As we've written before, hardly any material in the Star Wars universe can stand up to a lightsaber, save a few:
Among these are substances like phrik, cortosis and Mandalorian iron, which have been used to create weapons and armor that can deflect or short-circuit lightsaber beams. There's a precedent for lightsabers made of phrik: Emperor Palpatine's lightsaber was, according to Star Wars: Revenge of the Sith: The Visual Dictionary. In Star Wars video games, cortosis has been shown to block lightsabers, and sometimes shut them down.
Sharp fans will point out that these technologies mainly exist in the expanded universe of Star Wars books, games and other merchandise that's unrelated to the films. Producer J.J. Abrams rejected the expanded universe for "The Force Awakens," much to the dismay of many. But lightsaber-resistant eletrostaffs do appear in the prequels, and it seems as though Abrams has allowed the idea to come back for Episode VII.