A new polyfunctional acid material for solid state proton conductivity in dry environment: Nafion doped with difluoromethandiphosphonic acid
Abstract A major application of polyfunctional acid materials is the fabrication of solid electrolytes exhibiting high proton conductivity in the solid state for operation in fuel cells at medium temperature ( 3 H ionic domains. The XPS data provide direct evidence of the interaction between the DFMDP PO 3 H 2 and Nafion SO 3 H groups which allows the proposition of the establishment of H-bonding network between the proton acceptor P = O and P–OH sites and the proton donor SO 3 H group. The conductivity data for the DFMDP membranes, compared to other data obtained for membranes made by other sulfonated polymers doped with H 3 PO 4 , offer intriguing perspectives for the design of solid electrolytes exhibiting enhanced conductivity in dry or low humidity environment.