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Silicon As the New Lithium
hduff writes "While lithium-ion batteries offer better performance than lead-acid or ni-cad batteries, the supply of lithium is limited and the batteries can pose problems. Researchers at the Technion-Israel Institute are building a better battery with easily obtainable sand and air."
While new battery technology is very important in our current time, the sheer number of duplicate stories and borderline advertisement/marketing stories on Slashdot about these new batteries, WITH a combines lithium FUD scare at the same time no less, sours these stories.
Seconded. Does anyone else remember when Slashdot stories linked to journals and essays rather than blogs and press releases? Hopefully the click-through counts reflect the /. reader's ability to avoid anything with "blog" or "gadget" or perhaps these days even "google" in the URL.
Forget thrust, drag, lift and weight. Airplanes fly because of money.
And there is the fact that salt water has lithium. In fact, some startups are trying to extract it now. If the price goes high enough, it will be practical to extract lithium from the ocean.
Still in prototype (seems he might have only made one, and he tested it for 600 hours ). Not rechargable. More powerful than current hearing aid batteries. May be made rechargable in 10 years (how on earth do people estimate this stuff? How can you estimate how long it will take to do something no one has ever done? It might not even be possible). Rumors abound. If it works out it will be great, but don't hold your breath.
Still, it's kind of cool that you can make a battery out of sand.
Qxe4
Natrium is called SODIUM in English. (Not sure, but I think that English is the only language that does not use the word "natrium" for Na).
And it might not be able to form the components that you need for the battery (it's not pure lithium).
Read more here.
http://en.wikipedia.org/wiki/Lithium-ion_battery#Electrochemistry
Also, if it would work, sodium is much heavier than lithium.
Chile has half the world's lithium and they're gearing up to play hardball over it. This will hopefully deflate those plans.
The article does not help understand how it actually works, so I read around and went to the Technion-friends website.
Basically normal sand is Silicon-Dioxide. If you take pure silicon and build a battery from it, and expose the battery to air, the silicon will interact with the oxygen in the air. So the pure silicon will become silicon dioxide - sand. In the process, it releases energy.
The neat trick in the battery - is that they set it up so that the energy is released NOT as heat (which is the usual thing), but some of it as electricity. They do this with some kind of membrane that allows oxygen ions to flow through, but electrons must come the other way - hence an electric flow.
Like any innovation, will take some years to be fully researched and commercialized. Small batteries will probably come first, bigger ones (for cars) later. And how to recharge does not seem obvious - at least not from the description so far.
A lot of people above are skeptical - but really this kind of innovation is what science and engineering are all about. Innovation goes hand in hand with raising ever more questions; we should be used to that by now.
Really really cool. And smart. My hat off to the Israeli guys and their collaborators in USA & Japan.
I have read the original publication (doi:10.1016/j.elecom.2009.08.015) and cannot understand much of the (electro-)chemistry of it.
The electrode potential is strongly dependent on the doping of the silicon, which makes sense, but the I/V curve looks less than impressive. It's mostly a bad fuel cell, at the moment.
Also, the chemistry of the electrolyte is not clear to me. In principle the battery should work according to dissolution of Si from the anode, transport through the electrolyte (an ionic liquid with fluorine) and reaction with oxygen at the air cathode. The researchers claim that they observe a white deposit at the cathode, and that this deposit is SiO2.
Silicon-fluorine chemistry is quite complicated, IIRC, and I cannot for the life of me imagine transport of Si4+ ions in the electrolyte. Also, HF as such does not dissolve Si, but it need some strong acid to start the etching. How this phenomenon can happen in the ionic liquid is beyond me.
Also, in the introduction, the researchers claim that the battery has an "infinite shelf life", but then talk about corrosion currents in the paper. If there is corrosion (i.e. self discharge), then the shelf life is quite limited.
Cherry on top, they claim that SiO2 is easily reducible to reobtain Si. I am not familiar with silicon metallurgy, but I am not sure it is easy to do it electrochemically, let alone replate Si at the anode upon recharge.
On the plus side, they used metallurgical grade Si, which is dirt cheap when compared to semiconductor grade Si.
I would love for this to work, but at the moment the authors have omitted quite a bit of information. If I were the referee, I would have asked at least the questions above. Think of it, there is a corresponding author for a reason.
Disclaimer: I work in battery research, and I am hence jealous that they made it to the front page of Slashdot.
Not sure, but I think that English is the only language that does not use the word "natrium" for Na.
Natrium was the original Latin name for the element but it's Sodium in English http://en.wikipedia.org/wiki/Sodium, sodio in Italian http://it.wikipedia.org/wiki/Sodio, sodium in French http://fr.wikipedia.org/wiki/Sodium, sódio in Portuguese http://pt.wikipedia.org/wiki/S%C3%B3dio, sodio in Spanish http://es.wikipedia.org/wiki/Sodio and I stop here because I don't want to enter into languages I don't know.
Google gives 12,500,000 occurrences of Sodium and 730,000 of Natrium.
(sorry may be some confusion - a double post since the previous one inadvertently was anonymous)
To better understand how this works, I went to the Tehnion website.
Sand is actually Silicon-dioxide (combined silicon and oxygen). Pure silicon interacts with oxygen form the air to create sand. That's first-year normal chemistry. Usually such an interaction produces heat not electricity.
They built the battery from pure silicon, and the trick is that Oxygen from the air has to pass through a membrane to get to the silicon and oxidize it. The membrane will allow only oxygen ions through, so electrons have to flow the other way to match up with the ions and maintain overall neutrality. Hence you get a current instead of only heat.
Of course it will take some years to commercialize. Small applications will come first (small batteries), only later will we get big batteries (for cars?) and even later rechargeable stuff (if at all). I noticed many people are skeptical - but this is normal in science and engineering. Any real innovation raises new questions that must be answered. Kudos to the Israeli team, and their collaborators from USA & Japan.
Natrium is called SODIUM in English. (Not sure, but I think that English is the only language that does not use the word "natrium" for Na).
No, both are used very widely, actually: "Sodium" (from arabic suda: soda headache tablets) is used in most Romance and Slavic languages and "Natrium" (from ancient Egyptian natron: baking soda/soda ash) is used in Germanic languages and Hungarian/Serbocroatian, mostly due to the influence of Berzelius (who was a Swede).
Actually at the moment things are going from green to desert. Desertification is a major problem around the world, including Africa and China, where arable land is being lost to the expansion of major deserts.
Aluminum is OK as a transmission medium, but it's not too good in end use applications. Turns out aluminum has a property called "cold flow", when you put it under pressure (like a screw or clamp terminal) the metal literally moves away and creates a loose connection which causes heat and often fire.
Next, greatly varying expansion/contraction properties make aluminum still more likely to work loose when terminated to a dissimilar metal like a lug or screw of brass, steel, etc..
Lastly, all aluminum has a coat of oxide that has high electrical resistance, and it reforms very quickly when it is cleaned off. Proper cleaning and antioxidant paste are critical to avoid failures in such home applications as the line dropping from the service weather head to the meter socket of a dwelling (a common application).
Once the circuits are in the walls of a dwelling you do not want aluminum because of the fire danger. While it has been used for mobile home wiring in the past during times of high copper prices, it is currently hard to insure one of those homes. If you DO have aluminum wire inside your walls you should be checking the torque (but don't over tighten) of every connection at six month intervals... forever...
To sum up, you only want aluminum where you can easily inspect and adjust any connections on a regular basis.
You have the right to remain sentient. If you give up the right to remain sentient, you will be elected to public office
Once the circuits are in the walls of a dwelling you do not want aluminum because of the fire danger. While it has been used for mobile home wiring in the past during times of high copper prices, it is currently hard to insure one of those homes. If you DO have aluminum wire inside your walls you should be checking the torque (but don't over tighten) of every connection at six month intervals... forever...
No, you retrofit it with copper ENDS (which attach with conductive epoxy) which don't have this problem. Guess what? We no longer use wires poked into holes in automotive applications anyway; all connectors are terminated somehow.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
Hmmm yes but no.
And yet it's being worked on.
e.g.
http://dx.doi.org/10.1016/j.elecom.2006.08.029
Deleted
All Li-ion batteries carry a fluorine containing electrolyte. In particular, LiPF6 is the salt used, dissolved in organic solvents. Plus a whole bunch of additives. The ideal salt would be a perchlorate, but being explosive it's not allowed.
I think you're confusing Chile with Bolivia. Chile has one of the strongest growing economy in South America and is a capitalistic country alright. Bolivia, on the other hand, has a socialist government and has been playing hardball with their lithium reserves.
Is'nt the world reserve of copper basically mined out?
According to Wikipedia, "total amount of copper on Earth is vast (around 1014 tons just in the top kilometer of Earth's crust, or about 5 million years worth at the current rate of extraction)". Of course only small fraction of this is available using _today's_ technology.
These alloys were cheaper if they are so easily obtainable, but I think there's a reason behind the price of stainless steel, which could be simple scarcity or high production costs.
A cursory glance at Wiki Grandma tells me that stainless steel requires a chromium content of 10 percent or more. And of course we have a singular dominant reserve: chromium is mined primarily in South Africa, harboring half the world's mineable reserves.
Not only that, but stainless steel is an even worse conductor than plain vanilla steel, having a resistance that is more than 30 times higher.
I once heard that Emerson (motor maker) uses 10-20 percent of the worlds electrical copper. Motors are a huge user of copper. I work in electric vehicles, and when we pump 100kW through a motor we're losing some 1.6 percent to heat in the windings. Change that to aluminum and the losses will only increase - and then the cooling solution becomes more complex, the weight goes up, the range goes down. Then there are the previously mentioned issues with aluminum. And to the GGP, all the easy copper has been mined, but I believe there is still plenty available to meet the inceasing demand. If handled properly it can be easily recycled too.
Ahh, I thought 1014 tons didn't sound like much. The copy/paste was bad.
It's 10^14 tons. That's more like it!
Tom...
Not only is there lots of research being done about copper replacing aluminum, but this particular scientist has done some himself.
His faculty page
Stuff his group has done regarding copper
Although it looks like he has done stuff to do with corrosion, most of this is over my head... go go Physics Nerds!