Preparation And Properties Of PEO/PVDF/LICLO4 Based Gel Polymer Electrolyte Membranes For Electrochromic Glass

The proportion of building energy consumption in social total energy consumption is higher and higher,and energy saving and environmental electrochromic glass becomes the first choice for reducing building energy consumption.The studies about electrolyte material of electrochromic glass were a few,and gel polymer electrolyte?GPE?has become a hot area of research due to light quality,thick fluidity,reduced risk of leakage and ease of fabrication,PEO/PVDF/LiClO₄/TiO₂/PC GPE was prepared by solution casting method and made up of polyethylene oxide?PEO?,polyvinylidene fluoride?PVDF?,lithium perchlorate?LiClO₄?,propylene carbonate?PC?.The effect of the proportion of PEO/PVDF blend,the content of LiClO₄,the doping amount of inorganic nano-TiO₂ particles and plasticizer PC on the structure and performance of GPE were studied.The researches of PEO blended by PVDF showed that the decomposition temperature of PEO/PVDF was about 390 ?,which proved PEO/PVDF had excellent thermal performance.There was no phase separation phenomenon in PEO/PVDF blend,and the blend of PVDF into PEO leaded to a destruction of structure and a crystallinity decline of PEO.The frature strength of PEO/PVDF firstly increased and then decreased with the increasing of the content of PVDF.The maximum strength of PEO/PVDF was 6.8 MPa when the weigh ratio of PEO and PVDF was 85:15.The ionic conductivity of PEO/PVDF/LiClO₄ film increased with the rise of LiClO₄,but the forming became worse.The electrolyte film has the best performance when the weigh ratio of PEO/PVDF and LiClO₄ was 10:1.After adding inorganic nano-TiO₂ into PEO/PVDF/LiClO₄ based electrolyte film,the ionic conductivity and mechanical property were improved,the average tranmittance reduced,but it still met the actual demand.Ionic conductivity of PEO/PVDF/LiClO₄/TiO₂ electrolyte film reduced when the mass fraction of nano-TiO₂ exceeded 0.5.The fracture strength of PEO/PVDF/LiClO₄/TiO₂ GPE was about 3.925 MPa,which demonstrated about 1.9-fold increment in the fracture strength as compared to that of and PEO/LiClO₄/TiO₂?0.5?.The ionic conductivity of PEO/PVDF/LiClO₄ based electrolyte film firstly increased and then decreased with increasing the amount of PC.The maximum ionic conductivity of PEO/PVDF/LiClO₄/PC was 4.44 × 10-6 S/cm which was 7.3 times as much as PEO/LiClO₄/PC when the mass fraction of PC was 7.The mechanical property of PEO/PVDF/LiClO₄/PC declined when the content of PC increased.The doping of PC has almost no effect on the light tranmittance of PEO/PVDF/LiClO₄ based electrolyte film,whose average tranmittance kept between 94 and 98%.The variation of ionic conductivity of PEO/PVDF/LiClO₄ doped nano-TiO₂ or PC with temperature followed the Arrhenius equation.Compared to the the activation energy of PEO/PVDF/LiClO₄,the activation energy of PEO/PVDF/LiClO₄/TiO₂?0.5?and PEO/PVDF/LiClO₄/PC?7?decreased by 20 and 23.9%,respectively.Co-dopping with nano-TiO₂ and PC,the maximum ionic conductivity of PEO/PVDF/LiClO₄/TiO₂/PC GPE reached 3.11 × 10-5 S/cm when the amount of LiClO₄,nano-TiO₂ and PC were 0.17 g,0.0125 g and 0.125 mL,respectively,which was far more than PEO/PVDF/LiClO₄/TiO₂ or PEO/PVDF/LiClO₄/PC.