Battery with inbuilt 'fire extinguisher' developed | Hacker News Reader

Battery with inbuilt 'fire extinguisher' developed

bbc.com

The reason for recent battery issues have been primarily because manufacturers are pushing for tighter tolerances to make more energy dense batteries and smaller safety spaces in battery compartments. At the point they build in a fire extinguisher, why not go back to roomier batteries and compartments? Does this built in fire extinguisher impact the battery size and tolerances or does it replace existing materials? It was disappointing to not see that covered in the article.

If my skimming of the journal article (http://advances.sciencemag.org/content/3/1/e1601978.full ) is accurate, they really only built a prototype.

So it's more of a demonstration that the flame retardant can be placed in a battery separated from the electrolyte by a heat activated membrane than it is a fully engineered end user battery.

I was wondering whether it would make sense to put some very smelly gas, just like you do with bottled gas.

Battery leaks would be then easily detectable by human nose.

https://en.wikipedia.org/wiki/Ethanethiol

If only they could do this for 18650 batteries which goes into vaping device that would be great, so many careless users blow up their face while vaping because they have no knowledge of battery safety or ohm law when building their coils.

I don't know anything about the vaping space, but have seen some of those horror headlines of them exploding in people's pockets.

Why do people have to build their own coils? Do they have to do some DIY, or can you just buy a vaper off the shelf?

I don't need to know Ohm's Law to use my cellphone, etc. Why for this product class?

You can purchase mass produced stuff but the quality of vape you get is much better with DIY setups, though it puts the onus of safe design parameters on the builder. With electronically regulated devices this risk goes down a great deal, older gen (though still in wide use) devices called mechanical mods would basically short circuit a lithium battery to a coil of wire - if the resistance is too low you pull way too much power for the battery and catastrophic heating occurs.

People don't have to build their own coils - there's plenty of devices on the market that take factory-produced cartridges with a coil & wick all set up for you, you just swap out the cartridge when it gets old. Most casual "vapers" just use those, for convenience as much as for safety.

But building coils is a hobby in its own right - there's lots of different variables you can tinker with (coil diameter, number of turns, wire gauge, wire material, wick material, wicking style, multiple coils in parallel, ...) and get slightly different results. It's fun to experiment, and there's a sense of achievement when you get a complicated build working just right. It appeals in the same way that overclocking your computer does, for example, or tuning your car/bike engine.

Also, all those cartridges will eventually be discontinued as the manufacturer moves on to new devices - but you can keep using a rebuildable device as long as you can get suitable resistance wire (Kanthal A1, Nichrome, or a certain grade of stainless steel) and wick (organic cotton, cellulose fibre, or silica yarn). And those raw materials cost basically nothing per coil, compared to a few dollars for each of those cartridges.

I think building in a simple fuse would be cheaper and easier.

A fuse won't protect against over-charging or over-discharging. (PTC resettable fuses are great to break continuous overcurren, though!)

Over-discharging?

Drawing too much in a period from the cell.

Lithium-ion batteries can be damaged if discharged below around 3v. The protection circuit on a protected battery will normally disconnect the battery at around 3.3v to prevent damage.

I have had to dispose bulged batteries, which are classified as household hazardous material. Craigslist forbids doing business involving such materials so I could not hire someone to do a dump run. Had to go all the way to a dump transfer station myself.

Lithium ion or lithium polymer batteries can become dangerous through overcharging and overdischarging, manufacturing defects, damage, etc.

It is a good idea to take a look at it once in a while and if it is bulged, dont use it.

I'd be inclined to skip this sort of thing on handheld-scale batteries.

It only makes sense when a large battery serves as a power store for something like a vehicle, where a fire extinguisher stands between a cabin full of concussions and a cabin full of charred corpses.

Cell phones are sold to us as disposable trash, that corporations and governments use to eavesdrop on our lives. We're trained to sneer at a cell phone more than a year old.

From Wikipedia:

  However, an increasing number of studies 
  have linked exposure to TPP with reproductive 
  and developmental toxicity, neurotoxicity, 
  metabolic disruption, endocrine effects, and 
  genotoxicity. TPP has also been found to 
  induce significant estrogenic activity

https://en.wikipedia.org/wiki/Triphenyl_phosphate

There aren't a lot of teeth to regulations for responsible battery disposal. Even in countries with healthy recycling programs. If I threw all my old cell phone batteries into landfill today, I could safely gamble with any punishment risked.

Now add unspent fire suppressant to the list of things that go in the garbage with last year's cell phone?

Halogenated fire retardants are some of the worst persistent organic pollutants, so like you I looked up triphenyl phosphate to see if it's likely to become a problem in its own right. It looks pretty safe to me when you consider all factors.

In active batteries triphenyl phosphate remains separated from humans. In proper recycling processes it remains separated from humans. In improperly landfilled batteries it can escape containment, but it has negligible vapor pressure at ambient temperatures so it won't spread by air. It rapidly biodegrades in the presence of water so it won't lead to human exposure through waterways or groundwater plumes if a landfill leaks.

I could understand this for larger batteries, I'd hate to see the damage a Powerwall or something similar could do when someone lets the work experience kid do QA for a few hours.

See for yourself: https://electrek.co/2016/12/19/tesla-fire-powerpack-test-saf...

"If a lithium-ion battery cell charges too quickly or a tiny manufacturing error slips through the net it can result in a short circuit - which can lead to fire."

How about solving the obvious problems?

So, guarantee 100% reliability forever? Sounds obvious, but is it easy, or even possible?

Better to stop the reaction in its tracks and allow the engineers to see where things go wrong than to assume the battery will always work. I'm sure the engineers behind the Boeing 787 and the Galaxy Note 7 also believed with confidence that their batteries would be fine.

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