Making Safer Lithium-Ion Batteries

itwbennett writes "Exploding iPhones may be a thing of the past. Researchers at Taiwan's Industrial Technology Research Institute have developed a new polymer, STOBA (that's self-terminated oligomers with hyper-branched architecture to you and me), that is added to the cathode material inside a lithium-ion battery to keep them from overheating. 'Fires or explosions in these batteries are caused by short circuits,' said Wu Hung-chun, a researcher at ITRI, explaining that even minor mishandling such as dropping the handset could result in damage causing a short circuit. 'The technology is ready for lithium-ion batteries used in electronic devices, mobile phones, laptops,' said Wu. And ITRI has started testing STOBA on electric car batteries."

Re:Half the fun is in the danger

[thomasdz]

From the wikipedia article on "Lithium": . Lithium batteries are not to be confused with lithium-ion batteries, which are high energy-density rechargeable batteries.
So I'm thinking it was the old non-Lithium-ion batteries that you could get ribbons of Lithium metal from. TFA is discussion the -ion variant battery.

so this is how it works...

[wizardforce]

Apparently the polymer (as far as I can tell) undergoes a cross-linking reaction that acts to slow the movement of Lithium ions following puncture of the battery thus keeping the reaction relatively under control.

http://www.itri.org.tw/eng/Research/Focus-Area/focus-sub-area-category.asp?RootNodeId=0301&NodeId=03013&FieldCD=03200 [itri.org.tw]

Nothing to do with iPhones

[beelsebob]

Ugh, exploding iPhones again... And yet another misunderstanding about what's going on.

iPhones do not use lithium ion batteries. They use lithium polymer batteries.

Re:Step 1

[Anonymous Coward]

it's not just discharge rate. it's pure energy density.

ni-hm just can't store as much energy compared to lithium ion for the same size. The new hybrid Ni-HM probably has a far lower discharge then lithium-ion but that still doesn't solve the problem of lack of energy capacity. People want things to run long on a single charge (like laptops lasting 2 hours vs laptops lasting 4 hours). Most low drain devices where battery energy discharge would matter generally aren't on the radar for most people since charging within a few weeks span is simple compared to charging every few hours which is annoying and impractical.

Re:Half the fun is in the danger

[h4rr4r]

Yeah, it is lithium not lithium ion. Meth cooks use it to replace the sodium in the Birch reduction process AKA Nazi Method. It is far easier to get the lithium from a battery than it is to get pure sodium.

Already make safer lithium/ion

[Hollovoid]

The additive is usually in the separator that keeps the lithium and cathode apart (which you want to do). When the battery overheats the separator breaks down and disables the battery, this has been used where I work for over 20+ years, and is in no way new tech. Putting the same thing in the cathode is like putting a guard rail on the very edge of a cliff instead of 15-20 ft from a cliff, it may stop small shorts that slowly develop in the battery, but a major short, or hole in the separator will melt down and become quite dangerous before the cathode is even involved. Plus, how hot before this effect happens? Cathode is heat treated at over 650F, I sure hope it doesnt take that much to trigger this new substance.

Re:Half the fun is in the danger

[lysergic.acid]

You can buy pure lithium from chemical supply shops. Most people buy batteries to use as batteries. And you can experiment with potentially dangerous compounds and still be safe about it. The danger isn't the fun part. If danger is what you're after then go play Russian Roulette or go streaking across a busy freeway. Having your electronics ruined by a defective battery is neither fun nor entertaining. And the normal risk of it happening is too low to be exciting even if you are looking for danger.

Also, elemental mercury ingested (or injected intravenously) is normally not that dangerous except in cases of chronic exposure, as only 0.01% is actually absorbed by your gastrointestinal tract. It's inhalation of mercury vapors that is dangerous as even small quantities inhaled can cause acute toxicity. But even without experiencing acute mercury poisoning, its cumulative nature can still cause subtle negative health effects (such as higher chances of having children with birth defects in the case of women).

Re:Step 1

[russotto]

Ni-MH is the superior fucking choice. But the self-discharge rate is too high for the plebes to accept. They've got ones that sacrifice capacity for a lower self-discharge rate (such as Sanyo's Eneloop design), but Li-Ion is firmly entrenched, unfortunately.

Yeah, NiMH is way superior to lithium ion. Well, except the memory effect, self discharge rate (near 0 for lithium ion, high for NiMH), the energy density (higher for ordinary LiIon, much higher for LiPo), charging efficiency (~70% for NiMH, ~95% for LiIon), and power density. Except for all that, NiMH is way better than LiIon.

Re:Battery-related paranoia

[Anonymous Coward]

Watch your double negatives. You're saying that the disc told him NOT to NOT put the battery there, which would be the same as putting it on the armature. You meant to say that it warned him against doing it.

Re:Nothing to do with iPhones

[Anonymous Coward]

You realize that a lithium polymer battery is a lithium-ion polymer battery? If it were a true lithium polymer battery, you'd have to buy a new iPhone every time the battery ran down. Wait, crap, don't tell Steve Jobs!

Re:Everybody Have Fun Tonight...

[Hal_Porter]

He's not a Chink, he's Taiwanese. What you're doing is like calling an American a limey.