pra, I've been doing a little research, I've found out that the ion propulsion engines in development in the real world need both a propellant, which is xenon, a noble gas heavier than nitrogen and electricity. Here's a video of how a real ion propulsion engine works, it might help your development and knowledge.
Speaking about the xenon, this is the first used method to get xenon gas from air, it happened first in 1898, scientists William Ramsey and Morris Travers got xenon as residu of the distilled liquid air.
So, there might be 2 steps to take to make xenon, step one: liquify air, step 2: distill the liquid air.
Do a little research on that.
This means you will have to add a distillator/air separator, air liquefier and more stuff. More info about air separation: https://en.wikipedia.org/wiki/Air_separation
So, don't forget to add these features for an update, to make it more realistic in ion propulsion.
Another propellant for ion propulsion is dilithium (Li2), which could cause your mod to get a little feature from the series of star trek. In these series, it's found in crystal compound, which seems to be fictive. However, if dilithium crystals are explored, found and if there's any hard evidence to prove it exists, it no longer can be considered as fictive. Here's more info about this compound: https://en.wikipedia.org/wiki/Dilithium
For the production/synthesis of dilithium, ask a chemist