I figured it just meant running a mild electrical (or other energy) current through them in order to alter their structure.I don't think the writers have any idea what 'polarizing the hull plating' means.
Some substances do rearrange their atoms when energized like that. If your computer screen is thin and flat, then it's probably an example; a "liquid-crystal" display has components that switch back and forth between two different kinds of atomic structure (not exactly liquid or crystal in either case, but that's close enough to get the basic idea), depending on whether or not an electrical current is running through them. In one mode, they're transparent, and in the other mode, they're opaque, so this is used to control how much light is allowed to pass through them. (The background light is always on, even for "black"; the opaque liquid-crystal elements are just blocking that light from getting out to your eyes.)
There might be some other technologies out there that use substances that change structure and traits based on whether or not they're energized, but if so, I can't name them, because they're not as well established as LCD yet. But experiments are underway for other applications, such as a fabric that hangs loose like any other cloth when not energized and then becomes rigid and hard like a thick resin shell when you pass a current through the fabric, or a filter whose holes can be loosened or constricted. (The former has been researched for the military, and was shown in "Batman Begins" as a fully working prototype sheet, which Batman had reshaped a bit made to make his cape, so the cape would harden in the shape a pair of bat-wings he could essentially hangglide on.)
So, given the latest concepts and what might be on the horizon in this materials technology, I simply took hull-plate polarization as an example of a bi-modal material that just becomes more impervious to weapons when it's zapped with a current.