Dunno how I cam eon to it, but somebdy mentioned fuel cells, and it seems they suck for small power (like charging ipads) applications. Anyways I started to google, and found that magnesium gives much more power when used with salt water than hydrogen fuel cells, found this:
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Of course I do not need YAO rechargable, but was wondering if I could make my own high power battery. Magnesium sheet is easy to get, and cheap:
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the other electrode could be anything that conducts I think? Would be nice in the boonies, but especially useful on a boat in the ocean if you need power for something, plenty of salty water around.
My chemistry is a bit rusty, been too long, but maybe somebody here knows how to calculate the Ah I can get from dissolving a 1 x 120 x 100mm magnesium sheet in salt (sea) water. Magnesium pads are also used on the outside of boats to prevent corrosion, electrolysis (the magnesium goes, the steel stays).
From the first ebay link it seems it should be a lot of Ah, why is this not used more often?
Search on battery chemistry. I suspect that you have the makings of a fun hobby project or science demonstration, but not a practical product.
There are batteries out there with replaceable electrodes, but they're very much specialty items. Batteries essentially work by corrosion, with the plates getting oxidized and reduced (respectively) and the reaction products going into solution in the electrolyte.
Good batteries have to work in such a way that this corrosion only happens when the battery is supplying power -- otherwise the battery will be discharged from just sitting around. (This is, in fact, self-discharge, and just about every battery does it anyway: it's just that the good ones do it slower).
Good secondary (i.e., rechargable) cells work in such a way that if you pump energy _into_ them the corrosion is reversed, and the original electrode materials plate back onto the electrodes.
So you need to find a combination of anode material, cathode material, and electrolyte that'll actually deliver energy, won't spontaneously corrode (or explode), poison you, polymerize, eat through any practical case material, evaporate, freeze, etc.
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Tim Wescott
Wescott Design Services
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Magnesium exposed to oxygen or water oxidises to non-conductive (and protective) magnesium oxide, much as aluminium does. Making it work as battery cathode calls for exotic and expensive electrolytes.
If you want to go to that kind of trouble lithium is lighter (atomic mass 6.94 versus 23.305 for magnesium) - if not quite a electronegative
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so you store rather more energy per unit mass in lithium electrodes, which is why the shops are full of lithium-ion batteries.
On a sunny day (Fri, 23 Jan 2015 17:56:45 -0800 (PST)) it happened Bill Sloman wrote in :
Well, I was hoping you would provide the math I wanted. Anyways before falling asleep I remembered (now that was long time ago when I discovered cold fusion, way before Pons & Fleischman no not kidding see my posting in sci.physics), anyways long ago I did electrolysis experiments, and I think I need to use 'moles' (ar'nt those animals digging tunnels underground?) and see how many electrons come free in that reaction you mentioned (did you?), and then assume some internal resistance and load (depends on battery construction), and then use the definition of Ampere and we have the answer, probably different from 42 ..
Anyways if you bother to google you will see it works quite well in spite of your objections:
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My chemistry right?
Anyways I ordered one of those magnesium sheets from ebay, so maybe I will roll it up with some metal foil, maybe even alu foil, as I have that in the kitchen, and use some salt water soaked coffee filter paper or maybe a sponge, or maybe a totally different construction, seem like fun.
You DID notice you can buy a 151 Wh device on ebay for 29.99 $ (now about 29.99 Euro) yes?
You didn't understand that it wasn't just mathematical insight that you lacked.
And cold fusion now powers western civilisation? I met Fleischman when he was a professor of electrochemistry at Southampton, back when I was a post-doc there in 1971/72.
He was a perfectly respectable academic back then - back before he'd been mouse-trapped into shooting his mouth off to the press before all the experimental evidence made sense (which it still doesn't).
Homonym.
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Why bother? If the electrode is going to corrode/self-discharge within a couple of days, the amount of energy that it might deliver in the meantime isn't all that interesting.
Beats me. How long does it keep on working as a battery?
No. Ebay isn't exactly a reliable source, so I've been there only for one-off requirements.
There's a concept you may need to understand - "bankrupt stock" - which refers to stuff that was owned by somebody who went bankrupt, and is subsequently sold by the bailiffs for what they can get for it - sometimes on ebay.
You need to do some reading-up on the latest and greatest things in chemistry:
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Actually I am not looking for a rechargable at all (have plenty of those), but for something you can activate 'on the wa'y, especially at sea where there is plenty of water and salt (with magnesium in it actually). I am a bit sad you neither was able -, or willing to publish the reaction or calculate the Watt-hours from a given weight -, or volume of magnesium. You being the only Dr in chemistry on this forum... ;-)
Radiosondes use Water Activated Batteries. I used to buy surplus Radiosondes when I was a kid. The mechanical aneroid barometer sender was a beautiful mechanism to learn from.
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VaiSala's MSDS:
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They are Magnesium-Copper primary cells. They do use an electrolyte paste.
RadioSonde batteries get hot. Once activated, they are going, and irrespective of load, the reaction runs forward. At least the ones I activated did that. There are a few on Ebay from time to time.
The general consensus was that he didn't. He does seem to have found something odd going on, but it doesn't seem to have been cold fusion, or anything remotely useful.
"Air batteries" would seem to fit the bill.
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I charge more per hour for hack-work than you can afford. In fact it's not the kind of calculation that needs a Ph.D. to do it - your nearest university should have a few graduate students who'd be glad to take your money and give you an answer.
Even they would probably warn you that there's not a lot of point in calculating the results of the reaction you'd like to happen - as opposed to the results of the reactions that actually would happen in the real world.
Be grateful that I've told you not to waste your time, and neglected to charge you for the service.
Magnesium can provide two electrons to the current flow, while lithium can only provide one.
Charge time for magnesium is also faster than Lithium:
"Magnesium To Replace Lithium-ion Batteries Soon"
"Rechargeable magnesium battery: Current status and key challenges for the future"
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Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
That doesn't beat out a 6.94 versus 23.305 atomic weight ratio. Magnesium does seem to offer a volume advantage though not a large one, but the additional volume of the other components of the cell means that this is unlikely to be decisive.
That depends on your cell chemistry.
Academics pushing their new cell construction technique. They may even be right, but Jan probably can't access their work.
More academics, talking about what might be possible after we've spent a lot more money on developing new electrode structures and new electrolytes.
As I misunderstand it, much of the weight of a practical battery is structural, and not involved in the actual chemistry. For example, the stainless steel jacket of most cells just holds it all together.
Incidentally, I forgot to mumble something about magnesium NOT forming dendrites, which is the major failure mode of today's batteries. Magnesium is also cheaper than lithium.
True. If charge time were the prime consideration, we would be working on quantum dot batteries:
You didn't read the article. It's by investors for investors interested in energy futures. No academics required. Just a healthy fear of having oil prices drop even further inspiring a move to something potentially more profitable. Just follow the money.
More academics. Check with your favorite university for a list of spinoffs and licensed companies using the results of their research. Perhaps your opinion of academics might change. For example, MIT claims 25,000 active spinoff companies since 1865. Here's the current list for the media lab: Lincoln Lab:
Moving away from academia, we have Toyota, which announced a magnesium-sulfur (or sulfate) battery development project in 2011, and then went into stealth mode, probably to avoid conflicting with their joint venture with Tesla Motors. Some rather skeptical speculation: I have no idea what Toyota is actually doing, but it's just possible that they might come up with something useful that doesn't require academics or government research funding.
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
protective) magnesium oxide, much as aluminium does. Making it work as batt ery cathode calls for exotic and expensive electrolytes.
mass
m does seem to offer a volume advantage though not a large one, but the add itional volume of the other components of the cell means that this is unlik ely to be decisive.
That depends a lot on how big the battery is.
Dendrite formation is one of the complications of electrolyte design/select ion/development. I don't think that there's anything in the properties of a lithium atom or a magnesium atom that makes dendrites more or less likely.
Perhaps.
e right, but Jan probably can't access their work.
In other words written by people who don't understand much about what's goi ng on for people who understand less.
Academics understand what turns on potential investors rather better than t he potential investors understand the science that they are being sold.
lot more money on developing new electrode structures and new electrolytes .
So what? I worked in Cambridge when academic spin-offs got popular there - Silicon Fen - and the work I did on voltage contrast was driven by Graham P lows, who invented the technique around 1966 when working as a graduate stu dent in Charles Oately's famous scanning electron microscope lab (which gra duated a lot of very successful Ph.D.s, most of them more successful than G raham).
In the early 1980's Graham introduced the world's first electron microscope specifically designed for voltage contrast work - he called it an electron beam tester - and he had the market to himself for a couple of years.
Sadly, he wanted a machine that was easy to sell, rather than reliable in u se, and as soon as the engineer that he'd irritated into going to work for Fairchild/Schlumberger got a better machine onto the market for Schlumberge r, Graham found it impossible to sell any more of his machines, and folded his spin-off after he shipped the last of his two year order book.
There's nothing magical about generating lots of spin-off. The number that was still making money ten years after they started up would be more intere sting.
Toyota is big enough to fund it's own blue skies research. They'll hire aca demic to do some of the research - academic's are trained to be good at blu es skies research, though they are also trained to present their results a s positively as possible, and to do the research as cheaply as possible, wh ich can sometimes lead them to make bad choices when "commercialisisng" wha t they think they've discovered.
On a sunny day (Sat, 24 Jan 2015 06:20:53 -0800 (PST)) it happened Bill Sloman wrote in :
Well, again I dunno, up until now 3 universities checked on it and say yes it works. But as he releases no exact description how do I know? I did some basic math on the e-cat website and concluded I should stay with my current electricity provider. The e-cat has extremely high temperatures, I never had those that high. IIRC he sold it to some 'merrican company. so something should go into production some day, unless they just play speculation, get investor money etc.
There also was a positive experiment in Japan with a different system, but all went quiet after that.
I am a bit surprised that you, who are such a strong religious believer in big oil countering the glow ball worming scene, do not see their hand here, but dismiss it, as any ignoramus (its witchcraft duh) what is really being done
You are blowing smoke.
I see you snipped the link I gave to that rechargeable magnesium based design published in nature.
Billy I know you're Ferry Old. And still struggling to understand -, and wear Bax Sandals. But did you ever make a usable contribution here?
If cold fusion worked, somebody would be making serious money out of it by now. They aren't. The effect was originally reported in 1989. A quarter of a century is long enough to justify fairly comprehensive skepticism.
th my current electricity provider.
oduction some day,
t all went quiet after that.
n
aft > duh) what is really being done.
Jan is surprised that few other people are as gullible as he is.
se),
re there is plenty of water and salt (with magnesium in
Wikipedia might be but zinc-air batteries have been around for a while. Far nell stocks hearing-aid-sized examples
ion or > calculate the Watt-hours from a given weight -,
ot
d to > >take your money and give you an answer.
sign published in Nature.
If you want a battery, you want a link to place that sells them, not a link to a paper that describes how you might build one if you had a few million to invest in working out how to reduce that particular idea to practice.
72 isn't old - unless you work in Human Factors/Personnel for a Dutch firm. Someone got a Ph.D. a Nijmegen last year for a study of creeps like that i n the Randstadt, every last one of whom seemed to think that their job desc ription still included clauses about not hiring anybody over 45 and persuad ing everybody over 55 that they ought to take early retirement. The Dutch g overnment is busy trying to get people to retire later and has been for a f ew years now, but the message has yet to make it into the personnel departm ents.
You'd have to ask, since you couldn't recognise one without help.
I wouldn't ask you to express an opinion on a Ph.D. thesis in any technical subject - you have imagination, but don't know very much.
The idea that any supervisor would put you onto a Ph.D. examining committee would be amusing, if I hadn't seem some thoroughly inept supervisors, and some exceedingly inept examiners reports - whose main interest seemed to be in getting the candidate to cite more of their work.
Well, yes. If I double the size of a battery in all three dimensions, I get 8 times the volume and 4 times the surface area. In other words, weight and volume increase faster than packaging. As the battery gets bigger and heavier, the outer jacket will need to become stronger and presumably heavier, which kinda ruins my nice neat ratios. Still, you could build a practical battery with flimsy internal cell packaging, and armor plated outer packaging, as in the Boeing Dreamliner LiCoO2 battery.
As I understand it, charging too fast is the major culprit with uneven porosity in the separator being a close second.. This is from 2002, but I suspect is still applicable:
"The separator with uniform permeability is essential for the long cycle life of a battery. Variations in permeability will result in uneven current density distribution, which has been verified as the main reason for the formation of dendrite Li on the negative electrode."
The implication from both these papers is that dendrite formation can be reduced, but not eliminated in Lithium based batteries.
Please think again. This paper suggests otherwise:
Charge time isn't particularly critical for smartphone users, but is very important for electric vehicle design. For example, a very fast charge time will make the electric recharge station practical. For example:
"Ultra-fast charging batteries that can be 70% recharged in just two minutes" Titanium Dioxide nanotubes.
I prefer to pass judgment on the research reports, the results claimed or obtained, and the products produced. I do not waste time trying to judge the people.
During the 1990's, I did some work for a venture capitalist in evaluating some of the grand designs and dot.com proposals that he considered worthy of funding. I think I have a good handle on the requirements and the people involved. Let's just say that I think you'll be rather surprised at the technical qualifications of many VC's. If they're lacking in some area, they have available some rather impressive talent to advise them. Much as I'm tempted to engaged in a debate on the relative abilities of academia versus industry, I'll pass (this time). Suffice to say that I was hired because the VC's were not getting what they needed from the academics.
However, for the day trader and casual investor, you're probably correct. Academics do understand the technology better. The problem is that knowing the technology doesn't automagically guaranteed a profit. There are a few other parts of the puzzle, such as funding, team building, staffing, taxes, etc that require attention, where academics are not necessarily the best informed, and where even casual investors can easily spot a problem.
I should ask you the same question. What does your involvement in electron microscope development have anything to do with magnesium chemistry, it's technical viability, or it's financial possibilities?
I offered examples of academic spinoffs to counter your apparently poor opinion of academics. Quoting: "More academics, talking about what might be possible after we've spent a lot more money on developing new electrode structures and new electrolytes." This is actually quite correct and a good example of why almost every research report I've ever read ends with "more research is necessary". Better minds look at what academia has produced, and decide if its ready for exploitation. Not ready in the sense that all the details are understood, but ready for product development. Like engineers, one has to literally rip the research or product out of their hands in order to produce anything useful. Sure, there are always better electrode structures and electrolytes on the horizon. But that's not what makes money for investors. Sell batteries with todays available mediocre electrode structures and electrolytes is what started most of the spinoffs. The one's selling science fiction are only for gamblers.
That's going to be difficult because most of them fail at the same rate as most small businesses. The one's the get funded are often structured to be sold to a mega-corporation once they are able to produce something sellable. Others get clobbered for economic, not technical reasons, such as the large number of solar panel startups funded by the NSF, all of which floundered when panels from China started undercutting their prices.
It's being done at TRINA (Toyota Research Institute North America) in Michigan. There are certainly some academics involved, but from what I read, it kinda sounds like an industrial research venture.
Academics are NOT trained to present their results as positive as possible, or they wouldn't end their reports with "more research is necessary". They're trained to be fairly positive, but to introduce just enough doubt that continued research funding is necessary to produce anything useful.
I worked for a company (Granger Assoc) that had a division (Transmux) built completely on the research of one individual. The emphasis was on getting the product to market quickly and to spend whatever is necessary to get it done quickly. At one point, an entire PCB fab facility and staff was "rented" so that a few days could be cut off the delivery schedule. Once I was able to obtain a good overall picture of what was happening and why, I found no evidence of bad choices. I've worked on several other products with similar goals and methodology. Once the goals are established, and the needs justified, development money was not a major problem. A former academic accustomed to counting pennies will fail miserably in such an environment.
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
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