Lithium batteries going wrong

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Don
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Lithium batteries going wrong

Some chemists at Cambridge University have come up with a theory as to why lithium cells sometimes go boom. I can't get access to the linked article from here, but may be able to at work.

 

http://www.theregister.co.uk/2010/05/18/exploding_batteries/

 

Here's the abstract from:

http://www.nature.com/nmat/journal/vaop/ncurrent/abs/nmat2764.html

 

Lithium metal has the highest volumetric and gravimetric energy density of all negative-electrode materials when used as an electrode material in a lithium rechargeable battery. However, the formation of lithium dendrites and/or ‘moss’ on the metal electrode surface can lead to short circuits following several electrochemical charge–discharge cycles, particularly at high rates, rendering this class of batteries potentially unsafe and unusable owing to the risk of fire and explosion. Many recent investigations have focused on the development of methods to prevent moss/dendrite formation. In parallel, it is important to quantify Li-moss formation, to identify the conditions under which it forms. Although optical and electron microscopy can visually monitor the morphology of the lithium-electrode surface and hence the moss formation, such methods are not well suited for quantitative studies. Here we report the use of in situ NMR spectroscopy, to provide time-resolved, quantitative information about the nature of the metallic lithium deposited on lithium-metal electrodes.


 

 

The numbers from my light tests are always to be found here.

https://spreadsheets.google.com/ccc?key=0ApkFM37n_QnRdDU5MDNzOURjYllmZHI...

Edited by: Don on 05/18/2010 - 14:25
alfreddajero
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Now that was a good read........

With Darkness, there will always be Light.

 

 

Don
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My first degree was in chemistry which is why I'd like to see the full paper. Even if I am nearly 30 years out of date (Graduated 1982) I could probably figure it out. The Register is usually a good read and they don't mess up techincal stuff the way many journalists do.

 

What the abstract says, in summary, is that they used an MRI machine to directly image the formation of lithium metal inside the cell. Metallic lithium formation inside a cell is bad.

 

Anyone who's worked with datacentre installations of computers will have stories about zinc dendrites (whiskers) doing terrible things too. These come from the galvanised steel that most of the metalwork is made from.

 

The numbers from my light tests are always to be found here.

https://spreadsheets.google.com/ccc?key=0ApkFM37n_QnRdDU5MDNzOURjYllmZHI...

Nautic
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Very interresting. But have they a solution to how we avoid the problem, except using protected batteries of cource?

Cheap quality is good - Expensive crap isn´t

Don
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Once they have a better idea of how the lithium metal dendrites get formed, it may be possible to change the formulation in such a way as to minimise their appearance and growth such that the lithium cobalt oxide chemistry (which is the highest capacity available at present) is considerably safer than at present. Meanwhile the trick is not to abuse them - don't try to charge them if they have dropped below about 2.5V after resting, don't batter them and don't charge them at high currents.

 

The numbers from my light tests are always to be found here.

https://spreadsheets.google.com/ccc?key=0ApkFM37n_QnRdDU5MDNzOURjYllmZHI...

Nautic
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I have a dead lithium battery for my camera. Shows 0 volt. I have tried the supplied charger. No luck.

I have also tried with a laboratory power supply (nothing exploded), but still no result.

Any way to revive it?

Cheap quality is good - Expensive crap isn´t

Don
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Probably not. Sily question, it is a rechargeable cell/battery?

 

Assuming it has a nominal voltage of 3.7 - 4V it is a single lithium ion cell - if it is 7.2-8 it is a two cell battery.

 

Try putting about 20mA into it (With the battery in a fireproof container) at a bit over the rated voltage (nominal voltage 3.6V I'd not go above 5V, nominal voltage 7.2V 9-10V maximum) - just ramp up the voltage till you see 20mA flowing. Let it run for a few hours. The battery may well have an internal protection circuit that permanently shuts it down for safety. It might be possible to bypass the protection circuit but it is there for a good reason. If it is reading 0 volts I'd suspect a protection circuit has shut it down. Probably because one or more cells is in a bad way.

 

The numbers from my light tests are always to be found here.

https://spreadsheets.google.com/ccc?key=0ApkFM37n_QnRdDU5MDNzOURjYllmZHI...

Nautic
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Thanks. Its a 3,6 volt Li-on to a Panasonic Camera. It said 3500 mAh. The stock battery is 900 mAh.

I bought it recently in Singapore. The high capasity wondered me, but as it would be nice with that,

I bought it. Maybe I have been cheated. He knew I was from Europe, so I probably wouldn´t be back

at the double to wring my hands around his neck when I found out.

 

It sat on the camera for some time, so I think your right about the protection.

 

I may try your solution some day. Outside wearing full protection suit!!

Cheap quality is good - Expensive crap isn´t

Don
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That's a pain about the battery. Probably toast - the mAh rating does sound suspicious unless it is 4x the size of the official one. If it wasn't expensive I'd just toss it.

 

The numbers from my light tests are always to be found here.

https://spreadsheets.google.com/ccc?key=0ApkFM37n_QnRdDU5MDNzOURjYllmZHI...

Nautic
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I´ll toss it. He can just wait to I get back to Singapore some day!

Cheap quality is good - Expensive crap isn´t

Nil Einne
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Don are you still for the full text? I could help if you are...

Don
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If you could please, I'd really appreciate it. My academic account gets me biomedical stuff and sociological stuff, not interesting stuff.

 

The numbers from my light tests are always to be found here.

https://spreadsheets.google.com/ccc?key=0ApkFM37n_QnRdDU5MDNzOURjYllmZHI...

Nil Einne
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Slightly OT but hey since this concerns li-ions exploding, if anyone missed it, someone had the unfortunate experience of batteries exploding inside their flashlight as reported in a German site http://www.messerforum.net/showthread.php?t=86475 and described/discussed on CPF http://www.candlepowerforums.com/vb/showthread.php?t=280909

 

From an automatic translation "My right thumb was open to the bone"

 

Scary stuff!

alfreddajero
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Oh man yes it is......i always tell new comers that come into this hobby and really want to go lithium because of its energy density, lightness of the cell, and of course the power the cell puts out to please read up on it.  I keep my cells in a safe place away from the kids, and the lights with lith rechargeables  in it are safely put up til needed.  Treat the cells with care and always use a dmm to check the voltage before you put the cells on the charger and to check after it has charged, doing this all the time will become second nature.

With Darkness, there will always be Light.

 

 

brted
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Wow. People warn everyone like crazy about li-ion batteries, but I'm surprised how few bad incidents like this actually happen. I wonder if there was a short or he had a battery reversed? I had a spring on the back of the driver come loose one time and it shorted the battery + and - which would have caused a fire pretty quickly I think if I had been using the flashlight, but fortunately I was measuring current and realized something was wrong (it was my fault the spring came loose; I'm a lot more careful now). Now when I have a light that doesn't come on when I press the button, I don't fiddle around with the switch (except maybe to turn it off), I take the tailcap off immediately and see what's wrong.

alfreddajero
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I have seen lipo packs used at the rc tracks, all you see is your ride on fire going into the straight.  Not funny at all for the owner but it was a sight to see though.  And havent you noticed that they were mostly talking about one brand, for me it could happen to any cells that the user had around be it AW's etc. 

With Darkness, there will always be Light.

 

 

sixty545
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Four days ago I received a pack of 14500 and a pack of 16340 protected flame batteries from DX after reading good about them on this site. The two 14500 and one of the 16340 charged OK to 4.17 V but the last 16340 had a voltage of zero and made my charger (Cytac, the same as TR001) go bananas with flickerings leds. I then put the battery on a power supply at 100 mA and could watch the voltage slowly rising to over 3 Volt. The Cytac was now happy with it and charged it to the normal 4,17V.

Now, after resting 4 days, the 14500 are 4.15V, the "good" 16340 is only 4.08V and the "bad" 16340 is 4,02V.

I now wonder which hazard I'm going into by using those two 16340 in my coming 16340 flashlight.

fran82
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Caution! throw that 16340 to the garbage! (the one received at 0 volts) and ask for replacement. That battery can become in "unstable condition" and explode, fire your house, etc.......

This post/thread "may" contain referrals, a little contribution I "earn" in form of points ONLY if you buy the item. The purpose is to redeem items using the points and then making reviews of them in the forums to shar

Budgeteer
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I would toss it without feeling bad at all.

kragmutt wrote:

They're gonna send you a green redcat with a black LED.

SPAMBOT
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Save the cell but mark it so that you can keep track of it. Also, do not use cells of different state (charge, wear, age, manufacture etc) together in a series configuration.

Now with 100% all natural asbestos!

newbie74
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Hello all,

has there ever been a case of a single cell explosion?

 

I only use protected cells and only single cell flashlights - but I must admit, sometimes I do not measure the voltages.

How risky is this?

 

Thanks a lot

Don
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newbie74 wrote:

has there ever been a case of a single cell explosion?

 

Only when something silly has been done like dead shorting it for a while. That said, I did accidentally do this. The cell leaked and was destroyed but there was no smoke or flames. Try hooking it up to a car battery charger set to 5 amps and you'll get it to blow - but that would likely make an NiMH leak violently at best too. You can make NiMH cells go bang - you just have to work hard to do it.

 

newbie74 wrote:

I only use protected cells and only single cell flashlights - but I must admit, sometimes I do not measure the voltages.

How risky is this?

 

Your chance of being killed by a dead fish dropped by a seagull while in the Sahara Desert is considerably higher. Single cell lights are safe enough. Most exciting stuff with lithium cells is when they are being overcharged or charged at too high a current. I would toss any lithium cell that was below 2.5V on standing for an hour or two. It will probably be safe, but it will have a small fraction of its original capacity. Anything that had been charged above 4.35V I would be happy to use but would not attempt ever to recharge it again. Some of the newer very high capacity 18650 cells are designed to be charged to this voltage - the Chinese stuff most of us buy emphatically is not.

 

The cells are cheap enough and my flesh isn't. In general to give the cell a chance to live beyond a few cycles it is best to keep discharge rates below twice the capacity unless the cell is specially designed for high discharge rates like the AW IMR cells or Sony's equivalent. So for a 2400mAh 18650 I'd not want to discharge it at more than 4.5-5A. I have had an unprotected 18650 provide 9A until flat, and recharged it several times. It didn't last a year but it didn't do anything exciting either - just stopped working.

 

The risk is pretty low, but not zero. I've never really given it a thought but I do pay attention to what voltage they are coming off the charger. Above 4.35V Bad Things are likely to happen.

 

All the dead lithium ion cells I've had have failed gracefully - they just wouldn't hold a charge any more. One of them actually showed a small negative voltage - I most certainly did not try to recharge that one.

 

For fun, we once connected a dead RCR123 across a 200A welder then turned it on. That stuffed something like three kilowatts into it.

Briefly.

 

Best to do this outdoors and I didn't think to bring a camera. 

Doing that to almost any other battery would have the same result but wouldn't have hot hydrogen fluoride and burning lithium metal as a door prize.

 

Almost everyone gets away with using and abusing lithium ion cells with no harm to themselves - not that I am recommending this - all that happens is that the life of the cell is drastically shortened. I would check voltages as a matter of course in multi-cell lights.

 

At least when they came off the charger.

 

And maybe occasionally in between charges.

 

But then there is no light I own that I would not be prepared to throw as far as possible and then run if I thought the cells in it were doing Bad Things.

 

The numbers from my light tests are always to be found here.

https://spreadsheets.google.com/ccc?key=0ApkFM37n_QnRdDU5MDNzOURjYllmZHI...

brted
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sixty545 wrote:

Four days ago I received a pack of 14500 and a pack of 16340 protected flame batteries from DX after reading good about them on this site. The two 14500 and one of the 16340 charged OK to 4.17 V but the last 16340 had a voltage of zero and made my charger (Cytac, the same as TR001) go bananas with flickerings leds.

Doesn't 0V just mean the the protection circuitry tripped? My understanding is you should be able to charge it and the circuitry will reset itself. Not sure why the charger wasn't happy with it though.

Don
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brted wrote:

sixty545 wrote:

Four days ago I received a pack of 14500 and a pack of 16340 protected flame batteries from DX after reading good about them on this site. The two 14500 and one of the 16340 charged OK to 4.17 V but the last 16340 had a voltage of zero and made my charger (Cytac, the same as TR001) go bananas with flickerings leds.

Doesn't 0V just mean the the protection circuitry tripped? My understanding is you should be able to charge it and the circuitry will reset itself. Not sure why the charger wasn't happy with it though.

 

My guess, and it is just a guess, is that once it had reset the protection circuit, it was still at a lower voltage than the charger was happy with applying any real current to.

 

This may be a higher voltage than i would consider it unsafe to recharge it from.

 

The numbers from my light tests are always to be found here.

https://spreadsheets.google.com/ccc?key=0ApkFM37n_QnRdDU5MDNzOURjYllmZHI...

newbie74
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Don,

thanks for the time you took writing that.

 

I was planning the give 2 cells as a gift and decided to check them. One was flat, so I removed the protection board and it showed 3.6V. More trouble to repair than to order a new one, so it got tossed (even though the thought of using it without protection crossed my mind.

 

I do not abuse the current draw (low mode most of the time) and recharge them long before they reach 3.7v, so I guess I'm not even abusing them, but your example was priceless.

 

sixty545
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brted wrote:

sixty545 wrote:

Four days ago I received a pack of 14500 and a pack of 16340 protected flame batteries from DX after reading good about them on this site. The two 14500 and one of the 16340 charged OK to 4.17 V but the last 16340 had a voltage of zero and made my charger (Cytac, the same as TR001) go bananas with flickerings leds.

Doesn't 0V just mean the the protection circuitry tripped? My understanding is you should be able to charge it and the circuitry will reset itself. Not sure why the charger wasn't happy with it though.

In fact, the battery was shorting the charger. It took a while at 100 mA in the power supply for the voltage to rise from zero to 3 V. Now, a few hours later, the self discharge has progressed so the cell voltage is now 3.98 V.

I suspect that is has internal dendrite formation or the protection circuit is draining it. In some weeks I expect the voltage to be almost zero again, so the battery is garbage. I will keep an eye on it.

agenthex
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Lithiums aren't nearly as fragile as some on CPF make them out to be (basically to promote the expensive ones their vendor sells). Those idiots are always going on about slight breaches over 4.2v, when the manufacturers themselves spec the batteries to  4.2+-0.05. Then they would turn around and recommend a PILA to charge 10440, at way over the current limit, which is by far the worse of the two possible indiscretions.

 

Using hobby chargers are also not as safe as some claim. Crappy DX chargers are shipped out to thousands and if people's house got burned down because of it, we would know about it. Hobby chargers require DIY rigs and mistakes there are going to be lot more likely than any mass manufactured item.

 

You'd probably want similar cells in a multi-cell config (and a sanity check before loading those) to prevent reverse charging, which is one of the "common" causes of failure. Protection is a good thing, because it's practical to save cells from overdischarge and can prevent shorts, so buy cells with it, but it's not a huge deal in buck drivers since those'll dim anyway to warn you of low capacity. Other than that, don't fret over it. You use a meter, so you're already ahead of most people.

 

Reading this makes you smarter: http://lesswrong.com/

Don
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agenthex wrote:

Lithiums aren't nearly as fragile as some on CPF make them out to be (basically to promote the expensive ones their vendor sells). Those idiots are always going on about slight breaches over 4.2v, when the manufacturers themselves spec the batteries to  4.2+-0.05. Then they would turn around and recommend a PILA to charge 10440, at way over the current limit, which is by far the worse of the two possible indiscretions.

 

Using hobby chargers are also not as safe as some claim. Crappy DX chargers are shipped out to thousands and if people's house got burned down because of it, we would know about it. Hobby chargers require DIY rigs and mistakes there are going to be lot more likely than any mass manufactured item.

 

You'd probably want similar cells in a multi-cell config (and a sanity check before loading those) to prevent reverse charging, which is one of the "common" causes of failure. Protection is a good thing, because it's practical to save cells from overdischarge and can prevent shorts, so buy cells with it, but it's not a huge deal in buck drivers since those'll dim anyway to warn you of low capacity. Other than that, don't fret over it. You use a meter, so you're already ahead of most people.

 

[AOL]

Me too

[/AOL] Smile

You got it!

 

Above 4.3V worry about it - as in toss the cells.

 

Below that.

 

Don't worry about it.

 

In single cell applications.

 

In multi cell devices,use the voltmeter. Or there is a small chance of losing fingers.

 

Your fingers.

 

Your choice....

 

The numbers from my light tests are always to be found here.

https://spreadsheets.google.com/ccc?key=0ApkFM37n_QnRdDU5MDNzOURjYllmZHI...

fishinfool
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Don wrote:

Your chance of being killed by a dead fish dropped by a seagull while in the Sahara Desert is considerably higher.

 

That's friggin' hilarious!  Laughing  Laughing  Laughing

Thanks for the laugh Don.

 

It is now my new sig.  Hope it's ok with you Don.

 

 

Don wrote:

"But as I said long ago, you are more likely to be killed by a dead fish dropped by a seagull in the Sahara Desert than by a lithium ion

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Man, I'm still laughing......must be the beer......but still.....Laughing

Don wrote:

"But as I said long ago, you are more likely to be killed by a dead fish dropped by a seagull in the Sahara Desert than by a lithium ion

agenthex
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You may want to edit it without the quote tags, because it's causing every thread you post in to lose its background.

Reading this makes you smarter: http://lesswrong.com/

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