'Air fuelled' battery tech invented in Scotland Boffins based in Scotland believe they're on the track of rechargeable batteries which could broach a barrel of whup-ass on any now in service - and even more advanced types in development. The new super batteries gain their advantage by absorbing atmospheric oxygen as they discharge, and giving it up again as they charge. …
From the decsription, it's not actually using up any oxygen, just using it temporarily to drive the reaction. The same amount of oxygen is recycled during the charge/discharge cycle.
In any case, most existing conventional subs charge their batteries while running on the surface using diesel motors where there's plenty of oxygen for the batteries.
why not use it in subs?
if the porous carbon is placed in water instead of open to the interior atmosphere of the sub it should work quite well. averages of oxygen in air and oxygen disolved in water are 20.9% and 14.6% by volume, the difference in performance could be made up by using a 'frilled' system much like a fishes gills to give maximum surface area contact with the surrounding water.
this would be safer than just sticking them in subs in 2 ways, submariners dont suffocate and no chance of explosion due to oxygen buildup (the oxygen being released directly to the ocean to dissolve once again in water)
paris - cause she KNOWS how to park a submarine
They could work assuming that the oxygen was released again and that the sub had been designed to work with this system.
Also, if the various gill-like systems people are trying to develop ever get finished you could use that to provide oxygen to the batteries while they're in use.
And the military would have no use for it on manned, oxygen-dependant subs as they've got lovely nuclear power to provide a safe, clean source of almost limitless power and various underwater bots to do their bidding.
> "On the other side of the coin, you wouldn't want to use STAIR batteries in some applications - for instance, propelling submarines underwater - as they'd tend to suck all the oxygen out of the hull atmosphere"
Besides, there's already enough oxygen thieves serving in Submarines .....
Yes, there's Oxygen in water, both as the water itself and dissolved into it as well. However, there's also water in water. And as far as I can reckon, submerging batteries into salt water just seems like a Bad Idea(TM).
Besides, why bother with this crap when you can just have a fission reactor and be done with it?
'Besides, why bother with this crap when you can just have a fission reactor and be done with it?'
Because reactors need pumps which make noise and make the submarine more vulnerable. Diesel electric submarines such as those deployed by the German and Swedish navies, run rings around nuclear subs.
Why bother with this instead of a fission reactor?
Well, fission reactors are large and heavy. This is not an insurmountable problem if you want to use the sub as a missile carrier, since those also tend to be on the somewhat larger side. But for a small recon/attack sub, a non-nuclear option might be beneficial. See also the German type 212 (e.g. <http://www.naval-technology.com/projects/type_212/>), which is using a 'conventional' fuel cell system to achieve this goal.
The competing technology for these batteries is not conventional lithium batteries, it is OTHER AIR BREATHING BATTERIES like zinc oxide. Military zinc oxide batteries have an energy density of 350 Wh/kg, as compared to these guys 3050 Wh/kg. So the increase in what they are really competing against is about x9 not x19.
I rather suspect that the pores in porous carbon might be a bit too big, and the size of O2 and H2O molecules too similar for this to be simple solution.
The other problem you would need to solve is what to put on the "dry" side of the filter. The partial pressure of O2 on the dry side would have to be (much) less than that on the wet side, but the filter would either have to be strong enough to resist the external pressure or you would need to equilibrate te dry side pressure to the external pressure. Oh, an you'd need to have a pretty large surface area to get O2 across at a useful rate (SA of human lungs is ~ that of a tennis court).
Once you've sorted out those minor niggles, I'm sure it will work very well.
Alternatively, why not use the battery to generate it's own O2 by electrolysing the sea water ?
"Diesel electric submarines such as those deployed by the German and Swedish navies, run rings around nuclear subs."
Diesel / Electric boats are quiet for a while. A short while. And then while they're recharging they are as noisy a fcuk.
Nukes (at least those without coolant pumps) are also very quiet. For months at a time. Out of the two I'd rather be on a nuke.
And, after being brought up in Leicester, I have already received higher doses of background radiation from the local granit, than I would get from a nuke boat if I lived in one for the rest of my life.
As did the hand-cranked subs of the US civil war, what with the human power and all. I can't see how taking up oxygen and then releasing it again would be so much an engineering challenge as taking up oxygen and releasing carbon dioxide, which is apparently already solved since diesel subs already exist.
As for flammability and explosiveness, flung any burning cigarettes into your local petrol station's pumping area lately? Yes, releasing oxygen while charging could be hazardous, but we perform tasks in hazardous scenarios all the time. Some care has to be taken to avoid releasing power with disastrous quickness no matter what your dense power source. Getting the power density of the batteries higher is exactly the point, so some care will be needed.
Not quite. Nuclear powered subs run rings around conventional diesel electric jobs.
However, a diesel electric sub submerged running on electric at low speed is dead quiet. So quiet that they've known to sneak past US carrier battlegroups unnoticed.
Also, a diesel electric sub can call a full stop and shut absolutely everything down making it practically impossible to detect. If it can sit near the bottom of the sea/ocean where they are, even active sonar will be unlikely to pick them up.
Add titanium (alloy) constructions with minimal ferromagnetic components and even MAD detection could fail. Not that Magnetic Anomaly Detectors are much of an issue anyways, they tend to be extremely short ranged.
3050 Wh/kg is almost 11MJ/kg. A Tesla Roadster does 2.53km/MJ or 27.7km/kg of battery. (actually you could go further as you are not lugging around a hefty Li-ion battery). For comparison a Honda Civic VX (51mpg=21.7km/l) goes 29.5km/kg of fuel.
A 1kg battery would handle my most common round trip journeys. Charging time is not that important, as it would be practical to swap a pair of 10kg batteries every four hours on long journeys.
All figures came from: http://www.stanford.edu/group/greendorm/participate/cee124/TeslaReading.pdf and http://www.mgkscotland.co.uk/lift_drive/health&safety/lifting.htm
Make a porous shell a tiny bit hydrophobic (and double the surface as compared to the aerial version) and you're good to go. Pressure difference is not going to be a huge problem, as you can increase the inner pressure as much as you want. And I don't know about the specifics of the battery, but I don't suppose the inside is dry...
As for electrolysis of water using the battery's own power, erm, are you joking or a 5th grader?
"If STAIR ever goes mainstream, users may need to be a little careful about battery charging (at least in large applications like electric vehicles). A build-up of oxygen in a confined space is a significant fire and explosion risk."
Isn't this also the case with conventional lead-acid batteries that can give off hydrogen while charging?
""The competing technology for these batteries is not conventional lithium batteries, it is OTHER AIR BREATHING BATTERIES like zinc oxide. Military zinc oxide batteries have an energy density of 350 Wh/kg, as compared to these guys 3050 Wh/kg. So the increase in what they are really competing against is about x9 not x19.""
No.
I *presume* you mean Zinc Air batteries like the US army BA-8140/U, mfg by Arotech, built from cells from "Electric Fuel." Which is listed as having an energy density of 350 Wh/kg.
It's also listed as being a *primary* cell. It is not rechargeable, unless you want to scoop out the ZnO formed once switched on. With 1 exception I know of (the UK submersible UAV mentioned in previous Reg stories) EV applications require secondary cells. The other one I have heard of is the Silver/Air cell, which also uses Zinc and is also a primary cell. If you know of another air/metal secondary cell chemistry please say so.
Zinc-oxide/air batteries are primary cells and not rechargeable. They're one-shot unlike the STAIR rechargeable battery described in the article. It's still blue-sky and may not come to anything; there are a lot of factors to be investigated like maximum charge and discharge rates, charging efficiency, disposal of dead batteries at end-of-use, life cycle durability etc. but that's what R&D is for.
Exactly how is an electric cooling pump significant noise-wise when compared to a humungous sub-propelling electric motor with a sodding great propellor on the end?
Also: Range. The need to surface. The need to refuel at sea. Smaller size. etc. etc. etc.
The one and only advantage that Diesel/Electric subs have over nuclear* is that they're a damned sight cheaper to buy.
*Unless you're one of those anti-nucular evryfing types of course, in which case there are two.
Remember the military operations in the mediterranean, and the patrols in the Gibraltar straits a few years ago?
One of the Norwegian subs had been in the mediterranean, spying on weapons smugglers for a tour, and when they returned home, the captain didn't want to bother with the blocade in the straits, so went through submerged.
There were patrol craft on the surface, running all their sonar and whatnot, but no one ever spotted the sub going past.
At speeds of less than 5Knots, there's very little that can track a diesel electric unless you use 'active' sonar (sends out soundwaves), and even then you have to 'paint the target' correctly.
And if there's a 'boundary layer'(different temperatures because of underwater currents) not even active sonar works.
There is no Chemistry.
There is Environment, Biology, Space, Rise of the Machines and Physics. I guess Physics is the nearest to Chemistry. Besides, they are close relatives. If you want a Chemistry section then we better have Mathematics, Electrical Engineering, Mechanical Engineering etc.
People commenting about lighting cigarettes around batteries might care to remember the standard Haynes manual guidance about lead-acid batteries, specifically the part about hydrogen gas being given off when the battery is charging. You don't see too many accident reports due to mechanics smoking cigarettes around the car battery, most likely because (a) there isn't much gas released, (b) you'd need to actually drop the cigarette into the battery for it to have much of a chance of doing anything, and (c) it's clear to most people that smoking in an garage environment that contains petrol, oily rags and other flammable substances is not a move that ensures a long and happy career.
"On the other side of the coin, you wouldn't want to use STAIR batteries in some applications - for instance, propelling submarines underwater - as they'd tend to suck all the oxygen out of the hull atmosphere, with fatal results for any humans therein"
why not use the O2 in the sea water, cant this tech use that just as effectively ?
and why dont we ever hear of these advanced things after they are available and on the shelf, it seems we hear lots of good idea's that are shown to work in the lab, but nothing ever seems to make it to end users asda shops for bulk purchase and thats a shame....
i want mini wind, CO2 cat converters, solar, and this long term power storage in a small portabale box, that can power my wireless 11n, LCD's and mini PC motherboards for a 12 hour night, thats all.
i want to be able to buy these self contained low cost boxs in my local (specialist) shops, say on a month and add them together in a generic connected way, and to slowly build up my long term power storage over a few months and years, justas i upgrade my PCs today, one section at a time, getting more powerful as time goes on.
i dont want to have to shell out a mass of cash at the onset , or run the whole house etc, i dont want to feed any excess back into the grid to start with if ever, or run an electric car.
i just want small ,simple self contained units that i can run the odd PC and related low power wireless kit, why cant i but that today ?, and why , if these so called proof of concept lab tests really work, havent tesco etc sone a deal for mass production...
a secondary battery with excellent energy density and non-toxic emissions when charging.
Caveat: needs to have adequate air flow when in use and adequate ventilation when charging - and one presumes that O2 absorbtion/release will be at a rate in proportion to its dis/charge rate so that should not be problematic in applications such as electric vehicles with the battery packs mounted outside the driver/passenger cabin (such as in the boot ("trunk") or under the bonnet ("hood") or in the chassis)
Better energy density = more "oomph" (speed/range) for the same weight of batteries or the same speed and/or range with less overall weight - allowing for a wider range of vehicles.
now all we have to do is find a means of generating the electricity we'll need...
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