The present application discloses a method for preparing an electrochromic device. The method includes placing an edge protection material on a first and second substrates, placing a first and second interlayers respectively within the edge protection material on the first and second substrates, wherein the edge protection material surrounds edges of the first and second interlayers, and interposing an electrochromic film between the first and second interlayers. The edge protection material prevents chemicals in the first and second interlayers from entering into the electrochromic film.