Board Thread:Questions and Answers/@comment-10797017-20130627100621/@comment-11051098-20130808141630

It's true that Kenpachi doesn't kill off opponents who can't fight back. But Nnoitra got back up after Kenpachi refused to kill him, and almost cut him in half with Kendo. And when the fight was over, Nnoitra lied on the ground with a visible massive blood loss.

I think everything points at Nnoitra being dead. Besides, Kubo himself have confirmed that only Harribel and Grimmjow are alive, of the Espada.