Awesome question, Warrior!

Badge Crates have amazing prizes that you earn on every 24 hours.
Just like the Free Crates, you can stack up to two of them at a time.
The main difference between the Free and Badge Crate is that you can only open the Badge Crate once you've got 10 badges from battles.

You earn a badge based on your battle's score.
Destroying your opponent trenches or small bunker will reward you with 1 badge each.
Destroying the main bunker will reward you with 3 badges.

The Badge Crate has awesome prizes, so really try your best to collect 10 badges per day to be greatly rewarded!

Go on and get them! ;)