The ones whose rank we don't know
Up to the last chapter, we know who are the espadas 10th, 9th, 8th, 6th, 5th and 4th leaving the 7th, 3rd, 2nd and 1st place open.
Now, recently on the anime saw there is another really hot chixor in the espada lines. Given the current knowledge on Noitora's past, who can't stand that a woman be stronger than him, can we assume that she's the 7th Espada? This theory is given only by excluding her backstory and just give for certain that she was transformed and acquired her Espada position ipso facto
Also, she was looking on Ichigo's vs Grimmjaw fight from pretty afar, seeing ichigo how he managed to be on par with and in the end outstand him, maybe she realized she was no match to someone who beat and upper ranked Espada