Do Li-ion batteries that have become fatigued from charging cycles exhibit any recovery if left unused for a time? Say I use the last of the charge from such a battery and then put in storage for a year or two. Do any slow processes associated with the last vestige of charge leaking away rehabilitate the battery? Or are the internal electrodes shot and just don’t work any more?
I don’t see any reason to think they would. The charging and discharging has deformed the internal structure inside the battery. Entropy has increased. In order for the battery to become more functional, entropy must decrease. The probability of this happening is very low.
To physically fix the battery you would probably need to melt it down, separate all the constituent elements, and then reforge them back into the structure of a new battery.
Kind of like reforging the Sword that was Broken, only with fewer elves.
Lithium ion batteries are lightweight for their size and have a really good energy density. Unfortunately, they don’t age well. Pretty much no matter what you do, they tend to die an early death. Even if you don’t use them, they age and degrade.
If you put a lithium ion battery in storage for a couple of years, even under the best of conditions it will continue to age and degrade and will be much worse off at the end of those two years than it was when it went into storage.
If you want to kill the battery faster, just raise the temperature a bit. It doesn’t even have to be all that hot. Lithium ion batteries are very sensitive to heat.
There are certain formulations of lithium ion batteries that don’t die quite as fast and can withstand more charging and discharging cycles, but these formulations also tend to have a reduced energy capacity and therefore aren’t commonly used in consumer electronics. You only see these types of lithium ion batteries in things like automobiles.