What's Wrong With Lithium Ion Batteries?

An anonymous Coward writes "Lithium ion batteries short-circuit. They overheat. They burst into flames. The reasons behind the recent spate of problems with a technology invented by Sony more than a decade ago are complex and varied, making for one big engineering headache."

Comments

Some stuf I wrote on this a while ago

[Groo Wanderer]

http://www.theinquirer.net/?article=14417

I wrote that before batteries going boom was the latest fashion trend. The problem is simple, you have a lot of energy in a small area and people crying out for higher densities. If _ANYTHING_ goes wrong, you have a high likelihood for a lot of energy released in a short amount of time.

Couple this with reactive/flamable substance that make up batteries, and you have a lightshow. There is no magic to it all, simple physics. Lots of energy released around reactive things, you need both for a modern battery.

Some designs minimize the risk, none remove it. As always, nothing new under the sun.

                -Charlie

Re:Some stuf I wrote on this a while ago

[KiloByte]

Except, chemistry is nothing but a certain application of physics (-> full quote).

Re:Some stuf I wrote on this a while ago

[Anonymous Coward]

You cannot derive physical laws from mathematical theorems

This is a fairly recent (i.e. C19) viewpoint, reflecting changing understanding of what mathematics is. Neoplatonists such as Galileo and Kepler, and synthetic geometers adopting the classical style, would have been happy to tell you that mathematics is a perfect way of describing nature.

Then the axiomatisers, perhaps heralded by Leibniz (whose more philosophical discussions on notation etc were of less immediate influence than his calculus, even though one begat the other), decided that mathematics was nothing more than a set of rules for symbol manipulation. Hence, for example, the arguments over Euclid's parallel postulate being initially connected with the question of whether geometry is "true" in the sense that it represents physical space.

In essence, you are vacuously correct, because today, mathematics without choosing some axiom system cannot do anything - it is merely an acceptance of "logic" without any definitions or rules to work from. But if we choose our axiom system to incorporate sufficient fundamental laws of physics, then physics becomes a branch of mathematics; just as if we choose our axiom system to be Euclid's definitions and postulates, Euclidean geometry becomes a branch of mathematics.

Re:Some stuf I wrote on this a while ago

[Goaway]

But if we choose our axiom system to incorporate sufficient fundamental laws of physics... In other words, if you add physics, then you end up with physics. A tautology, pretty much.

Article text

[Anonymous Coward]

What's Wrong With Lithium-Ion Batteries?

The announcement last month that 46 million Nokia-branded lithium-ion (Li-ion) batteries made by Matsushita Battery Industrial could potentially short circuit and overheat was just the latest in a spate of product advisories and recalls of the technology over the past two years.

But it's not as if Li-ion batteries are at the early point in their life cycle when you would expect these sorts of problems to crop up. Sony invented the technology back in 1990. So why is it failing now?

The theories behind the technology's recent spotty performance are complex and varied, which makes fixing the problem a perplexing engineering challenge.

A Constantly Evolving Technology

"You can't really say that for the first ten years the battery makers got it right and now they're screwing it up," says Jim Miller, Manager of Argonne National Lab's Electrochemical Technology Program. Funded by the U.S. Department of Energy, his group's research is directed at developing new materials for Li-ion batteries and addressing some of the major issues in scaling up the technology.

Miller points out that Li-ion battery technology is not just a single design or composition, but rather it's an entire family of chemistries that is constantly evolving. "When Sony invented it in 1990, it was lithium cobalt oxide. But cobalt is expensive and so engineers started replacing it with nickel, which costs less. And then as time went on engineers found that they could substitute cheaper nickel manganese alloys for the nickel."

Cost reduction isn't the only driving force behind the evolutionary march of Li-ion batteries. The desire to extend battery life, achieve higher energy densities and faster charging times, and improve reliability has led to a constant tinkering of the technology. Energy densities are double what they were five years ago, for example, and new surface coatings are being applied to make the batteries more stable and reduce their reactivity rates.

Ever-Increasing Demands, More Trade-offs

The trade-offs inherent in these often mutually exclusive goals make for a diabolical design challenge: You can make a Li-ion battery that has high performance, for example, but the trade-off is a shorter life. And as every design engineer knows, making the right trade-offs and getting everything right takes time, experience, and a bit of finesse.

"A problem doesn't necessarily pop up during the first generation of cells," says Miller. "Things may look fine in the lab and then when you go to production you find that the technology behaves in a slightly different way, which means things can and do go wrong."

Something certainly went wrong at Sony last year, resulting in the recall of millions of its Li-ion laptop batteries. As for what exactly led to the short-circuiting problem that posed a risk of fire and in one case caused a Dell notebook to burst into flames, Sony Spokesperson Rick Clancy says that there were different conclusions at different levels.

"When you produce lithium ion batteries, the objective is to either have zero metal contaminants or at least as few of them as possible and surround them by a protective shell or layer so that they cannot penetrate the separator," explains Clancy. The separator in a Li-ion battery keeps the anodes and cathodes from touching each other and causing a short circuit.

Clancy says that Sony engineers discovered that there was a greater frequency of these metal particles escaping from one part of the cell and entering the other part. They've addressed the issue at a product level by designing in a stronger lining, he notes.

But there were other

They only started doing this recently

[DragonTHC]

I think some shitty Fab is to blame for these batteries popping.

3 years ago, you rarely heard of batteries popping.

lest we forget the markets flooded with cheap aftermarket chargers?

Re:They only started doing this recently

[Hal_Porter]

I found an interesting article that supports that theory -

http://www.electronicsweekly.com/blogs/engineering -design-problems/2007/09/whats-wrong-with-lithiumi on-ba-1.html

But Don Sadoway, a professor of Materials Chemistry at MIT who is an expert in advanced battery technologies, worries about off-shoring of a chemistry he asserts "needs to be treated with respect."

"I have 100% confidence in the Japanese battery manufacturers," he says. "And my guess is that they never had the problems theyre seeing now when the same batteries were manufactured from start to finish in Japan."

He notes that one of the challenges with Li-ion batteries in particular is that it is very difficult to verify that the manufacturing and assembly is being performed according to specifications. Thats because once its assembled into a battery pack, the device cannot be inspected from the outside nor can it be easily tested.

Sadoway points to the separator material between the electrodes as an example. Acting like a kind of fuse, it is designed to soften and collapse at a specific temperature, causing the battery to essentially go into an open circuit condition and die.

In fact, he wonders why that didnt happen in the case of the Dell laptop that burst into flames last year.

"You could think you are specifying a porous polypropylene material for the separator, but once the thing is packaged up you would have no way of knowing what you actually got. Even under the best of circumstances, you can get screwed by your own job shop. What if the workers took a short cut and substituted the original material with cardboard?"

Even better there's a link to that article in the writeup! Pretty handy.

Re:They only started doing this recently

[rsmith-mac]

No, this isn't recent, it's only more sensationalized and is affecting more people overall because of the increased deployment of devices using the technology. Heck, the PowerBook 5300 when first released in the early-to-mid 90's was blowing up due to its LiIon battery - somewhat amusingly that was Sony made too.

Batteries will continue to periodically blow up as long as we use them, it's the inherent result of creating devices with so much energy density.

Fortunately

[evanbd]

Fortunately, we have supercapacitors. While they're not there yet for energy density (still about 10x too little) they're rapidly improving. 10x isn't much at the rate these things have been improving, and there are plenty of labs with pieces that are much better than currently available commercial offerings, but that still need development work. If I had to guess, I'd say it's 5 years until the first supercaps appear in serious commercial use, and less than 10 until LiIon has gone the way of NiMH.

Of course, if you believe the rumors then it might be even faster than that -- we might be seeing serious applications in a year or so.

I, for one, will be glad to give LiIon a proper burial. But until then, we work with what's available.

Re:Fortunately

[Stevecrox]

You realise capacitors explode if you put to much energy into them right? So your argueing instead of using a technology that builds up and catches fire we instead compress the energy into a smaller density in a design which can and does explode. Sure there might be easier ways to contain an explosion. But its not better it just presents different problems.

Re:Fortunately

[Alioth]

Depending on the characteristics of the supercapacitor, they can be even more dangerous. Capacitors generally can discharge at incredibly high rates. With the high energy density of an ultracapacitor, the effects will be spectacular.

If you want to see what just a few nanofarads of charge can do, take a look at a Tesla coil, or perhaps this - the Destruct-o-Tron: http://www.electricstuff.co.uk/destructotron.html

Re:What's wrong? They store to much energy!

[Anonymous Coward]

NNUTS.

Back when alkalines were hot news, a 9V Dur* I was carrying in my pants suddenly became hot. As I was worried it would catch fire or even explode, I stopped the bus to throw it out.

(API)

The reason behind the problem is simple

[harlemjoe]

The Coward who posted this writes:

The reasons behind the recent spate of problems with a technology invented by Sony more than a decade ago are complex and varied,

No, the reasons are not ambiguous, they are clearly outlined. There is nothing wrong with the technology, the entire problem is the lack of quality control in battery factories in China. Sony is not the only one to get screwed by poor QC in Chinese factories, so has Mattell who are scrambling to recall ~20 million toys painted with lead paint, and J&J, who are scrambling to recall 10 million fake diabetes kits

In the article itself, fingers are clearly pointed

But Don Sadoway, a professor of Materials Chemistry at MIT who is an expert in advanced battery technologies, worries about off-shoring of a chemistry he asserts "needs to be treated with respect."

"I have 100% confidence in the Japanese battery manufacturers," he says. "And my guess is that they never had the problems they're seeing now when the same batteries were manufactured from start to finish in Japan."

I don't think anybody realizes just how shoddy quality control is in China. Just as there is absolutely no respect for intellectual property, the Chinese, being new to capitalism, don't understand the value of quality control. They've never had to suffer the consequences of legal action.

The culture just does not exist. Some argue that this is a good sign, a necessary phase in capitalism that China is passing through that the USA passed through once before.

I'm not trying to be a troll. China I'm sure will improve and their industry is surely chastened by the huge hue and cry around the world. But until things get better, watch out, and for more than just exploding batteries:

• Here is a famous YouTube video of a Chery subcompact spectacularly failing a crash test in 2005.
  
• And another of the 2007 sedan Brilliance BS6 doing the same.
  
• A China Airlines jet blows up, and company officials paint the logo off of the wreckage.
  

Just setting the record straight ...

Re:The reason behind the problem is simple

[bughunter]

I'm in charge of battery production at a small aerospace company. We buy COTS cells, screen them functionally, and select cells with matched performance characteristics to build 28-volt avionics and ordnance batteries.

Originally, our NiCd and LiIon cells were made in the US, and our screening yields were in the range of 75 to 95%, depending on the chemistry, manufacturer, and screening criteria.

Over the past three years, US manufacturers for the NiCd cells we buy have all outsourced their manufacturing. They are now all made in China, with the exception of one Sanyo cell we buy which is now made in Japan. Yields for the cells made in China are now in the range of 33 to 50%. Mind you, the US distributors are selling these under the same part numbers and performance specs as ever.

The Sanyo cell has actually improved, consistently achieving 95% to 99% yield, and the uniformity of actual capacity (in mA-hr) is extremely high, with sigma of less than 1% of the average actual capacity.

Our perception is that it's a difference in cultural ethic. In general, we are often reluctant to buy materials of any kind from China, because very frequently, the parts that we receive do not match our Purchase Order specifications, or in some cases, have no resemblance whatsoever to the material we ordered. It's like they receive the order, throw something in a carton or crate, label it to match our PO, and ship it (with an invoice). There is no guarantee from supplier to supplier, or even from order to order, that the manufacturer takes any steps to ensure product quality. It's a crap shoot. But we never have problems like this with Japanese or European suppliers.

And on our end, its usually far cheaper to just order the material again, from another supplier, rather than to return the material and try to get the Chinese supplier to fulfill the terms of the order.

For these reasons, our customers (large aerospace prime contractors) generally frown on us using Chinese-made parts.

Re:What a moronic post

[Hal_Porter]

You realise that means that personal injury lawyers save lives? Lawsuit settlements increase the estimated dollar value of human life, so it's easier to justify spending money of engineering work that marginally increases safety. It's probably disproportionate too - one well publicised multi million dollar settlement could make companies engineer things more cautiously even if they risk they are reducing is in an unrelated area.

It's a bit like evolution really, it's a process that improves things without having any idea what it's doing.

Re:Lithium Ions

[AgentPaper]

Close. They thought bipolar disorder was caused by an error of metabolism resulting in urea accumulation in the body, and that you could determine whether someone was bipolar or not by injecting "manic urea" into a rat and seeing whether the rat acted manic. Of course, the rats died, but they were particularly calm about it, and the reason was the lithium compounds in which the urea had been dissolved.

Re:What's wrong? They store to much energy!

[Eivind]

It's inherently dangerous because very high energy-densities nessecarily mean that there's a lot of energy there to be released. Also, everything for that reaction to occur, must be contained inside the battery. (well, if you exclude air-breathing batteries)

It can be made more or less safe, but normally at a cost of reduced energy/pound. This ain't just so for batteries, but for literally *anything* storing large amounts of energy.

Natural gas has certain failure-modes that are ahem, unpleasant. The failure-modes become more likely as you increase the pressure and/or decrease the mass of the container used to hold the gas.

A flywheel used to store a large amount of energy would be unpleasant if it where to ever disintegrate, get out of balance, or somehow drop out of the bearings. All of which become more likely the higher the energy stored and the less material used for securing against these possibilities.

And yeah, batteries, especially those with high energy-densities, have unpleasant failure-modes. If you where willing to accept a twice-as-heavy battery with the same energy-content, these could be made less likely. Hell, even if you where willing to pay more for an equal-capacity battery, the failures could be made less likely. Still, they're always gonna be there.

thats fluoride

[Anonymous Coward]

fluoride compounds have been used to treat mania, and hyperthyroidism for almost 100years. of course these days its in the form of mass medication through the water supply.

http://www.slweb.org/galletti.html

http://www.bruha.com/pfpc/html/thyroid_history.htm l

Factor of Safety

[TimeTraveler1884]

You may be interested to know, the factor of safety is actually very low in aerospace. Meaning, engineers design systems with smaller margins for exceeding design requirements. The reason is weight; every pound you add by over engineering a part's yield strength, is a pound you have to get in the air or fly to space. The industry compensates for this low factor of safety with very strict maintenance cycles and regulations.

If automobiles were engineered like this, we could probably use half the amount of fuel we currently do. The downside is you would have to get monthly or even weekly inspections and preventative maintenance.

Of course, my source could be wrong.

Re:What's wrong? They store to much energy!

[Steve001]

joto wrote:

Anything that contains lots of energy in a small and compact volume, is dangerous. Explosives, and modern batteries, are really not that different. Both contain a huge amount of energy, in a comparatively small area. As battery technology improves, batteries will become even more dangerous.

With old heavy duty, or alkaline batteries, the worst that could happen was usually a leak. While annoying, it usually didn't pose any dangers. Modern batteries catch fire and explode. Eventually, we'll probably have a nuclear powerplant inside our mp3-players, at which time, they will hopefully include some additional safeguards, such as a fuse. But all modern batteries (lithium, lithium-ion, lithium-polymer) will explode or catch fire, if there's a serious enough malfunction.

I think the largest issue with lithium batteries isn't that lithium has the potential to explode, that is its natural tendency. Much of the effort in the design of lithium batteries is to prevent them from exploding.

A larger problem with batteries is that, per a recent issue of Popular Science, lithium is basically the end of the line as far as standard battery technology (power via a difference in materials) goes, unless new elements are discovered that provide better energy density than lithium.

To me, much of the problem with battery life is due to the use of non-replaceable rechargeable batteries. It seems like battery life didn't become much of an issue until a large number of device began using these type of batteries. Battery life isn't as big a problem when you can quickly swap out a fresh set of batteries.

Re:What a moronic post

[hcmtnbiker]

The girl's attorney said that thicker glass, which isn't mandated by government regulations, would have prevented the UNBELTED occupants from being ejected from the truck when it crashed.

Call me heartless, but if the girls didn't care about their safety, why should Ford have?

Back to the article... There still is not a better batter, for size and weight then a li-on. So I'm willing to risk it in applications where I trust the people making the hardware to understand li-on's downfall, it's very bad heat tolerance. The Dell case was one of these, had the laptops been designed with sufficient cooling, many of the incidents would have stopped, even with the defective batteries. TFA claims that the new round of Nokia batteries may, by themselves, short-circuit and overheat, that's not a problem with the battery chemistry, but a problem with the manufacturer.