Preparation And Conductive Performance Of Phosphorus-containing Substituted Polyoxo-Metalate Electrolytes

Heteropoly acids?HPAs?or polyoxometalates?POMs?are a fascinating kind of inorganic metal-oxygen cluster compounds.They play very important roles in catalysis,biology,electrochemistry and materials science as a consequence of their variety of physicochemical properties.The design and synthesis of HP As and their derivatives have widely attracted researchers' attention.Five substituted heteropoly acids,H₄[In?H₂O?PW11O39]·11H₂O?PW11In?,H5PW10V2O40·14H₂0?PW10V2?,H8P2W16V2O62·20H₂0?P2W16V2?,H6P2W16Mo2O40·29H₂0?P2W16Mo2?and H₄[In?H₂0?PW9Mo2039]· 11H₂O?PW9Mo2In?were firstly synthesized.They were characterized by a series of methods such as IR,UV,XRD,TG-DTA and electrochemical impedance spectroscopy?EIS?.The results of EIS show that all the HP As exhibit proton conductivities more than 10-4 S·cm-1 at room temperature?18??,so they are new kind of solid proton conductor.Their proton conduction proceeds by Vehicle mechanism.Furthermore,18 reversible phase transformation polyoxometalates/ionic liquids,[MIMPS]8P2W16V2062,[MIMPS]6H₂P2W16V2062,[MIMPS]4H₄P2W16V2062,[MIMPS]5PW10V2O40,[MIMPS]3H₂PW10V2O40,[PyPS]8P2W16V2O62,[PyPS]5PW10V2O40,[TEAPS]5PW10V2O40,[TEAPS]7P2W17V062,[TEAPS]8P2W16V2O62,[TEAPS]9P2W15V3O62,[TBTP]5PW10V2O40,[TBTP]8P2W16V2O62,[TOAMe]4[In?H₂0?PW11O39],[TOAMe]7[In?H₂O?P2W17O61],[TOAMe]4PWI1VO40,[TBDA]8P2W16V2062 and[TBTA]8P2W16V2O62 were synthesized from 1-?3-sulfonic group?propyl-3-methyl imidazolium?MIMPS?,1-?3-sulfonic group?propyl-pyridine?PyP S?,1-?3-sulfonic group?propyl-triethylammonium?TEAPS?,tributyltetradecylphosphonium chloride?TBTPCI?,quaternary ammoniums??C4H9?3N?C10H₂1?Br?TBDABr???C4H9?3N?C14H₂9?Br?TBTABr???C8H17?3NCH3Cl?TOAMeCl??and polybasic heteropoly acids?PW11In,PW10V2,P2W16V2,P2W16Mo2 and other phosphorus-containing heteropoly acids:H7[In?H₂O?P2W17O61]?P2W17In?,H7P2W17VO62?P2W17V?,H9P2W15V3062?P2W15V3?,H₄PW11VO40?PW11V??.Their structure,thermostability and electrochemical properties were investigated.The products can undergo a reversible phase transformation from quasi-solid state to liquid state below 100?;and above the phase transition temperature the conductivities of the products increased apparently.Dawson-type POM/ILs usually owe higher conductivity than Keggin-type one.When the proton substituted the ammonium,both the conductivity and the thermo-stability of the compound can be increased a lot.With a decrease in the alkyl chain length,a significant improvement in the conductivity of the ammonium-based POM-IL gels can be achieved,but the ammonium-based POM/ILs still owes lower conductivity than phosphonium-based POM/ILs.Ionic conductivity above 10-4S·cm-1 above was observed at high temperature for these tungstovanadosilicate-based ionic liquids.