The Research Of High-performance Counter Electrode And Gel-electrolyte In Dye-sensitized Solar Cells

Energy is the most important issue of the21st century. With the consumption of conventional fossil fuels, exploring new alternative energy, such as solar energy, wind energy, nuclear energy, hydrogen energy, tidal energy, bioenergy etc., is the only way to meet the increasing power demand and solve the energy crisis. Solar energy is one of the inexhaustible and renewable energy resources, while which also is one of the most abundant and safest clean energy resources. Exploring and exploiting solar energy is the most important way to realize the sustainable development of human society.Since the first report of dye-sensitized solar cell (DSSC) by O’Regan, B. and Gratzel M., it has received the world wide research interests for its low cost, relatively high energy conversation efficiency, facile manufacture process. The researches of DSSC includes of anode film, dye molecule, electrolyte, counter electrode etc. While enhancing energy conversation efficiency, reducing cost, enhancing the stability of cells are the three most important issues. Our researches in this paper are focous on the three issues. To enhance efficiency, we manufactured high catalytic activity Pt counter electrodes; For the purpose of reducing DSSC cost, we prepared conductive polymer and conductive polymer supported Pt nanoparticles counter electrode to replace the conventional Pt counter electrode; In orde to enhance the stability of DSSCs, we prepared superabsorbent polymer based gel-elelctrolytes, which show high conductivity and high stability.The specific researches can be summarized as follows:1) With the aid of PC film template, a Pt nanotube (PNT) based counter electrode was prepared. Compared with the conventional Pt electrode, the PNT electrode shows a much enhanced electrochemical catalytic activity; A DSSC based on the PNT counter electrode was fabricated, and a relatively high efficiency of9.05%was achieved.2) By using a modified constant potential electrodeposition in high concentration of H2PtCl6, a "Pt flower" structure counter electrode was prepared. The surface of "Pt flower" is composed of numerous of petal-like platinum nanosheets with a thickness of25-30nm, such structure greatly enhances the active surface area and improves the catalytic activity for I3-reaction, thus it leeds to a improved light-to-current conversion efficiency. 3) A PANI nanofiber coated film was directly grown on conductive glass substrate by electrodeposition method. A DSSC based on the PANI nanofiber structure was fabricated, and an light-to-current conversion efficiency of6.85%was achieved. By a second electrodeposition, Pt nanoparticles were further deposited onto the surface on PANI nanofiber, thus a hybride PANI/Pt film on glass substrate was formed. The DSSC based on the PANI/Pt nanofiber structure was also fabricated, and an enhanced light-to-current conversion efficiency of7.69%was achieved.4) Two amphiphilic and conductive superabsorbents of polyacrylic acid/gelatin (PAA/Gel), polyacrylic acid-g-cetyltrimethyl ammonium bromide (PAA-g-CTAB/PANI) were prepared, based on which, gel-electrolytes with high conductivity over14mS·cm-1were prepared. A DSSC based on PAA/Gel/PANI superabsorbent reached the highest efficiency of6.94%.