From the OHIO STATE UNIVERSITY
New design brings world’s first solar battery to performance milestone
Sunlight makes the new ‘aqueous solar flow’ battery 20 percent more efficient than today’s lithium-iodine batteries
COLUMBUS, Ohio–After debuting the world’s first solar air battery last fall, researchers at The Ohio State University have now reached a new milestone.
In the Journal of the American Chemical Society, they report that their patent-pending design–which combines a solar cell and a battery into a single device–now achieves a 20 percent energy savings over traditional lithium-iodine batteries.
The 20 percent comes from sunlight, which is captured by a unique solar panel on top of the battery, explained Yiying Wu, professor of chemistry and biochemistry at Ohio State.
The solar panel is now a solid sheet, rather than a mesh as in the previous design. Another key difference comes from the use of a water-based electrolyte inside the battery.
Because water circulates inside it, the new design belongs to an emerging class of batteries called aqueous flow batteries.
“The truly important innovation here is that we’ve successfully demonstrated aqueous flow inside our solar battery,” Wu said.
As such, it is the first aqueous flow battery with solar capability. Or, as Wu and his team have dubbed it, the first “aqueous solar flow battery.”
“It’s also totally compatible with current battery technology, very easy to integrate with existing technology, environmentally friendly and easy to maintain,” he added.
Researchers around the world are working to develop aqueous flow batteries because they could theoretically provide affordable power grid-level energy storage someday.
The solar flow battery could thus bridge a gap between today’s energy grid and sources of renewable energy.
“This solar flow battery design can potentially be applied for grid-scale solar energy conversion and storage, as well as producing ‘electrolyte fuels’ that might be used to power future electric vehicles,” said Mingzhe Yu, lead author of the paper and a doctoral student at Ohio State.
Previously, Yu designed the solar panel out of titanium mesh, so that air could pass through to the battery. But the new aqueous flow battery doesn’t need air to function, so the solar panel is now a solid sheet.
The solar panel is called a dye-sensitized solar cell, because the researchers use a red dye to tune the wavelength of light it captures and converts to electrons. Those electrons then supplement the voltage stored in the lithium-anode portion of the solar battery.
Something has to carry electrons from the solar cell into the battery, however, and that’s where the electrolyte comes in. A liquid electrolyte is typically part salt, part solvent; previously, the researchers used the salt lithium perchlorate mixed with the organic solvent dimethyl sulfoxide. Now they are using lithium iodide as the salt, and water as the solvent. (Water is an inorganic solvent, and an eco-friendly one. And lithium iodide offers a high-energy storage capacity with low cost.)
In tests, the researchers compared the solar flow battery’s performance to that of a typical lithium-iodine battery. They charged and discharged the batteries 25 times. Each time, both batteries discharged around 3.3 volts.
The difference was that the solar flow battery could produce the same output with less charging. The typical battery had to be charged to 3.6 volts to discharge 3.3 volts. The solar flow battery was charged to only 2.9 volts, because the solar panel made up the difference. That’s an energy savings of nearly 20 percent.
The project is still ongoing, and the solar flow design will undoubtedly evolve again as the researchers try to make the battery more efficient.
Doctoral student and study co-author Billy McCulloch said that there are many different directions the research could take.
“We hope to motivate the research community to further develop this technology into a practical renewable energy solution,” he added.
The team’s ultimate goal is to boost the solar cell’s contribution to the battery past its current 20 percent–maybe even to 100 percent.
“That’s our next step,” Wu said, “to really achieve a fully solar-chargeable battery.”
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Aqueous Lithium-Iodine Solar Flow Battery for the Simultaneous Conversion and Storage of Solar Energy.
Abstract
Integrating both photoelectric-conversion and energy-storage functions into one device allows for the more efficient solar energy usage. Here we demonstrate the concept of an aqueous lithium-iodine (Li-I) solar flow battery (SFB) by incorporation of a built-in dye-sensitized TiO2 photoelectrode in a Li-I redox flow battery via linkage of an I3(-)/I(-) based catholyte, for the simultaneous conversion and storage of solar energy. During the photoassisted charging process, I(-) ions are photoelectrochemically oxidized to I3(-), harvesting solar energy and storing it as chemical energy. The Li-I SFB can be charged at a voltage of 2.90 V under 1 sun AM 1.5 illumination, which is lower than its discharging voltage of 3.30 V. The charging voltage reduction translates to energy savings of close to 20% compared to conventional Li-I batteries. This concept also serves as a guiding design that can be extended to other metal-redox flow battery systems.
Title – Might that be “milestone?”
Interesting technology
I like the idea of measuring energy in volts. It’s like measuring IQ in pounds. I’m a genius!
It’s actually common in the battery business. The amount of energy stored in a battery is difficult to determine but is related to the voltage level. It’s how your phone knows when it’s fully charged or at 50% level, etc. It only works when using the same battery type.
It’s more a rule of thumb. The energy level is also determined temperature of the battery and the load.
“Around”? Is that some new SI measurement I missed. I mean, when it comes to GAT (whatever that is) it gets quoted to two decimal places.
Maybe it’s code for the open circuit terminal voltage when fully charged.
When I saw that they felt the need to explain water and declare it eco-friendly, I was bemused. But then I was reassured.
In a world where CO2 has been redefined into a pollutant and occasional ‘toxin’, I am relieved to see that water is still on the side of right, justice and the American way.
Water in its vapour phase is a greenhouse gas and will have to be the next target once we have rid the world of the scourge of carbon dioxide!
“… I am relieved to see that water is still on the side of right, justice and the American way.”
They forgot to add the word “yet”. Water is not a pollutant…yet.
Give them time, they are making it up as they go.
Brilliant! We’ve been attacking water pollution all wrong. Instead of getting rid of the pollution, we just need to get rid of the water. Problem solved..
If we refer to wet cell phones as ‘water polluted’ it will put a negative spin into action and change the public perception to H2O negativity.
Let’s ban dihydrogen monoxide…anyone want to sign a petition? I got like 100% of the guys at EPA HQ to sign…it that a problem?
oh yeah /sarc
They’ve built a battery with a built in solar panel. And this is supposed to be impressive?
Actually I have had several of those for years. Out put is 8,000 volts. Intermittently. 😉
http://www.zarebasystems.com/store/electric-fence-chargers/esp30m-rs
In anticipation of automotive utility, I’ve removed my hood and relocated the battery compartment to the center of the engine block. I’ve also asked the apartment manager to remove the carport roof.
When someone comes up with a way to recycle lithium cheaper than mining it, these MAY be more “eco-friendly” than lead acid. Until then, they are unsustainable polluting ‘piles’ o’ poo. That pun should rate a moderation!
“New design brings world’s first solar battery to performance milestone”
Big deal. Tom Swift Jr. had better solar batteries in 1955 and he charged them in outer space!
http://www.amazon.com/Tom-Swift-His-Outpost-Space/dp/B0006AURH0
I might build one of these myself. Where do I buy a sheet of titanium? Home Depot or Canadian Tire?
McMaster-Carr. They carry Grade 2 and Grade 5.
This reminds me of the claim that sugar would make more energy dense batteries.
http://www.vtnews.vt.edu/articles/2014/01/012213-cals-battery.html
No news on that lately?
How long can it store and what is the depreciation? How temperature sensitive is it.?
Eugene….yes…the world is that stupid. I read the article, then re-read 4 times….then had a beer and re-read again. It falls right in line with the 97% consensus BS. Con artists is to nice a term for these charlatans.
I don’t think that energy conversion efficiency (amp. hours in vs. amp. hrs out) has been the technical bottleneck for electric vehicles or home storage of intermitent electricity. The 100 year old problems are still energy density (volume and weight), usefull discharge cycles, cost and material hazards. This does not represent a breakthrough of any kind.
Let me know when they have something 5 or 10 times more efficient. THAT would be news.
I mean, is this it? Someone ekes out another 20 percent and it is big news?
If it is a combined solarcell and battery it is ok, if it is also cost effective. Only problem is i can’t find out what it is.
In his excellent review of intermittent energy storage Ruud Istvan showed that, with current and foreseeable technology, the required storage for intermittent sources such as wind and solar, will cost 10-100 times the cost of the (already expensive) renewable generation:
http://judithcurry.com/2015/07/01/intermittent-grid-storage/
This means that a 20% gain in storage performance / efficiency is too small a step forward, even if real, to make a difference.
While it might allow the academics to elbow past their peers into the media spotlight, it won’t make intermittent storage a reality.
Menicholas August 1, 2015 at 9:32 am
Thanks, Menicholas. Let me make a more substantive comment to you. Their claim is that their battery is “20% more efficient”. Where do they get the extra “efficiency”? The article says:
and
Now, the improvement is (3.6 – 2.9) / 2.9 = 0.6 / 29 = 24%, so their calculation is correct … but what does that calculation actually mean?
The problem is, the difference is just the solar cell. Let’s replace the solar cell with a tiny fossil fuel generator that puts out 0.6 volts to a 2.9 volt battery … does that make the battery 24% “more efficient”?
Of course not. If that were the case, we could make a battery 1000% more “efficient” just by increasing the size of the generator.
So that is why I would say that this is garbage. Not because of a “knee-jerk and reflexive dislike”, but because the idea that you can increase the efficiency of a battery by attaching a generator or a solar cell to it is a scientific joke.
Regards,
w.
Now, the improvement is (3.6 – 2.9) / 2.9 = 0.6 / 29 = 24%, so their calculation is correct … but what does that calculation actually mean?
It’s total nonsense, utterly meaningless. It seems to me that a ‘media’ person has written the press release and comprehensively corrupted everything the researchers told him/her and failed to explain anything at all about the invention.
This would seem to be an everyday occurrence with university press releases; written by people without the ability to understand what they are, sadly, mis-communicating.
Doesn’t 3.6 – 2.9 = 0.7 rather than 0.6?
Dang … if I could type, I’d be dangerous … I did the calculation correctly (+24%), but then I wrote it down on the page wrong.
Good catch,
w.
They should have left out the battery.
Then on the other hand…
“Heavier than air flying machines are impossible.”
— Lord Kelvin
“Flight by machines heavier than air is impractical and insignificant, if
not utterly impossible.”
— Simon Newcomb, Director, U.S. Naval Observatory, 1902
“Aerial flight is one of that class of problems with which man will never
be able to cope.”
— Simon Newcomb, 1903
“The resistance of air increases as the square of the speed and works as
the cube [of speed]…. It is clear that with our present devices there
is no hope of aircraft competing for racing speed with either our
locomotives or automobiles.”
— William H. Pickering, Director, Harvard College Observatory, 1910
“The popular mind often pictures gigantic flying machines speeding across
the Atlantic carrying innumerable passengers in a way analogous to our
modern steam ships. . . it seems safe to say that such ideas are wholly
visionary and even if the machine could get across with one or two
passengers the expense would be prohibitive to any but the capitalist who
could use his own yacht.”
— William Henry Pickering, Astronomer, 1910
Bon Appétit
michael
To my mind, there is a massive flaw in this claim. Let’s start with the basic priciples:
– a power source is used to charge a storage device.
– the storage device is then used as a source of power.
– the storage device’s efficiency is the power output/input ratio. (There are other measures of its utility, this is a principal one).
In this item, the claim is that putting a solar panel on the storage device makes it more efficient, because then it doesn’t need to have as much power charged into it in the first place.
But that’s nonsense, because the solar panel isn’t a storage device or part of a storage device – it’s part of the charging process. The efficiency of the storage is unaffected by the solar panel.
Apologies, Willis, I missed that you had said this already – http://wattsupwiththat.com/2015/08/01/claim-of-new-efficiency-milstone-in-a-new-solar-batter/#comment-1998818
http://www.ambri.com/
These people are talking about a 2MW battery. Liquid metal.
Lithium Titanate is a great step forward and you van buy it now: 20.000 charging cycles compared to 1500 cycles for Lition ion and it’s brothers and sisters, almost no thermal issues (safe) 98% efficiency, high charge en discharge loads and an operational temperature range from -40 to + 60+ degrees Celsius.
http://www.ev-power.eu/LTO-Cells/
If I lived in a sunny environment I would think about combining these batteries with the Desert PV Module that comes with an operational temp. up to 125 degrees, a life cycle of 75 years + without PID (Potential Induced Degradation) wich lowers the yield of conventional solar modules over time and live off grid. Hell, I even would consider driving an electric car with those batteries.
http://www.jvg-thoma.de/de/photovoltaik/desert-technologie/
I think Elon Musk is producing the wrong type of battery.
Bill Gates Provides Boost To Renewable Energy Storage Company Aquion Energy
April 3rd, 2013 by Nicholas Brown
Bill Gates, the well known co-founder of Microsoft, has decided to provide a financial boost to renewable energy storage research and development (R&D). He is one member of a group of high-profile investors who are investing $35 million into Aquion Energy.
The company is creating a water-based battery system intended to be cheap and environmentally friendly. Aquion’s energy storage technology is reportedly being developed for large- and small-scale energy storage projects, and the company is delivering pre-production energy storage units throughout this year, with the intention to ramp up production at a high-volume manufacturing plant in Pennsylvania by the end of 2013.
“Aquion Energy is fundamentally changing the economics of power generation, transmission and distribution by delivering cost-effective energy storage systems that are made from abundant, nontoxic materials as simple as saltwater,” the company’s website states. “Aquion’s novel Aqueous Hybrid Ion (AHI) battery technology is optimized for stationary energy storage applications including off-grid and micro-grid systems, commercial and industrial energy storage, and grid scale applications.”
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It’s always Bill Gates. Are you all going to start buying pills from him too?
I always thought batteries dicharged amp-hours not volts. Then again electrical theory must be subject to computer models now.
I priced out some deep cycle golf cart flooded 6 Volt batteries at the COSCO in Caguas, Puerto Rico recently. Each battery cost $83 plus tax. In my application I needed 6 of this heavy puppies. Then went to West Marine in San Juan and inquired about Gel Cell batteries for the same configuration. They priced out at about $400 each all taxes included. The wet cell require maintaining charge more often, and give off gas when being charged. Eventually equalization charging will be required. The Gel cells can be left in fully charged states for months at a time and never need topping up with distilled water as do the flooded batteries. The flooded batteries are subject to leakage of acidic water, the Gel are sealed and should not leak or outgas. Equalization is not required for Gel cells. In my application the individual units are located in difficult to get to places so infrequent access is a factor and in a very closed and tight environment where gas and acid are decidedly not welcome.
Ten years ago, I think I remember paying about $175 for the equivalent Gel cell battery.
Recently I have been pondering a solar / battery set up for a farm application specifically a well.
It seems battery technology has a long way to go for my needs. Perhaps the Tesla factory in Reno will be of some help in the future.
I await progress.