Papers by Keyword: Polymer Gel Electrolyte

Abstract: A series of copolymers P(VP-HEMA) composed of hydroxyl ethyl methacrylate (HEMA) and 4-vinyl pyridine (VP) were prepared by a solution copolymerization technique. Based on the copolymer P(VP-HEMA) prepared by the content of VP 50%, the amount of AIBN 3% and the optimized liquid electrolyte, a polymer solution electrolyte with concentration of 9.0% was formed. By addition of 1,4-dibromobutane into the solution, the copolymer gel electrolyte with higher conductivity 6.14mS/cm was prepared. Gelation is caused by the quaterisation between the group of pyridine in P(HEMA-VP) and 1,4-dibromobutane. Based on the copolymer gel electrolyte, a dye-sensitized solar cell was fabricated with short-circuit current of 13.62mA/cm²,open circuit voltage of 0.72V, fill factor of 0.5465 and an overall conversion efficiency of 5.24% under irradiation 100mW/cm² (AM1.5).

Abstract: A series of copolymers P(MMA-NVP) composed of methyl methacrylate (MMA) and N-vinyl pyrrolidone (NVP) were prepared by a solution copolymerization technique. The copolymer could absorb and capture amount of liquid electrolyte within its chain networks structure to form quasi-solid-state electrolyte. The influences of synthesis conditions for copolymers, such as the content of NVP, the amount of initiator 2,2’-azobisisobutyronitrile(AIBN), and the amount of crosslinking agent triethylene glycol dimethacrylate(TEGDMA) on the ionic conductivity of quasi-solid electrolyte were investigated. The highest conductivity of the copolymer gel was 2.17mS/cm at 25°C. Based on the copolymer gel electrolyte, a dye-sensitized solar cell was fabricated with short-circuit current of 12.16mA/ cm², open circuit voltage of 619mV, fill factor of 0.4633 and an overall conversion efficiency of 3.05 % under 100 mW/cm2 irradiation (AM1.5).

Abstract: Nanostructured ZnO films for use in dye-sensitized solar cells were fabricated by utilizing a chemical bath deposition process and a newly developed liquid–liquid process. Layered zinc hydroxides were first deposited on fluorine-doped tin oxide (FTO)-coated substrates and then heated at 450 °C in air to obtain ZnO. Cells were constructed by employing a quasi-solid-state polymer gel electrolyte. The performance of the cells with the ZnO films from the different deposition processes was compared and discussed in terms of the microstructure. Light-to-electricity conversion efficiency reached 2% in all the cells under full sunlight. The cells were kept for 500 h at room temperature, revealing that they maintained 90% of their initial performance.

Abstract: Poly(vinylidene fluoride)(PVDF) is photochemically stable even in the presence of TiO2 and Pt nanoparticles, and poly(methacrylate)(PMMA) has good solvent retention. The quasi-solid electrolytes based on PVDF-PMMA blend polymer were prepared in this work by soaking a porous membrane in an organic electrolyte solution containing the I−/I3− redox couple. The as-prepared electrolytes were characterized by means of Fourier Transform Infrared Spectroscopy, Scanning Electron Microscope respectively. Moreover, the conductivity and the voltage-current curves of the electrolytes were measured by electrochemical workstation. The results indicated that the optimum blend proportion of PVDF and PMMA was 6:4. The porous structure prepared with the addition of propanetriol was beneficial to ion diffusion and thus enhanced the conductivity of the electrolytes. The gel polymer electrolyte had a conductivity of 0.14 mS•cm-1 under the ambient atmosphere. Furthermore, electrolytes were assembled to fabricate DSSCs and the performance of the cells was tested. The good properties with the open-circuit voltage of 0.60V and the short-circuit current of 1.1mAcm-2 were achieved upon illumination with visible light.

Abstract: Electrochromic materials have attracted considerable attention during the last two decades as a consequence of their potential application in several different types of optical devices. Examples of these devices include intelligent windows and time labels. In this paper the authors describe results obtained with thin tungsten oxide films produced at room temperature by rf magnetron sputtering under an argon and oxygen atmosphere on transparent conductive oxide coated glass substrates. To protect the surface of the electrochromic film, prevent water absorption and obtain a good memory effect under open circuit voltages, a layer of Ta2O5 was deposited over the WO3 films. In this study, the effect of different electrolyte compositions on the open circuit memory of optical devices has been characterized. The best results were obtained for electrochromic devices with polymer gel p(TMC)3LiClO4 and p(TMC)8LiClO4 electrolytes. These prototype devices present an overall transmittance of ~75% in their bleached state and after coloration 40.5 and 52.5% respectively. These devices also show memory effect and an optical density considered satisfactory for some electrochromic applications.