my lightning cable has been damaged

So my lightning cable has been damaged but only the one end which we plug to our phone. So i was curious and i left my phone charging overnight knowing that it won’t charge since there is no sign of charging (no charging symbol) but incredibly, my phone is charged to full now. I thought the cable suddenly healed but i don’t think so since there’s still no charging sign. Should i just buy a new cable because i’m afraid that this will damage my battery or should i just let this be?

[Re-Titled by Moderator]