In which episode of the anime did Aokiji (Kuzan) and Akaino (Sakazuki) fight? Coz' it wasn't revealed in the anime. I want to watch the fight between Kuzan and Akainu again, or maybe I missed that episode.

In which episode of the anime did Kuzan and Akainu fight?
The fight has never been shown: it happened in the 2 years gap and at the moment we just know it was on Punk Hazard and that Akainu won after 10 days of fighting (I hope there will be a flashback at some point showing the fight).

This is a video taken from episode 570 in which Jimbei explains the situation.
The fact that they fought on Punk Hazard is explained in episode 582.