system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: why do laptop batteries have a shorter life after a while, and how can you best use a laptop battery so it has a longer life?

Edit: thank you so much for all the info, this helped me understand a lot.
gpt
It has to do with the chemical structure of a Lithium battery.  The way a lithium battery works is that during operation Lithium ions are removed from a lithium bearing compound from one contact, transferred across an electrolyte, and deposited on the other contact.  When recharging, the process is reversed.

The degradation comes from the fact that each time the cycle is performed, impurities are introduced into the structure of contacts, reducing their effectiveness.