Once upon a time a chem-type told me a Li-Ion cell's electrodes went irreversibly into solution if the cell was allowed to drop too low for too long, and the all-knowing internet confirmed it. Plus I had a large number of actual cells gone high-Z to prove it.
Appears t'ain't so any more. I just charged some cells with a 1998 date code, stored at 0v for several years at least, and measure full capacity.
Who'da thunkit?
My OmniBook 600c--the fastest computer I own--will be very pleased.
Cheers, James Arthur