Notable appearances: Batman: The Animated Series, Batman Begins
Batman doesn't usually carry explosives on him, but his miniature Bat-Bombs are an exception. Used most often to blow locks off of doors or to knock down walls, these little bits of mayhem are very rarely used for offensive reasons. Most famously, Batman used these bombs to escape from the reinforced confines of Arkham Asylum during Batman Begins.
Being no larger than a golf ball, these bombs are easy to carry around in case they are ever needed. A version of this same idea also appeared briefly in Batman & Robin when the dynamic duo used some gaudy looking Bat-Bombs to blow up Mr. Freeze’s makeshift spaceship. But the less said about that, the better.