The reason a #laptop is under a lot of stress at 100% is due to its #lithium-ion battery. It consists of two layers, one made of graphite and the other made of lithium cobalt oxide, with lithium ions passing between them. A fully charged #battery looks like (mostly) all of the lithium ions in the graphite layer, releasing energy to your computer.
https://qz.com/laptop-battery-charging-plugged-in-myth-1851324700