Patent ID: 8492297

Claim:
An electrochromic device comprising a glass substrate made of a soda lime silica glass composition of following composition: SiO 2 55~75 wt % Na 2 O 1~8 wt % K 2 O 1~9 wt % CaO 7~12 wt % ZrO 2 1~8 wt % SrO 3~9 wt % BaO 0~12 wt % MgO 0~5 wt % Al 2 O 3 0~7 wt % B 2 O 3 0~3 wt %, wherein the total amount of Na 2 O and K 2 O is in the range of 5˜12 wt %, the total amount of CaO, MgO and SrO is in the range of 10˜24 wt %, wherein the glass substrate has a strain-point over 570° C. and wherein the glass substrate has a thermal expansion coefficient of 60-85×10 −7 /° C.