Study On In Situ Solidified Polyurethane Solid Eletrolyte

In recent years,dye-sensitized solar cells?DSSC?have developed rapidly due to their low-cost,easy-fabricantion and excellent performance.Meanwhile DSSC is composed of a photoanode,sensitizing dye,an electrolyte and a counter electrode.The electrolyte plays a role of electrons transport and dye regeneration,which has an effect on the photoelectric performance of DSSC.In order to solve the problems of the weak electrical conductivity and the poor penetration in porous TiO₂electrode of the solid-state electrolyte,a kind of in situ solidified polyurethane?PU?solid electrolyte system was studied in this paper.In addition,the conductivity of the solid electrolyte should be further increased by adjusting the composition and the structure of the soft segments of PU electrolyte,and adding pyridine,nano-carbon materials,ionic liquids,and subsequently the power conversion efficiency of DSSC.The effects of the molecular weight of PEG,the ratio of hydroxyl-terminated silicone oil?DBP-C22?,pyridine concentration,different nano-carbon materials and different dosages of ionic liquid on conductivity of PU solid electrolyte were studied in this paper.The results showed that the conducticity of PU solid electrolyte reached 4.22mS?cm^-1based on a 1:1 molar ratio of PEG10000 to DBP-C22,0.1mol?L^-1pyridine,graphene and 2.42%ionic liquid.The photovoltaic conversion efficiency of in situ assembled DSSC based on the optimized electrolyte reached 3.69%under the illumination of 100 mW?cm^-2.The results of SEM and DMA showed that the solid electrolyte had a three-dimensional network structure and high elastic modulus.The DSC curves showed that the electrolyte had a good thermal stability in the range of 20?¹40?.The AC impedance spectra and SEM figures of the cross-section of the DSSC showed that there was a good contact of the in situ solidified PU electrolyte with the TiO₂ electrode.The composition of the electrolyte had a great influence on the interface resistance of the TiO₂ electrode/electrolyte of the DSSC and the Nernst diffusion resistance of the electrolyte.