Eli5: What exactly is happening, or changing, in a lithium battery when it “wears out” to cause it to have a diminished capacity?

Question

When you read about it, you’ll learn that the average lithium battery can take about 300-500 charge cycles before its considered worn out. What exactly changes inside the battery for it to reach a worn out status?

In: 217

Answer 1

Can someone please expand: why do they say lithium batteries won’t leak whereas other batteries will leak