I would guess that microfractures in the glass would impede the movement of charge carriers, even if it didn't shatter outright.
It wouldn't be good for the battery to hit it with a hammer, I think, but that really applies to any high-energy-density battery. Not all glasses are created equal, either. It all depends on the composition and the cooling regime. Some glasses can shrug off small-caliber bullets, and others will crumble under your fingertips.
