Swollen lithium cells...

[Externet]

Hello. A bunch of questions... Please move if deserved to 'Power electronics' or else.
Please answer whatever is known but surely known without guesses ? I want to learn it correctly.

What is the reason for lithium polymer cells swelling ?
age ?
number of cycles of usage ?
spent ?
lack of use ?
overuse ?
heat ?
why a new unused cell can also swell ?
overcharge ?
overdischarge ?
too fast charging ?
too fast discharging ?
improper storage temperature, or at wrong state of charge ?
If pin pierced, vented and sealed like with tape, are they useable ?
any way to prevent the swelling ?
If explode (rupture) with no fire, what ?
can they be used swollen ?
any 'repair' procedure ?
why a spent, old, poor performing lithium cell does not show swelling ?
brands that do or that do not swell ?
chemistries that do or do not swell ?
incomplete charging cycles ?
...add your own...

No, I do not care about the 'battery university' site.

 

[dick_freebird]

I'd bet on an overtemperature event that boiled some
electrolyte.

An "old, spent" cell which never got cooked the same
way would not exhibit the same result.

Some cell types and manufactures are more tolerant
of overcharging. Some might contain getters or catalysts
which would reform charging gasses. But steam is on you.