Как безопасно хранить неисправную литиево-ионную батарею?

I have a defective lithium-ion battery, one that is bulging quite severely and is about 50 percent thicker in the middle than it is at the edges. While the battery still actually works, I have replaced it since it would no longer fit inside my mobile phone and was about to make the screen come loose.

I cannot safely dispose of it just yet, so my question is, is it safe to just leave it unused on a table until I can get around to disposing of it or would it be safer to keep it cool/frozen?

There is likely no need to panic if it is just a week or two until you can properly dispose of it. You want to store it for as short a time as possible. For the most part, unless you stab it, an unused bloated battery ought to be reasonably safe.

On a practical note, you want to leave it somewhere cool and dry, so a refrigerator is not the best place. The refrigerator trick is used for dying batteries in some cases, but not dead ones.

I would suggest taping over the connectors to prevent accidental shorting and just leave it somewhere safe. Freezing a battery does not sound bad until you realize there will be a sudden change in temperature (potentially bad) and condensation (moisture) when you need to take it out.

It is also worth remembering that this happened over the course of weeks or even months before it became noticeable. There was some pressure on the screen and I had assumed it was an air bubble behind the screen protector. I noticed the bloating entirely by accident.

So, short of baking (inadvertently or otherwise), burning or stabbing your battery, or taking a few months to dispose of it, you probably do not need to massively baby the battery. Just do not charge it (and for once self-discharge is fine). A battery not in use is slightly less likely to spontaneously catch fire.

There are a few suggestions that I have seen online, like putting the battery in salty water (which sounds like a terrible idea, especially since lithium reacts violently with water and is a potential source of bloating anyway) or trying to discharge the battery (the energy flow could mean heat which could lead to a fire). The MSDS backs this up suggesting that the electrolyte reacts with water to form HF (which is nasty), the anode with H2, and many other scary things.

So leave it alone, keep an eye on it, avoid Viking funerals, and you should be fine.