Recent studies of our group on polymer electrolytes for improving the long-term stability of dye-sentitized solar cells (DSSC) are summarized.We designed and synthesized a series of novel network gel polymer electrolytes having soft polyorganosiloxane main chains with grafted polyether as inner plastisizer or at the same time with quaternized ammonium side groups.We also synthesized PEO-based gel polymer electrolytes and PAN-based gel polymer electrolytes containing polyorgano siloxane quaternized iodine salt.These electrolytes were successfully employed in dye-sensitized solar cells.The ionic conductivity

electrochemical stability and mechanical processibility of these electrolytes meet the requirement of practical applications.Through optimization of the electrolyte components the photoelectrical conversion efficiency can be improved further.A novel system of in situ solidifiable polymer electrolytes was developed.The quaterization reaction of liquid latent chemical crosslinked precursors was used to prepare polymer electrolytes.This method can realize the in situ solidification of polymer electrolytes and facilitate the industrialization in a large scale.Chemical crosslinked precursors with low viscosity can easily penetrate into the electrode

which can reduce the contact resistance dramatically between electrolyte and electrode and favor the improvement of photoelectrical properties of solid state DSSC.Several types of dendritic oligo-polymers and co-polymers containing pyridine groups and copolymers containing imidazole groups as latent chemical crosslinked precursors were designed and synthesized

and they reacted with multi-halogen compounds to prepare all solid state polymer electrolytes.Also

the gel polymer electrolytes and quasi solid state polymer electrolytes were prepared in cooperation with liquid electrolytes and ionic liquid electrolytes.The photoelectrical conversion efficiency of dyesensitized solar cells constructed by gel polymer electrolytes and quasi solid state polymer electrolytes basically maintain the level of corresponding solar cells constructed by liquid electrolyte and ionic liquid electrolyte.The optimum values are close to 8% and 4.5%

respectively.The poly(ether methacrylate) grafting ionic liquid groups at the end of the polymer chain was designed and synthesized.DSSC using quasi solid state eletrolyte with such polymer and multicomposed ionic liquid electrolyte can reach the photoelectrical conversion efficiency of 6.10% and possess good thermal stability.