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."

Comments

Still a ways to go

[mykepredko]

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

Re:Still a ways to go

[Anonymous Coward]

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

Based on a back-of-the-envelope calculation, that number seems wrong. Could you have misread Aviation Week?

Jet fuel has an energy density close to 45 MJ/kg. A lithium-ion battery has an energy density of (approximately) 150 Wh/kg, which is 540 KJ/kg. That's about 1.2% of the energy density of the jet fuel, which is more like 2 orders of magnitude, not 4.

4 orders of magnitude below jet fuel is more in the range of supercapacitors than batteries.

Re:Still a ways to go

[Gravis Zero]

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 problem with that comparison is that it considers that the engines and motors will have the same efficiency which is not true at all. hypothetically, if your motor is four times as efficient as an engine but your battery has only half the energy storage of the engine's fuel, the motor is still going to run twice as long as the engine.

it's systems, not components that matter.

Re:Still a ways to go

[haruchai]

Have a look at molten-air batteries - http://phys.org/news/2013-09-m...

With an iron anode, the energy content is roughly the same as petrol - ~ 10000 watt-hours per liter. But the most you can hope for an a straight gasoline ICE is about 30%, whereas a battery is likely to be 2.5x as efficient. A carbon anode, which is more likely to be developed is nearly double that of iron so if this tech pans out and it looks to be quite affordable, it'll kill the demand for fossil fuels in almost all light-duty vehicles and make it possible to have hybrid long-haul trucks.

Re:Still a ways to go

[inhuman_4]

Aircraft are very sensitive to the weight. But ships are not. I wonder if it would be realistic to have a battery powered ship for cross ocean voyages. Especially for things like tankers and cargo ships. Pull into port and get hooked up with special massive power tx lines and fill up the battery.

I seem to recall that large ships are a big source of CO2 emissions. If it is possible I wonder what the trade off is in terms of costs.

Re:Still a ways to go

[anubi]

NoScript.

Re:Still a ways to go

[Neil Boekend]

How big a part of the power requirement of a ship could be covered by solar panels on the deck?

Re:Still a ways to go

[manu144x]

Why is everybody forgetting about how much of that energy an ICE Gas engine converts into motion? Roughly 15% ? A diesel goes up to 25% if i remember correctly. An electric engine is easily over 90% even 95%. I agree, the electric solution is still far from being better right now, but the fight is NOT only about energy/kg it's also about energy/actual useful movement too. It's a balance of both these things, makes no point to have 100 gallons of gas if you're gonna throw out 85% of it out.

Re:Still a ways to go

[Calinous]

A supertanker has a deck about 300 by 30 meters, so 10,000 square meters. With an optimistic 100W from square meter, and 8 hours a day of full power, you'd get about 8 MWh (or some of 28,800 MJ) of energy a day. At 43 MJ/kg for diesel fuel, that's the equivalent to some 700 kg of diesel fuel a day.
      Now, ships use heavy fuel oil when outside territorial waters (which is much cheaper), so a full deck of solar panels wouldn't save you very much money. And those panels would be exposed to salt water, storms and so on.
      I haven't found the "common" power generation for ultra large crude carriers (oil tankers), but max power seems to be over 80MW - assuming they're going at a quarter of maximum power, the solar cells would give you at most 1/60 of the needed power per day.

Re:Still a ways to go

[Neil Boekend]

700 kg of fuel equals about an hour of usage. However, if the ship is all electric one can assume a 3x as efficient powertrain, so 3 hours. If we combine the solar panels with a skysail which provides around 2000 kW continuously we would get an additional 48 MWh or 172,800 MJ (depending on shipping routes). This equals to approx 4000 kg/day without efficiency improvements or 5.7 hours. With a powertrain efficiency improvement of a factor 3 (doable when using electric power) this would equal to 17 hours of boating.
With the 3 hours of solar boating we'd have 20 hours a day of clean shipping. Since required power is approximately related to speed squared, having a bit lower speed would offer a lot less fuel usage. Low speed is already a disadvantage, but with moder consumer wishes a "Sustainable inter continental shipping" logo splashed everywhere would probably increase sales for your customers. Maybe DHL could advertise long delivery time green shipping thing.

To get back on topic: Batteries. Large container ships are meant for long distances, so we can assume the ship will be on the ocean for months at a time.
If I assume lithium sulfur batteries have a voltage of 3.5 V (from Li-Ion batteries) I assume 3.5 Wh/g or 12,600J. We need about 30,100,000,000J/day so that's 2,388,888 g or 2.4 metric tons. To go 3 months you'd need 223.2 metric tons of these new batteries.
Container ships are big, in the order of 50.000 metric tons so it would be possible. However the price of these batteries isn't known yet and it may just be more expensive than a skysail and a deck of solar panels.

With this back of the envelope calculations I think now that the solution would be in the category of SkySail + solar panels + batteries. Cruise on SkySail + batteries and top the batteries off with the solar panels if you can.
As for the corrosive environment: Glass doesn't corrode and the rest can be covered in plastic which doesn't corrode either. They should be fully sealed of course so there are no metal parts in contact with the corrosive air.
I just think the maintenance crews aren't going to like it much. It would require a lot of retraining.

Note: I am an engineer. However I am not an experienced engineer in this field.

Re:Still a ways to go

[Rhywden]

Definitely looks interesting, but highly unpractical for vehicles. After all, you have to keep the metal molten all the time. And that means some heavy-duty insulation, something akin to a Thermos bottle with a large volume. The problem then is the fact, that such bottles are not exactly great when it comes to vibrations, abrupt stops and crashes.

Re:Still a ways to go

[140Mandak262Jamuna]

They achieve the high densities by using atmospheric air for oxygen. Basically they are rusting iron and reversing the rusting using electrolysis. Which means not only you need to keep the iron molten, you need to vent it to atmosphere too! Other molten metal batteries are sealed, allowing for better thermal insulation.

Re:Still a ways to go

[haruchai]

There's already the ZEBRA battery, used in a few EVs since 2007. I think insulation isn't such a big problem when the batteries are large as there's a fair bit of thermal mass. The threshold for the ZEBRA is somewhere upwards of 20 kWh but that would depend on the shape.

The Tesla Model S which used a flat, relatively thin pack on the floor of the vehicle would definitely be a challenge.

Re:Still a ways to go

[haruchai]

There's also a carbon anode which I suspect would be the focus of development. It's not likely they'll put too much effort into vanadium boride in the short-term.

Many exciting developments in batteries

[cold fjord]

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

Re:Many exciting developments in batteries

[haruchai]

Here's another that's very energy dense - molten-air batteries: http://phys.org/news/2013-09-m...

If you want something that's closer to commercial production, keep an eye out for Sumitomo's low-temp molten-salt battery, due in the next year or two.

Re:Many exciting developments in batteries

[bluefoxlucid]

The varying lifetime is less important than people think. If you have a 300 mile range electric vehicle battery that can handle 1,000 charges and you replace it with a 3,000 mile range battery that can handle 100 charges, you can still go 300,000 miles. It just turns out you can go 3000 miles in one trip.

Quick Discharge batteries?

[Freshly Exhumed]

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!

Re:Quick Discharge batteries?

[Nemyst]

Huh? mAh is a unit of charge, not current. It's a bit like kWh that's generally used for electricity costs.

Re:Quick Discharge batteries?

[skids]

This. And the goal of this line of battery research isn't to provide "blasts of current" as we've already got that covered with ultracaps and Li-ion for burst needs. The goal is to provide slightly more current than is required to propel a vehical at highway speeds, and do so for a long time between charges, and to do so for many charges.

could and should and all that

[turkeydance]

where's my flying car?

Re:could and should and all that

[Required Snark]

First, you have to prove that you deserve a flying car.

Then you have to prove that you can be trusted to dive/pilot a flying car.

Given how the vast majority of people drive, almost no one passes the second test.

I'm not claiming that I do either. I also know that I should not ride a motorcycle because I don't have the right kind of attention for it.

Re:could and should and all that

[Lumpy]

at the airport, go get your recreational pilots license and then get ready to pony up $250,000 for it, or less if you will accept used, but only poor people would buy used.

Cessna and other companies have several choices for you.

Re:could and should and all that

[causality]

First, you have to prove that you deserve a flying car.

Then you have to prove that you can be trusted to dive/pilot a flying car.

Given how the vast majority of people drive, almost no one passes the second test.

I'm not claiming that I do either. I also know that I should not ride a motorcycle because I don't have the right kind of attention for it.

With a motorcycle your main problem is the other drivers.

What you would discover (or be reminded of) is that average people don't put any thought or attention energy into anything that isn't directly in their selfish interests. George Carlin called it stupidity and consumerism, Erich Fromm called it alienation, I call it spiritual infancy. Regardless, that's the deal. The SUV driver doesn't see your little motorcycle as a threat and isn't likely to spend much time looking out for you (meanwhile they can't move out of the way fast enough for a merging tractor-trailer - see how that works?). You have far more to lose in such a collision.

If you actually talk to motorcycle riders (at least in the US) you'll hear the same thing over and over.

Still a ways to go...until we get where?

[Immerman]

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.

Re:Still a ways to go...until we get where?

[TubeSteak]

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."

This is also a complete lie.
AFAIK, all batteries have a certain rate of self-discharge.
Lithium ion self-discharges at about 2%~3% per year, unless you keep it refrigerated.

Re:Still a ways to go...until we get where?

[strack]

Don't forget that gasoline engines typically turn only about 20-30% of the chemical energy into mechanical energy, whereas electric motors are about 90%. And you get rid of a heavy gasoline engine.

Re:Still a ways to go...until we get where?

[Anonymous Coward]

Energy density is more important here... not specific energy.

the Tesla model S will be using new Panasonic batteries, quoted at 735wh/L, or 2.65 MJ/Liter
Gasoline is ~36 MJ/Liter

so that's an order of magnitude difference.

BUT

Electric cars are 3 to 4 times more efficient at taking electricity and converting it to forward motion that an internal combustion engine. This is basically due to the fact that 1) electric motors are about 90% efficient, with IC about 30%, and electric cars can get energy back when braking.

So... instead of 36/2.65 = `3.6 times better for gas it's more like

36/(3*2.65) = 4.52 times better for gas

So yes... we are almost there.

Re:Still a ways to go...until we get where?

[Anonymous Coward]

that was supposed to be

  of 36/2.65 = 13.6

little typo there...

Re:Still a ways to go...until we get where?

[riverat1]

... so I doubt we'll see electric jetliners any time soon.

You're right but electrically powered propeller airplanes already exist. They just need better batteries to have enough range to be practical.

Re:Still a ways to go...until we get where?

[cheesybagel]

You use a propeller. That is known to work.

Re:Still a ways to go...until we get where?

[cheesybagel]

Or power beaming. Remember this?

Re:Still a ways to go...until we get where?

[skids]

Ah, so we're throwing the aircraft through the air with the power of pixie dust and unicorn farts.

Aircraft engines are a red herring here, since the target of these batteries is automotive. But for what it's worth, jet turbines also only convert a portion of the fuel's chemical energy into kinetic energy. Combustion efficiency is 90%+, but cycle efficiency in turbojet and similar is nearer to 30%.

For automotive, in contrast to ICE+drivetrain at about 25%, shows average values of about 36% and this is in part due to the efficiency of electric drive trains and in part due to the efficiency of the fuel cell process, but of course externals in the fuel production.

Batteries win hands down against both of those options for efficiency, with externals excluded, so the same amount of energy in a battery is worth more miles than the equivalent amount of chemically stored energy in gasoline once it is onboard.

Re:Still a ways to go...until we get where?

[strack]

I guess he doesn't know. I imagine there's a lot of things he doesn't know.

Re:Still a ways to go...until we get where?

[TubeSteak]

I misspoke by using the words "self discharge."

Lithium Ion batteries lose a fixed amount of capacity every year, regardless of usage.
The only way to slow this process is refrigeration, which slows the chemical reaction that reduces capacity.

Even howstuffworks mentions it.

Re:Still a ways to go...until we get where?

[petermgreen]

On the other hand fuel weight is lost as the energy in the fuel is used battery weight stays with the plane for the entire flight.

Re:Still a ways to go...until we get where?

[cbhacking]

Took me a moment to realize you were talking about fuel cells in the "36%" part; maybe you forgot a few words? Anyhow, no worry.

Yeah, heat-based engines have pretty poor efficiency. We just can't get the "cold side" to be very low in practice. I'm not sure if we'll ever really beat this problem. There are lots of other systems out there, though...

Mind you, electrics have their own host of inefficiencies. There's resistive losses (both within and outside the battery), losses to regulation circuitry, some of the same drivetrain losses as a car (avoiding a conventional transmission surely helps, but there is still some friction in the moving bits, as always), and probably a ton of other things I haven't thought of. I can well believe the inefficiencies of a conventional ICE-based car are several times as bad as those of an electric, though, which means a factor of 5x improvement in battery capacity could let batteries substantially beat hydrocarbon fuels on a usable-energy-per-volume metric, and be within one order of magnitude on mass as well.

Re:Still a ways to go...until we get where?

[Joce640k]

So yes... we are almost there.

Apart from the recharge time...

If recharge time was a minute or two then a car with 200 miles range would probably be good enough, and we already have that.

It's the "overnight" part that's keeping electric cars off the road right now.

Re:Still a ways to go...until we get where?

[strack]

If you get it to the point that you can drive the car all day on a full battery, the "overnight" part wont matter so much.

Re:Still a ways to go...until we get where?

[strack]

Um, what? Specific energy is wh/kg, and is much more important than the amount of volume the battery takes up. Pushing extra battery weight around takes more energy, extra volume isnt that hard to deal with.

Re:Still a ways to go...until we get where?

[BlackPignouf]

"Only two orders of magnitude"?
Well, that's the difference between flying and staying on the tarmac.

Re:Still a ways to go...until we get where?

[Mashiki]

Don't worry, there's half a dozen replies that missed the sarcasm and humor in my post. You just happen to be one of them, so I have to ask what's the world like living in a state where there's no humor in it?

Re:Still a ways to go...until we get where?

[Lumpy]

So keeping my laptop in the car this winter was good for the battery?
sub zero temperatures have been preserving my laptop!

Re:Still a ways to go...until we get where?

[Lumpy]

10 hour battery life no matter it's city driving or steady at 80mph on the highway tailgaiting people and road raging.

Re:Still a ways to go...until we get where?

[Mashiki]

Ah, the classic "well I thought I was being funny, what's your problem...?".

Perhaps, you're not as funny as you think...?

Don't worry AC, after all if you actually had something more worthwhile to say you'd have attached it to your name right?

Re:Still a ways to go...until we get where?

[strack]

well, you attached your name to some sarcastic pablum, and it still didnt make it worthwhile to say. But hey, at least now you know 1 more thing than you did before. have a gold star.

Re:Still a ways to go...until we get where?

[beanpoppa]

At the risk of sounding 'Applely', Think different. Right now, I have to stop to 'recharge' my ICE car for 5-10 minutes, once a week. That's, on average, about 6 hours a year I wait for my car to 'recharge'. If I had an electric car, I would be plugging it in every night. For most weeks of my commuting year, it would eliminate any time waiting at the gas pump.

Re:Still a ways to go...until we get where?

[Immerman]

Actually AC is correct - for aircraft where you have to continuously fight gravity weight is pretty important, for cars... not so much. Especially with regenerative braking. More weight does reduce efficiency, but it's volume that the limits the number of batteries a standard-sized car can reasonably carry. If you can store 5x the energy in the same volume, but at 5x the mass, it's still a major win. The loss in efficiency means your range won't increase 5x, but 3x is probably easily attainable. And 5x the mass would be a real challenge to attain unless you're using a lot of uranium or something.

Re:Still a ways to go...until we get where?

[Immerman]

Well, since the charging stations mostly don't exist at present there's nothing to replace, though the thicker wire required for a higher-power charging station would increase the expense of new construction somewhat. And for household charging, well, very few people are going to be traveling 1000+ miles a day, most of the extra capacity is so that on the rare occasions you do, your battery has plenty of charge. If it takes a few nights to get back to a full charge after a trip to grandma's house that's probably not an issue.

Re:Still a ways to go...until we get where?

[JesseMcDonald]

That's, on average, about 6 hours a year I wait for my car to 'recharge'. If I had an electric car, I would be plugging it in every night.

That's assuming you spend no time plugging your vehicle in at night, unplugging it in the morning, or otherwise managing the charge level. The breakeven point is only about 80 seconds per day.

Re:Still a ways to go...until we get where?

[mattack2]

How often do you go to the gas station?

Why not charge overnight at home, or during the day at work (if you happen to have EVSEs there)? There's PLENTY of time when your car isn't being used that it could be being charged.

Even the lowest range electric cars have far more range than the average commute.. (I recently got one with one of the lowest ranges -- smart electric.)

Re:Still a ways to go...until we get where?

[Gallomimia]

They already have cordless electric car charging stations. Put it on the floor of your garage at home, drive in, walk inside, forget about it. Takes zero time to manage your charge.

Re:Still a ways to go...until we get where?

[demonrob]

yes people, this is an interesting discussion, but we do really want to know about the efficiency of unicorn farts. I've heard so much mentioned of them lately but no hard core mathematics or science about it. Do we need to ask the CSIRO for an opinion once they have finished their dragon reasearch?

the important questions

[Gravis Zero]

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?

Re:the important questions

[Intrepid imaginaut]

3) Behind the third cushion on the right in your couch /NSA //You're welcome

Re:the important questions

[Jack Griffin]

1) are these expensive to make?

This is what I came here looking for. 100 cycles is perfectly acceptable if the battery costs 25 cents. But I guess I'll die wondering...

Maybe

[no-body]

Some kind of modular system where a standarized batterypack is used which can be refurbisched with material (sulfur) reused?

Sulfur batteries

[Anonymous Coward]

Smells fishy to me.

Not for Cars, uh uh!

[Radtastic]

Sulphur Batteries?!!!? The exhaust is gonna smell like rotten eggs!

They can use the sulpher ...

[riverat1]

... they're taking out of gasoline for them.

Erroneus's law

[erroneus]

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?

Re:Erroneus's law

[Concerned Onlooker]

"So is it me or are they creating batteries out of just about everything?"

It's not just you. http://hilaroad.com/camp/proje...

Re:Erroneus's law

[mjwx]

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?

I'm going to counter this with the Grandpa Simpson principal which states "everything gets worse as you get older and you will complain about it".

Try beating an airliner turbine

[dutchwhizzman]

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?

Re:Try beating an airliner turbine

[Lumpy]

The small fact that air movement is a very very low efficiency way of making a plane fly. Actual thrust like from a jet engine is far more efficient.

Turbofans are simply cheaper to make and operate.

Re:Try beating an airliner turbine

[NoImNotNineVolt]

Isn't thrust, um, air movement?

mAh is only half the equation

[imsabbel]

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.

Re:mAh is only half the equation

[Donwulff]

Well, amount of energy per mass. But amount of energy per volume will come a close second, and unless they have unlimited charge cycles with no degradation, energy per dollar will be sharing that close second position. Charge efficiency is probably around third most important, and whether it's prone to exploding randomly in a fiery conflagration is up high there as well. In short, almost anything else than what was actually provided in the summary :)

Re:mAh is only half the equation

[Twinbee]

Are you saying..... wow... we should (god forbid) measure, energy capacity in....... watt hours (or joules)? How dare you recommend such a statement!

Honestly it amazes me the number of people who think volts or amps alone constitute energy. It also saddens me that watts and watt-hours are not more commonly stated in products such as on battery labels.

Re:mAh is only half the equation

[wvmarle]

When looking at electronics recently, specifically little ICs, they always specified the power usage in units of current.

It seems that the reason is that semiconductor ICs can handle a broad range of voltages, like 3V-15V, and use roughly the same current at the whole range. As long as your supply voltage is in that range, the components are happy. The same when powering LEDs, they need a certain current, and any supply voltage will do as long as it is high enough (you always have to add a resistor to regulate the current).

So giving power capacity of a battery used for supplying power to semiconductors in mAh is not exactly strange.

Re:mAh is only half the equation

[Big_Breaker]

Compressed air has volumetric energy density similar to lead acid (about half lithium ion) but extremely high power density. Energy density by weight is dependent on scale - bigger is better - because the weight scales as the surface area of the container while the energy scales with volume. But

If you are looking for a power boost on take off, compressed air is totally viable. Doubly so because it would naturally drive a propeller with an air motor which is more efficient at low speeds. Fix the expansion cooling by burning a bit of fuel in the expansion stream.

I won't want to be near a high pressure tank like that if it ruptured though! Maybe its a system that works better for cargo than human transport.

Re:mAh is only half the equation

[crunchygranola]

In other words: high power density = propensity to explode.

1,225 mAh

[multi io]

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.

Re:Forget cars

[Neil Boekend]

You recycle batteries. The elements are not wasted, usually they lost their specific shape or a not intended molecule is being formed once in a while, and that molecule does not release electric energy. All these things are reversible.
In fact, never ever throw a battery in a landfill. Most are quite bad for the environment when not recycled properly.

Re:Forget cars

[Joce640k]

I'm not looking forward to garbage lots filled to the sky with used batteries.

Is it as bad is the air being filled to the sky with CO2?

Lithium Ion lifetime - really ?

[bheading]

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.

Re:Lithium Ion lifetime - really ?

[afidel]

Look into low self discharge batteries, the Eneloop second generation batteries maintain 75% of their charge after 3 years without use and can be fully charged for 1500 cycles. The third generation cells go to 90% after 1 year and 70% after 5 years but they're enough more expensive at this point that they're not worth the extra cost for most applications, they've also increased the stability a bit to 1800 cycles.

Molten sulphur is pretty nasty stuff

[Viol8]

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.

What are they waiting for?

[wvmarle]

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!

Dat envelope

[strack]

Lets see what the range on a typical light aircraft would be if you ripped out the full fuel tanks and gasoline engine and stuffed it with a equivalent power electric engine and these new batteries to the same weight. So it says it will store 4-5 times as much energy as todays best lithium-ion batteries. the best li-ion today is lithium cobalt, at about 165 wh/kg. So x4 of that is 660 wh/kg.

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.

Re:Dat envelope

[strack]

actually, i should probably lop off about 30km range to account for energy losses from the electric engine.

Re:Dat envelope

[140Mandak262Jamuna]

Electric motors are extremely efficient, over 99% in converting electricity to mechanical energy. So you don't have to lop off so much for the efficiency of the electric motor. But, how much of the energy in the battery can be actually extracted is the question. If the energy densities quoted were based on "available energy" you don't have to account for it. But if it is based on some theoretical value based on how much can be packed in, without worrying about how much of it will come out, then you need to account for that loss.

Re:Dat envelope

[strack]

well its true, i dont know the conversion from mah/g to kwh/kg here, but im going on that 1005mah/g figure stated, and its comparison to the 200mah/g for a current lithium ion battery. and im being conservative, using the 4x multiplier instead of 5x. And since they say charge-discharge cycles, i presume they measured the energy coming out of the battery.

Re: Dat Envelope

[catprog]

probably about .8 to 1.6Kw of solar power.

Re: Dat Envelope

[demonrob]

maybe add a couple of wind turbines as well?

Anyone working on liquid charged electrolytes?

[140Mandak262Jamuna]

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.

Still could beat standard Lion

[Anonymous Coward]

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.

Re:Forget cars

[jbmartin6]

We need something to displace all the nitrogen. That stuff is dangerous!

Re:ICE 20% efficient, Electric 98%.

[Adriax]

I was going to say only long mission military jets do mid-air refueling so the point is irrelevant, but then I re-read your post.

How exactly does an airplane refuel itself in mid air? Magic second tank that stores extra fuel in a way that doesn't take up the same weight/space a normal tank does?

Works for me.

[Whumpsnatz]

"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.

Re:Forget cars

[cowwoc2001]

One is proven by science. The other is "proven" by Al Gore :)

What I resent about the latter is that there was plenty of scientific evidence before/after Al Gore's stupid movie, but that bit of "science" only got momentum because of the movie. We shouldn't make decisions based on what's popular. We should make decision based on scientific fact.

So to reiterate: I'm not arguing whether Global Warning exists or not, but rather that it's stupid that people only began saying it exists because that movie came out.

There are plenty of non-controversial gasses that we know for a fact kill people every day, but instead we're pouring billions of dollars into something controversial for popularity reasons.

I hope some of these pan out

[peter303]

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.

not even that far

[s122604]

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.

Re:not even that far

[mattack2]

Why do you have to drive *200 miles in one single trip* so often?

Hopefully Stable and NOT explosive!

[foxalopex]

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.

Re:Forget cars

[romanval]

The scientific consensus for AGW/climate change was pretty darn clear even before Al Gore's movie: He just made it more popular. The only people making it controversial are the old school energy companies and everyone associated with it.

Re:Forget cars

[crunchygranola]

...

So to reiterate: I'm not arguing whether Global Warning exists or not, but rather that it's stupid that people only began saying it exists because that movie came out.

...

I am tempted to say something is indeed stupid here, but it is not what you are claiming is stupid.

Three dates:

• 1992: Due to the growing scientific consensus on the reality of anthropogenic global warming the UN establishes the Framework Convention on Climate Change, which leads five years later to:
• 1997: the Kyoto Protocol on limiting greenhouse gas emissions being negotiated;
• 2006: An Inconvenient Truth, narrated by Al Gore comes out.

"People began saying it exists" well more than 15 years before "that movie came out", and it was a political hot topic in the U.S., frequently discussed, for a decade before the movie. Your notion that "that movie" somehow created this out of nothing is so profoundly ignorant that it leaves one gasping in awe.

great for RC

[AndrewFenn]

even with just a 100 charges a battery that has 1.2 A per gram sounds awesome for RC flying.

Sulfur-based polymer?

[XNormal]

In the 1960s there was research into sulfur-based polymers but apparently ran into some problems:

"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

Re:ICE 20% efficient, Electric 98%.

[Gallomimia]

How exactly does an airplane refuel itself in mid air? Magic second tank that stores extra fuel in a way that doesn't take up the same weight/space a normal tank does?

What the hell do you mean "how does it refuel in midair?" It flies up to a refueling tanker or blimp and takes on fuel through a big hose. http://en.wikipedia.org/wiki/A...