or breath methane, if you prefer.
Telekinetic
1 / 5 (4) Apr 24, 2013
Dr.Frankenstein used a similar apparatus to the one in the photo- you know what bolts of lightning hitting a kite could do to his castle's electrical grid.
FMA
not rated yet Apr 25, 2013
A lemon and a potato can light a LED too!!

There is not much about the technical thing on the battery.
antialias_physorg
5 / 5 (1) Apr 25, 2013
Wonder how toxic they are.

The metal itself is highly corrosive (so better not touch) and flammable. If it comes into contact with water it emits hydrogen and a caustic agent (so better not breathe).
Lithium is found in the body of any organisms. However, it doesn't seem to serve any function (you can survive fine without it).

Taking some simple precautions it's relatively harmless and simple to handle in technical systems. The ecological dangers of such a system leaking (soil contamination, groundwater contamination) aren't as severe as one might think.
betterexists
1 / 5 (5) Apr 25, 2013
1/Every..including infants... 5000 in U.S is a New Graduate Student from abroad for this new year.
313,000/62.058 =
http://www.silico...dy-says/

http://www.usnews...n-people
gimpypoet
1 / 5 (1) Apr 25, 2013
Most of the wind/solar systems I have seen charge battery banks and use an inverter to produce ac current. most do not dump energy directly to the grid, so where are the so-called peaks and valleys coming from anyhow? We need to be using all the tech now and stop waiting for better tech. who could afford to wait for new more efficient devices? they could be incorporated when invented. Just like cars that are produced every year with better features, the old ones are still being driven daily.
antialias_physorg
5 / 5 (2) Apr 25, 2013
A lemon and a potato can light a LED too!!

Lemons and potatoes don't scale well. (Also they're not easy to recharge quickly)
GraemeMcRae
not rated yet Apr 26, 2013
Wonder how toxic they are.

Usually light elements (lithium 3, sulphur 16) are the least toxic. You can drink oil or breath methane, if you prefer.

Pass me a steaming cup of HCN, please!
italba
1 / 5 (2) Apr 26, 2013
Wouldn't you prefer some Plutonium?
Howhot
not rated yet Apr 30, 2013
Game changer!