Once a piece is broken, its not best to try to glue or “fix” the piece.
Lids are special, as they are thrown with the pot from the moment it is wet clay. They dry together, are bisqued together, and are glazed together–they’re quite inseparable.
Consider using the pot without its lid, and purchasing another to take its place in the every-day use in your home. You’ll be delighted you did.
If it’s not for cooking purposes, a powerful glue can hold the piece in place, but is naturally prone to breaking again