first of all:
I know that a completely discharged battery is damaged permanently. I know it experiences irreversible chemical changes. I know it might blow up if you try to charge it. But that's not at all relevant to my question:
Is it safe to discharge Li-Ion to 0V and short it permanently afterwards?
Point of this question is: I do recycle lot of old batteries (Smartphones, Laptops, …) and of course I also have to dispose some of them from time to time.
But before I dispose them, I have to store them… And I personally want to store them in the most safe state possible.
Storing them "discharged" to ~3V with the device they were used in still preserves lots of energy in the battery. If I store it with ~3V and, let's say, accidentally drop a huge nail on it, it might still go bang.
Discharging it to 0V and shorting it out, I feel a lot safe – at least I think so. This ensures there is no electrical energy in it left and thus no short circuit current might get it to explode.
However, I know pretty much nothing about the chemical changes in the cell and what actually might happen if the battery discharged to 0V (and shorted) might get damaged by a nail or if it even might blow up by its own.
So, is it safe to discharge a Li-Ion battery to 0V and short it? Is it even better than disposing it with 3V charge left (if you have the know-how to discharge it properly of course)?
Thx!
Best Answer
At 3V a Li-ion battery has almost no capacity left.
In this graph two 800mAh batteries were discharged at various rates. At 0.1A there was virtually no capacity left at 3.0V. Even at 1A they were 99% discharged.