Unless he's learnt his Zanpakuto's name, no.
Yachiru, like Kenpachi, doesn't have a Bankai since she doesn't know the name of her Zanpakuto.
Of course he does!! All soul reapers have a zanpaktoe and that would explain the bonkai.This is false. All soulreapers have zanpakuto, this is true. Only after much training can a soulreaper gain his/her bankai. Kenpachi's shikai is constant, much like Ichigo's, yet because he has yet to even learn his swords name, he cannot obtain Bankai. It makes him an oddity as a captain, as Bankai is a requirement, usually. His removing of his eye patch which acts as a seal for his own power, is comparable to Bankai in some incidents.
All the captains of the thirteen protection squads except Kenpachi Zaraki. And then Ichigo Kurosaki, Renji Abari, and Ikkaku Madarame.
kenpachi doesnt have a bankai or shikai form but if he did he would be wayy to powerful so he probably never will get one, and the eyepatch is just a seal that eats some of his spirit pressure so i doesnt get out of control. also if you where to watch the the anime or even read the manga kanpachi even says his eyepatch eats some of the spiritual pressure.
This would be episode 52-53 I believe and it is Kenpachi vs Tousen and Kamamura. These episodes also contain Ichigo training for Bankai :)
Ichigo zurosaki!!
Up+X activates the Bankai it depends if you SR bar is at 0%.
Its highly unlikely, he doesn't know the name of his zampacto, its stated that it probably already in it shikia form, like ichigo's is, all the time although it might be plausible through rigorous training
get the smashball
You need level 4 Soukatsui for Bankai, my sword is the best, its called bailing, epic bankai.
Ichigo first uses his Bankai in episode 29 of Bleach, titled "The 2nd Division Sorties! Ichigo is Surrounded."
Kenpachi doesn't have a name for his zanpakuto. Therefore meaning he does not have a shikai. Cheers