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Sulfur Polymers Could Enable Long-Lasting, High-Capacity Batteries
MTorrice writes "Lithium-sulfur batteries promise to store four to five times as much energy as today's best lithium-ion batteries. But their short lifetimes have stood in the way of their commercialization. Now researchers demonstrate that a sulfur-based polymer could be the solution for lightweight, inexpensive batteries that store large amounts of energy. Battery electrodes made from the material have one of the highest energy-storage capacities ever reported"
Litihium Ion batteries should maintain capacity for about 1000 cycles, whereas Lithium-sulfur batteries traditionally went kaput after about 100. But it looks like they are getting pretty close to something feasible, from the article: "The best performing copolymer consisted of 90% sulfur by mass. Batteries using this copolymer had an initial storage capacity of 1,225 mAh per gram of material. After 100 charge-discharge cycles, the capacity dropped to 1,005 mAh/g, and after 500 cycles it fell to about 635 mAh/g. In comparison, a lithium-ion battery typically starts out with a storage capacity of 200 mAh/g but maintains it for the life of the battery, Pyun says."
I saw an interesting graph in Aviation Week some time ago about the energy density of batteries versus the same mass of hydrocarbon fuel. The article was in relation to the idea of creating (plug-in) hybrid airliners.
The batteries used in the 787 store four orders of magnitude less energy than the equivalent mass of jet fuel.
I'm mentioning this because it looks like these batteries would bring the difference up to three orders of magnitude.
Still a ways to go before batteries can compete against hydrocarbon/fossil fuels.
myke
Mimetics Inc. Twitter
There have been a lot of materials developments in battery designs over the last year or two. Some of them are providing 10x or better power storage with varying lifetimes. I'm really looking forward to seeing some of this make it into production. It would be better if they could couple improved batteries with some minimalist portable computer designs. People comfortable with Unix would get by with something with much lower specks than is typical today (assuming a minimalist interface), and the battery could probably last for hundreds of hours. I wouldn't mind that a bit.
Some of the other battery tech could be very useful for emergency situations.
This might be one to keep an eye on: A Battery That Runs On Sugar Could Soon Be Powering Your Electronics
much of left-wing thought is a kind of playing with fire by people who don't even know that fire is hot - George Orwell
FTA: 'The best performing copolymer consisted of 90% sulfur by mass. Batteries using this copolymer had an initial storage capacity of 1,225 mAh per gram of material. After 100 charge-discharge cycles, the capacity dropped to 1,005 mAh/g, and after 500 cycles it fell to about 635 mAh/g. In comparison, a lithium-ion battery typically starts out with a storage capacity of 200 mAh/g but maintains it for the life of the battery, Pyun says.' So, situations in which a massive blast of current is required could benefit quite well from these batteries. I'm thinking like sitting at light on Mulholland and turning a knob on the Tesla's dashboard that is graduated in 1960's TV Batman style: Low-Medium-High-Zowie!
I deny that I have not avoided attaining the opposite of that which I do not want.
How fast can it discharge?
The voltage of a lithium-sulfur battery varies between 1.7 and 2.5 volts. Without knowing the voltage you don't know how much energy the batteries can actually store.
So, for example, the energy density after 500 charge-discharge cycles is about 4.5 MJ/kg. That's enormous for a battery -- about 10% of the energy density of gasoline.
where's my flying car?
First off that's a bald-faced lie: Energy density of:
Gasoline: ~46 MJ/kg
Lithium-ion battery: 0.36-0.875 MJ/kg (1/127 - 1/52 times gasoline)
Lead-acid battery: 0.17 MJ/kg (1/270 times gasoline)
So even lead acid batteries are only two orders of magnitude less energy dense than gasoline.
As for the suitability in vehicles - that depends entirely on the application. For aircraft the energy density per both unit mass and unit volume is very important, so I doubt we'll see electric jetliners any time soon. For automobiles and other short-range land vehicles on the other hand batteries are already adequate for a lot of applications, and cost is the primary limiting factor. A measly 5x increase in capacity could extend the range of the 85kWh Tesla Model S from 265 miles to 1325 miles - still not enough for a long road trip on a single charge, but a lot further than most people care to drive in a single day, and overnight charging in hotel parking lots could be extremely convenient.
And for stationary applications the energy density per dollar is the only particularly important metric, and other battery technologies are probably more applicable to such applications.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
1) are these expensive to make?
2) can they be scaled up to be used as batteries in an electric car?
3) where are my keys?
Anons need not reply. Questions end with a question mark.
This is probably the most coverage I've ever seen for an article in ACS Macro Letters...
Some kind of modular system where a standarized batterypack is used which can be refurbisched with material (sulfur) reused?
Smells fishy to me.
Sulphur Batteries?!!!? The exhaust is gonna smell like rotten eggs!
You stereotypers are all the same...
... they're taking out of gasoline for them.
Well, if Moore got his own law, I'm going to go ahead and call it erroneus's law. "batteries will get better."
I made it more simple and easier not to fail in the future too. So is it me or are they creating batteries out of just about everything?
Airliner turbines are extremely efficient at transforming energy into air movement. Because of expanding gasses in the burn process inside the turbine, roughly 9 times the amount of air being used in the burn process is being "propelled" on the outside of the engine. The mix of these at the back of the engine is also very carefully engineered. This results in an extremely efficient transformation, compared to a combustion engine as used in cars.
Getting the same amount of efficiency from an electrically driven turbine will be a challenge. Getting the same or better amount of efficiency from the system, including the primary generation of electricity, transporting it, battery losses and converting it in the electrical turbine doesn't sound very feasible at all. It's systems that matter, not components, right?
I was promised a flying car. Where is my flying car?
We need devices that consume less power and batteries that last longer (retain the same charge across multiple cycles).
Any other formula will lead to devices that waste power and burn through batteries with increasing speed. I'm not looking forward to garbage lots filled to the sky with used batteries.
What matters, in the end, is the amount of energy a battery can store.
With Lithium Sulfur cells, the voltage is a little more than half as high as for Lithium Ion batteries, so the initial advantage is not as large as it might seem from the mAh numbers.
HI O WISE PRINCE. WHT TOOK U SO DAM LONG?
Batteries using this copolymer had an initial storage capacity of 1,225 mAh per gram of material.
At what voltage? mA*h isn't a unit of energy. V*mA*h is.
Article says "In comparison, a lithium-ion battery typically starts out with a storage capacity of 200 mAh/g but maintains it for the life of the battery, Pyun says."
Hmm. I have lithium ion batteries that can't hold a charge at all.
And it's only partially to do with how they're used. Lithium ion batteries lose capacity while in storage. Which is why you should never buy a used, or a new-old-stock one.
They'll have to use some pretty strong casing on these things if they want to use them in cars because if they leaked in a crash things could get really nasty as free sulphur burns quite easily and creates SO2 which would kill or severely cripple anyone trapped nearby quite quickly.
The total amount of energy stored is much larger per cycle - about five times as much. So 200 recharges for a LiS battery would give as much play time on your phone as 1,000 recharges on a Li-ion battery (the typical lifetime of such a battery). With the loss of capacity that may be 250 recharges for the LiS battery, with it still going strong after all that time.
So what're they waiting for? Life time is more than good enough already! I want one of these batteries! Much better than having to recharge my phone every single day!
now, lets take a light plane for which I can find enough info to do this with, the jabiru j160D ok. so the fuel in it weighs (135L * 0.72kg/L) = 97.2kg. Now, the engine in it, the Jabiru 2200cc Aircraft Engine, weighs 62.8kg, and has a max power output of 60kw, and cruises at 75% power, so lets assume 50kw cruise power to account for takeoff and landing. So in total, engine and fuel weight 97.2 + 62.8 = 160kg
so lets rip that 160kg out and replace it with a EMRAX228 Brushless AC electric Motor with a 100kw power output and weighing in at 11.9kg, leaving us 148.1 kg worth of batteries, with a energy storage capacity of 148.1 * 0.66 = 97.746 kwh. so, at the cruise speed of 100knots = 185.2km/h, your looking at a range of (97.746kwh / 50kw) * 185.2km/h = 362km in about 2 hours.
The gasoline version can fly at the same speed for 8.5 hours. So, sure, the range is a quarter of the gasoline one, but you could ditch a passenger, chuck another 100kg of batteries in there and get that up to about 3.5 hours and 630km of range. Pretty damn good for a few dollars of electricity, negligible maintainence costs on a electric engine vs gasoline engine. sure as hell beats the $100+ youll pay for fuel alone for that same 3.5 hour trip.
I wonder if people are working on charged liquid electrolytes based batteries. If I could drain the electrolyte from the discharged battery, refill it will charged electrolyte much like filling gasoline into a tank. Must be a dumb idea because I have not seen any excited posts about it. May be the energy density is so very poor for these charged electrolytes.
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
So that makes it about 6% the energy density.
But planes can do their own mid-air refuelling.
It should be possible to group 2 for these together with an advertised capacity of ~1200mAh and then add some smart discharge circuitry to keep the total capacity at ~1200mAh. e.g as the first cell nears half capacity, take it off-line and put a fresh one on-line; after that one degrades (you've already gone 1000 cycles now) put the two "half capacity" cells on-line and run them into the ground (maybe get another 500 cycles). You'd need 6 standard Lion cells to get the same capacity; so still a 3x improvement. More cells and more smarts would smooth-out the capacity curve over time; electric cars already have sophisticated battery management systems.
Just to play devil's advocate...
What are the C ratings when charging and discharging. I have Lithium Polymer batteries for RC planes that are capable of a 1C charge rate and a 30C discharge rate. That means it charges fairly slowly but it can release power quickly to handle the high amp draw of some electric motors. It doesn't matter how dense the battery is if it cannot discharge at a rate sufficient to power the device or it takes too long to charge.
Also, how stable/safe are these batteries? Some types of Lithium batteries do not handle damage very well... in other words, they catch fire and burn until their internal fuel is exhausted. If energy storage is dense and it doesn't handle damage well, then that may limit their use.
Finally, how easily can they be recycled and how safe is their disposal? If they don't support as many charge cycles, then they will need to be replaced at some point. I would personally prefer we don't have something that is highly toxic going into our landfills or something that is expensive to dispose of.
These batteries may be great... but they may not be... I guess will find out when when companies decide to use or ignore this tech.
"Batteries using this copolymer had an initial storage capacity of 1,225 mAh per gram of material. After 100 charge-discharge cycles, the capacity dropped to 1,005 mAh/g, and after 500 cycles it fell to about 635 mAh/g. In comparison, a lithium-ion battery typically starts out with a storage capacity of 200 mAh/g but maintains it for the life of the battery, Pyun says."
So, the lithium sulfur battery, after a mere half as many cycles as a lithium ion battery can substain, only has THREE TIMES the charge of a new lithium battery. At what point does it fall to less than a lithium ion battery at the same number of cycles?
Regardless, I think I could live with a battery that holds from 3 to 6 times as much charge as the typical lithium ion battery, even if it only lasted half as long.
http://benthamscience.com/open/tomsj/articles/V005/SI0203TOMSJ/215TOMSJ.pdf
Telsa and others have shown the interesting kind of electric vehicles you can build. Batteries still limit cost and distance. Another factor of 2-5 performance cost will clinch it.
It doesn't even need to be that revolutionary in its deliverable form to be a game changer. Even a doubling would be huge. Ive looked at the nissan leaf (roughly 100 miles on a charge) and the chevy volt (35 on electric, then gas) but haven't bought (yet).
If I could get a leaf that went 200 miles on a charge, or a volt that went 80 miles on a charge and gasoline after that, I would be in the showroom tomorrow.
Technically we could easily make a high powered battery pack using Lithium Polymer batteries due to their high energy densities. The downside of course is your car turns into a bomb if the battery pack malfunctions or is punctured. I wonder if these high density Sulphur batteries are as stable as some of the Lithium Phosphate Manganese batteries that are used in modern electric cars? Otherwise we'll never see them in large applications because they would be considered to be unsafe.
I couldn't find pricing for new vehicles or kits on their site, but their for sale page included both factory refurb and used planes from others which puts a decent 2-4 seater plane at under 120k. They even had their old model 2 seaters with 0 hour refurb engines going for around 60 grand.
Point being, while not CHEAP, those are comparably prices to 'mid-range' luxury cars, and certainly not out of the budget for anyone who could afford a house or nice car. Assuming you can cover the maintenance fees for the amount of hours you'd be flying in it years you might even be able to locate yourself somewhere that would be uncommutable by car but offer you the benefits of both low cost living (be it property or supplies) and high income work (say for example a 2 hour commute to silicon valley from somewhere much cheaper to live, likely in the valley somewhere (Weather permitting of course!)
The Lithium-sulfur batteries are less longer lasting than Li-Ion, because their performance degrades faster over time. It doesn't matter that after so many cycles the battery still performs better than Li-Ion, it degrades faster and will eventually drop below Li-Ion after a large enough number of cycles.
This will lead product designers to equip their products with smaller, lighter-weight, cheaper, less-longer-lasting batteries with the same initial energy capacity as a heavier Li-Ion.
even with just a 100 charges a battery that has 1.2 A per gram sounds awesome for RC flying.
www.hardwar.org - A remake of the old classic Hardwar
"Recently we found ourselves with an odour problem beyond our worst expectations. During early experiments, a stopper jumped from a bottle of residues, and, although replaced at once, resulted in an immediate complaint of nausea and sickness from colleagues working in a building two hundred yards away. Two of our chemists who had done no more than investigate the cracking of minute amounts of trithioacetone found themselves the object of hostile stares in a restaurant and suffered the humiliation of having a waitress spray the area around them with a deodorant."
http://pipeline.corante.com/archives/2009/06/11/things_i_wont_work_with_thioacetone.php
Stop worrying about the risks of nuclear power and start worrying about the risks of not using nuclear power.