Why won't my iPod charge?

Hi everyone! This is my first time posting so please be gentle.

When I press the top button of my Ipod touch 6, the device turns on normally (with the Apple logo) , the unlock screen appears, I type in my password and get access to the control screen.

At that point, my Ipod functions normally, I can go on the internet, check my emails or listen to music. However, after 5 minutes of use my Ipod turns off as if the battery had died (the black screen with a revolving circle appears). I have tried plugging it in with various cables/power adapters but my Ipod won’t charge and the lightning bolt icon doesn’t appear. The battery remains under 20% however long I keep it plugged in.

Do you have any idea where the problem might come from? Is my device salvageable?

Thank you very much for your answers!