World's First Battery Fueled By Air 205
Hugh Pickens writes "The Telegraph reports on the revolutionary 'STAIR' (St Andrews Air) battery could now pave the way for a new generation of electric cars, laptops and mobile phones. The cells are charged in a traditional way but as power is used an open mesh section of battery draws in oxygen from the surrounding air that reacts with a porous carbon component inside the battery, which creates more energy and helps to continually 'charge' the cell as it is being discharged. The battery has a greater storage capacity than other similar-sized cells and can emit power up to 10 times longer. 'The key is to use oxygen in the air as a re-agent, rather than carry the necessary chemicals around inside the battery,' says Professor Peter Bruce of the Chemistry Department at the University of St Andrews. 'Our target is to get a five to ten fold increase in storage capacity, which is beyond the horizon of current lithium batteries.'"
Question (Score:5, Interesting)
Would there be any danger of using this in a confined space? Any clue on how much oxygen this thing is churning through?
Re:Question (Score:5, Funny)
Would there be any danger of using this in a confined space?
Only if you had beans for dinner.
Re:Question (Score:5, Funny)
At least, that is unless you had some kind of highly complex extraction [bizfriendmarketing.com] device [toolstation.com] to remove the oxygen build up.
Re:Question (Score:5, Interesting)
Ummmmm... I am more referring to its consuming oxygen that might otherwise be used for breathing.
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I guess I should maybe, you know, open a window, or open an air vent?
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That might be interesting on an airplane. So the question becomes, if this battery is so awesome, and it is used in laptops, then what? Do the airline begin banning laptops on their planes? Only ones that have this type of battery? How do they check?
So, getting back to the original question which TFA does not answer: how much 02 does this thing consume?
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Re:Question (Score:5, Informative)
I don't think it's that awesome. Air batteries (which are nothing new, BTW), tend to suffer from poor cycle lifes, poor power density, and very low efficiency. Often these "breakthroughs" aren't as impressive as they at first sound.
Now, that said, the other recent battery breakthrough -- on the Li-S front -- really does look as impressive as it sounds. I read through the paper on the research the other day as "light reading" at the dentist's office ;) Li-S's big problem has long been its really atrocious cycle life. It has great energy density, good power density, and very good efficiency, but the cycle life is a killer. And the variants they tried to improve cycle life really shot the energy density.
The reason it has these cycle life problems is because of how it works: you have sulfur in a carbon matrix (needs a conductive matrix because sulfur is an insulator) on one side of a separator film and metallic lithium on the other. The lithium ions migrate across the membrane and bond with the (insoluble) sulfur cathode to form (insoluble) Li2S; then, when running the cell in the other direction, the Li2S is split and the ions migrate back to the metallic anode. But there are intermediary reaction products -- various lithium polysulfides -- and these *do* tend to be very soluble. So, some of the polysulfides dissolve into the electrolyte, migrate across the membrane, and precipitate out on the other side and are rendered useless.
The new technique is pretty clever. They start by making a form of mesoporous carbon. This is made kind of like aerogel, via nanocasting, and it's covered in really deep pits. They then mill and then heat together the sulfur and carbon. The sulfur, having low surface tension, wicks into all of the pore space, with only a small amount of room left over to account for expansion. They then bake the composite at 155C, which boils all of the sulfur off the surface, leaving it only in the pits. So when the polysulfides form, they have a lot of trouble migrating out of the carbon.
That alone is a big improvement, but they took it a step further. The polysulfides are hydrophobic, so they bonded polyethylene glycol to the exposed surface of the carbon to make it repel the polysulfides. So now they have even more trouble migrating out of the pore space. To show how well they have them trapped, they took a traditional Li-S cathode and used a worst-case electrolyte -- something that loves to dissolve polysulfides. After 30 cycles, 96% of the sulfur was gone. With their cathode in the same worst-case situation, only 26% was lost.
In normal coin cells, their tests showed an initial capacity of around 80% of the theoretical maximum, falling about 15% in the first few cycles and then plateauing, nice and stable. The theoretical maximum for Li-S, if you discount everything but the sulfur, is 2,500Wh/kg (the best li-ion batteries on the market are 200Wh/kg). Now, obviously, you can't discount everything but the sulfur. The sulfur:carbon:lithium ratio, by weight, works out to something like 7:3:2. So, excluding the electrolyte, separator, and casing (which should be small components on large-format prismatic cells), they should get about 950Wh/kg. I imagine in a large format cell, they could probably get 800-850 -- over 4x the best current li-ion. Also, it's quite convenient that all of the raw materials are cheap and have low toxicities.
Re:Question (Score:4, Funny)
THE WALLS ARE CLOSING IN, MAN!
Re:Question (Score:5, Funny)
Mods must be having a bad day, or just not reading TFA. Oh yeah, this is SlashDot. Par for the course.
Re: (Score:3, Insightful)
What do you expect, with all the new users that came over from 4chan now getting into to "eligible for moderation" zone?
Just look at the amount of 4chan memes that pop up around here.
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IIRC, it never worked like that. A mod point can only be spent once. If you mod somebody up, and then post in the same thread, the moderation disappears along with your mod point - you don't get it back.
Re: (Score:3, Informative)
Yes, it would be extremely dangerous to use this near any source of ignition. At least, that is unless you had some kind of highly complex extraction [bizfriendmarketing.com] device [toolstation.com] to remove the oxygen build up.
Sigh. I had this serious reply written up explaining how you had it backwards - it removes the oxygen from the air etc etc ...
Then I clicked the links. Good thing, I would've earned a "whoosh" otherwise...
Re:Question (Score:5, Funny)
Who knows, but it certainly gives new meaning to vaporware.
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The main question is: Does it transform the oxygen, or does it get released on usage?
If it transforms it, then it should be a law, to plant an equivalent amount of plants (underwater or normal) so that the oxygen is transformed back.
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They consume carbon dioxide and release oxygen.
CO2 + 2 H2O + energy becomes CH2O + H2O + O2
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Please show me what part of that page makes you believe plants consume oxygen.
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Take a close look at your equation. See how energy is on the left, being used in photosynthesis? There's none on the left?
Plants metabolize sugars the same way you do, through respiration, consuming oxygen and releasing carbon dioxide. The difference is that they ALSO conduct photosynthesis, making those sugars they burn, instead of eating them. In general a plant will release more O2 than it uses because it stores away some of the extra carbon compounds in structural materials for the plant, fruit for you
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But, wouldn't you ultimately be using the same amount of oxygen regardless of the concentrator? i think your lungs are simply not having to work as hard to get the same amount of oxygen. Otherwise, you'd be hyperventilating. Or maybe I am not conceptualizing it correctly...
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Re:Question (Score:5, Insightful)
According to the article the lithium is oxidized to Li2O2, so 1 mole of lithium takes half a mole of molecular oxygen during discharge. If the battery contains 100g of lithium (a large laptop battery might contain this amount), a total discharge would need
100 g / 6.941 g/mol * 0.5 * 22.4 dm3/mol * (100%/20%) = 806.8 l
of air, or less that one cubic metre. The second figure is the atomic mass of lithium, the third is the ratio of the stoichiometric coefficients of oxygen and lithium in thhe reaction, the fourth is the molar volume of ideal gas, and the last is the factor from oxygen concentration.
So unless you are in a coffin this is not a risk.
Re:Question (Score:5, Informative)
Addendum: the same amount of oxygen would be liberated when charging. It could be a problem if you decided to charge it in an air-tight box, but under normal conditions it won't be a problem.
Re: (Score:3, Interesting)
On a sidenote, I've always been confused as to why chemists feel the need to use a ridiculous word like "stoichiometric" for such a simple concept as "ratios", which is already a weird enough word. Science is confusing enough without stunts like that, thankyouverymuch.
Powered by Air? (Score:5, Funny)
Re:Powered by Air? (Score:5, Insightful)
Nice headline Taco.
This is "fueled by air" in the same way an internal combustion engine is.
This is a Lithium battery. Why isn't Lithium in TFS?
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You're trying to be funny.
The Carbon's there only to help hold the catalyst in place along with allowing oxygen from the air into the system to react.
Li-Ion batteries are fueled by oxides (Lithium Cobalt Oxide...) in the battery. If I'm understanding this correct, the battery consumes ambient oxygen while it's discharging and produces it when it's being recharged.
So it is Carbon neutral as it doesn't put CO2 into the environment.
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Re:Powered by Air? (Score:5, Funny)
Re:Powered by Air? (Score:4, Informative)
Well, it's a lithium battery, that also includes an in-situ carbon fuel cell to replenish itself.
No, it is not. The carbon is only an adsorbent/catalyst matrix. Otherwise it would not be rechargeable. The first article contains misleading wording. Read the second one, or this one: http://www.theregister.co.uk/2009/05/19/lithium_oxygen_stair_battery/ [theregister.co.uk]
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Dang, you mean this new invention will be no more useful than the internal combustion engine? Snore.
Actually it sounds good to me. There's a reason we don't use rocket engines in our cars. Oxygen is highly reactive and available on earth everywhere there's air. Most batteries don't take advantage of that, so this one might be better. I liked the idea of the methanol-powered fuell cell [gizmag.com] "batteries" that several companies tried t
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This is much more than an ordinary lithium battery, and the headline is quite appropriate. Internal combustion engines are in a very real sense "fueled by air", as are our own bodies, and using the same principle to extend the life of batteries without increasing weight or volume is a very good idea. It's not totally unprecedented, either, as zinc-air batteries do this; the innovation is making them rechargeable.
Re:Powered by Air? (Score:5, Informative)
Agreed. It's not even the first battery powered by air in this manner. As Taco ever heard of zinc-air batteries [wikipedia.org]? These are commonly used in, among other things, hearing aids.
Re:Powered by Air? (Score:5, Funny)
Thank you, thank you... Try the duck, the veal is off tonight.
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The point of this battery is that when you charge it, the oxygen is emitted again.
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In chemistry, we have these cool things called catalysts.
See, a catalyst is used in a reaction, but is not used up in a reaction - it just provides structure for the reacting molecules to bond more easily.
See, in this case, the carbon is providing structure - acting as a catalyst - for the Lithium to bond with Oxygen on the fly, instead of having to be pre-bonded and stored prior to use, which is how all other lithium batteries work.
Think of it as a normal lithium battery, but with half the chemicals pulled
Any side-effects or drawbacks? (Score:5, Interesting)
Sometimes things sound too good to be true. Risk-free money smuggling from Nigeria. Enormous genitals from a few pills. Whiter teeth using only household chemicals. Articulate and clean presidential candidate who seems like he can fix anything.
Extending the life of batteries using the air sounds like a great thing. But what is the hidden problem that we are overlooking here? Will the chemical reaction of the battery and oxygen deplete the batteries faster than standard LIon? Are the batteries heavier? Output less power? Require usage patterns that aren't typical for normal users?
It just sounds too good to be true.
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Not necessarily -- the carbon could act as a catalyst or component that is cycled throughout the charge-discharge process.
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but O2 -> O2 isn't a reaction so the Oxygen HAS to react with something.Experience suggests carbon is the best candidate to react, so carbon as a catalyst is unlikely.
Re:Any side-effects or drawbacks? (Score:5, Informative)
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Presumably the oxygen is going to released again when you recharge the battery. That's what recharging is, reversing the chemical reactions that took place during the discharge.
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Oxygen-carbon reaction is not used to generate power in this design. Read the second article and especially the picture, because the first one has no useful information. It might happen as an unwanted side reaction, but the actual reactions that produce energy are:
CnLi -> Li+ + Cn + e (Cn = graphite, CnLi = graphite-lithium intercalate)
2Li+ + 2e + O2 -> Li2O2
It's lithium that's oxidized (to lithium peroxide), NOT carbon. Carbon and MnO2 only make this reaction possible (my guess is that it's because p
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IANAC (chemist), but it sounds like what they are doing is take a reagent for the electrical reaction from the surrounding environment so they don't have to store it on board the battery -- thus freeing up additional weight/volume for the "charge" itself.
This might imply a problem with scale since you would need the infrastructure within the battery for safely extracting the reagent and, upon a recharge cycle, releasing it.
I wouldn't be surprised to see something like "DO NOT RECHARGE NEAR AN OPEN FLAME" wr
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Sort of like the "DO NOT PUT IN FIRE" already on every battery we produce? If these things put out enough oxygen to produce a localised fire hazard while recharging, well they must be recharging pretty damn quick. I would consider this a feature. It seems to me all we would need to do to mitigate this risk (if it is even there) is make sure the recharging stations have a little fan in them to disperse the oxygen quickly.
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Re:Any side-effects or drawbacks? (Score:5, Insightful)
Those are the potential problems I can see:
1. The batteries will degrade over time, because the porous carbon used as the catalyst will slowly oxidize away.
2. Moisture sensitivity might be a problem. Graphite-lithium intercalate used in the negative electrode is, as far as I know, not resistant to water. Li2O2 also doesn't look stable (Na2O2, a close analogue, decomposes when subjected to moisture)
3. Total life might be additionally shortened in cities with smog. Smog contains highly oxidative species like nitrogen oxides and free radicals, which would accelerate the degradation of the carbon catalyst.
4. Obviously it won't be suitable for waterproof equipment.
5. Maximum power output might decrease with altitude (lower oxygen partial pressure).
The main problem is that you can't control the quality of air around the device, so I predict that preventing the battery from degrading when the air is not 100% clean and moisture free is going to be a challenge.
Wow. (Score:3, Interesting)
Re:Wow. (Score:5, Insightful)
This might be an exception (hopefully), but until you can get one off NewEgg people stay cool and cautious.
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Buy shares now (Score:2, Interesting)
Is it rechargable? (Score:5, Interesting)
We have zinc-air elements for decades now, but they are not rechargeable.
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The second link in the article says yes, it is rechargeable.
Re:Is it rechargable? (Score:4, Informative)
Well, given the summary (and the article it plagiarizes from) explicitly says:
Okay, sure, that's a little vague. 'course, if one were to actually go through the trouble of RTFA, you'd see this quote from the second article:
So, I would guess that, yes, it's rechargeable.
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These elements, according to the coverage at The Register, are lithium-oxygen. The porous carbon storage matrix is just that, and plays more a mechanical role than a chemical one. I do so wish /. stories would link to articles that report science with at least the simplest facts right.
Re:Is it rechargable? (Score:5, Informative)
Rechargeable zinc-air battery, 4 years ago:
http://www.eetimes.com/news/semi/showArticle.jhtml?articleID=164903727 [eetimes.com]
I wonder whether they managed to take it anywhere. rechargeable zinc-air would be cool, because there's much more zinc than lithium on Earth.
Almost there (Score:5, Funny)
Re:Almost there (Score:5, Funny)
You are in luck [wikipedia.org].
(I love having to wait five minutes between posts)
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When I can plug a carrot into my portable $whatever then it would be useful, until then it has nothing to do with electrical charge, which is what this story is all about.
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You can burn a tree and use the energy for something useful. Then plan another tree and remove the carbon from the air. You'd almost think it was a renewable source of energy.
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It is.
Trouble is...it's not economical to plant new ones and wait for them to grow.
Not without government subsidies to put a stop to the ever prevalent whine: "What's in it for me?"
It's far cheaper to raze and burn a forest and loot all the wood as fuel and then leave it for dead than it is to take proper care of it.
Of course, replanting becomes economical when wood becomes scarce, but by then the greedy bastards responsible for the shortage in the first place are long gone, having already laughed their way
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Sorry, I don't think this is entirely true. I know my grandmother owned several hundred acres in Alabama. A company contracted with her to use her land for wood. Part of the contract was that it would not be clear cut, and trees would be planted to replenish. Part of that contract also stipulated that they would exclusively have the rights to repeat the process a number of years later under the same contract.
I agree that there needs to be a federal ban on clearcutting and regulation on how it may be cut dow
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Hearing aids and Zinc-air batteries (Score:5, Interesting)
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The compact designs could not be recharged though.
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Questions (Score:3, Interesting)
1) Energy density - including ventilation
2) Physical expansion during charge/discharge.
3) Degradation with each cycle - i.e. how many recharges before capacity is reduced xx%.
4) Performance over temperature range (-20C to say 60C)
5) Durability of the material.
The list goes on and on. It sounds like a nice lab experiment at this time.
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So yeah, a lab experiment is all it really is at this point.
What's the output? (Score:3, Interesting)
If it's sucking in O2, what's the output?
Considering there's carbon in there my guess will be something along the lines of CO2 or CO.
Will this be better than burning fuel?
Then again, maybe it's not meant to be an environmental friendly solution, but more of an awesome-battery solution.
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It's lithium oxygen with a porous carbon storage matrix. The oxygen combines with the lithium, not with the carbon. The Register covered this [theregister.co.uk], and I'd say much better than The Telegraph. Then again, if there were two papers I'd expect to always be outdone by El Reg they'd probably be The Telegraph and The Daily Mail.
Re:What's the output? (Score:5, Informative)
Ok, second time I've had to do this; but, clearly the articles are pooorly written and do not describe the technology well, if at all.
It's a lithium-air battery in a carbon matrix. One electrode is lithium metal, one electrode is carbon. The oxygen, supplied by air and entering through the porous carbon electrode, reacts with the lithium to create lithium oxide. When the battery is recharged, the oxygen is liberated, returned to the atmosphere, and the lithium ions are returned to (plated on) the lithium metal electrode.
No CO2.
The output is electricity during discharge and oxygen during charging.
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There is no "output"; the carbon is only a catalyst/adsorbent. It's actually lithium that's oxidized, and lithium peroxide forms. Half reactions are as follows:
CnLi ---> Li+ + Cn (graphite) + e
2Li+ + 2e + O2 --C/MnO2 cat.-> Li2O2
The first is on the graphite-lithium intercalate electrode (not show in the article, but it's standard in Li-Ion cells).
billions of years ago (Score:5, Funny)
for billions of years, for billions of generations, strange archaic anaerobacteria and primitive algae slaved their entire lives, heck, their entire species, to make your atmosphere one fifth oxygen
all so you could one day watch the family guy on hulu.com at a starbucks in pasadena
doesn't seem just
Re:billions of years ago (Score:5, Funny)
Slaved? Slaved? Oxygen is their poop!!! We're finally just recycling the damn stuff. And yes I think that watching Family Guy on Hulu at a Starbucks is a fine use for archaic anaerobacteria poop... it's strangely fitting in fact.
Wake me in 2014 (Score:2)
Seems like every new thing is going to be commercially available in 5 years. Why can't we have the future now? Do I have to move to Japan?
Re:Wake me in 2014 (Score:4, Funny)
Seems like every new thing is going to be commercially available in 5 years. Why can't we have the future now? Do I have to move to Japan?
No, you had to move to Japan 5 years ago :P
Lithium-oxygen, not carbon-oxygen (Score:4, Informative)
This coverage at The Register [theregister.co.uk] says they are lithium-oxygen batteries. The porous carbon matrix is for containing the chemicals and allowing the oxygen in during running and out during recharging.
Battery weight (Score:2)
So the batteries oxidize lithium or some lithium compound as they discharge, and release the oxygen when charged.
Does this mean that the batteries actually increase, significantly, in weight as they discharge? And if so, is power to weight/energy to weight ratio considered while charged or discharged?
smells like hot air (Score:3, Informative)
creates more energy
Two problems here:
1. you can't create energy
2. reacting oxygen with some carbon substance is called combustion and while it does indeed burn, it doesn't make a battery
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Thankfully, the Telegraph and Slashdot both being what they are, it's not a carbon-oxygen battery at all. It's lithium-oxygen with a porous carbon matrix storing the lithium but allowing the oxygen to flow into and out of the chamber.
The air flowing in is actually what causes the usable energy to be released, as it is released by the oxidation of the lithium. It is recharged in a cycle of de-oxidizing the lithium.
Not the first (Score:5, Interesting)
This is kind of like a fuel cell (Score:2)
Subject (Score:2)
I hope you fucking hippies can still boast about how green your car is when the entire population of earth dies gasping for the oxygen your batteries stole. God damn you.
(readers who don't understand humor and wish to rebut me at length may form a queue to the left).
More informative article (Score:5, Informative)
There is next to no information in the first article... this one is much more informative:
http://www.theregister.co.uk/2009/05/19/lithium_oxygen_stair_battery/ [theregister.co.uk]
The concept (taking one of the reagents from air) is not new. There were zinc-air batteries for decades, and they are widely used. They have one of the highest energy densities of all types of commercially available batteries.
http://en.wikipedia.org/wiki/Zinc-air_battery [wikipedia.org]
Seems like four years ago somebody even figured out how to make them electrically rechargeable (before that, the usual method of recharge was to replace the zinc plates and remove oxide waste, which was facilitated by cell design).
http://www.eetimes.com/news/semi/showArticle.jhtml?articleID=164903727 [eetimes.com]
However, if those new batteries use carbon instead of zinc, they might have a higher theoretical upper bound on energy density. It looks like they're using graphite-lithium intercalate for the negative electrode (a standard thing), and the positive electrode is essentially a combined catalyst/adsorbent for Li2O2 which forms during electricity generation.
CnLi ---> Li+ + Cn + e
2Li+ + 2e + O2 --cat.-> Li2O2
Note that the first article is rather bogus: O2 does not "recharge" the battery, it is only a reagent.
I'm not familiar with the cost breakdown for the components of Li-ion batteries, but lithium seems like a major contributor, so this might not be much cheaper than the traditional Li-ion.
Re: (Score:3, Funny)
So you're saying that a better battery technology involving dilithium comes out, just coincidentally, the same month as a new Star Trek movie?
Damn it I hate viral marketing.
Re-agent!? (Score:3, Funny)
O, not CO2? (Score:3, Interesting)
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Entropy is not a law that can or cannot be violated. It is a property of a system, like enthalpy, temperature, or pressure.
If you had said that the Second Law of Thermodynamics would be violated, then you might have a point.
Not first, not by 150 years or so (Score:3, Interesting)
If you go down to your local 24-hour CVS MegaStore, peer at the hearing-aid battery end cap display, you'll see about 24 different kinds of "hearing air-cells". Cells where you remove a little cover over some breathing air holes to activate them.
Air-reacting cells have been around a long time.
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Well, normal cars already do run on oxygen, just like you and I (that's why you have to change your air filter once in a while!) so this wouldn't make that any worse - as far as I know, extra CO2 rather than a shortage of oxygen is our problem, which it doesn't seem this would solve.
I wouldn't feel too guilty about using it in a laptop or flashlight though.
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These take in oxygen when they run and give off oxygen when they recharge. The only issues, then, are the energy to make the batteries and the energy to recharge them. That comes from somewhere, and likely much of it is from burning fossil fuels. At least it'd be at central fossil fuel plants with scrubbers and carbon sequestration, which can't be done properly in a car.
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You seriously underestimate the amount of oxygen in the Earth's atmosphere. Even massive forest fires do not change the global concentration of oxygen enough for anyone to notice.
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How long which will last? The batteries or the geeks?
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