1.Institute of Solid State Chemistry and Mechanochemistry, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia, 630128 ;2.Novosibirsk State University, Novosibirsk, Russia, 630090 ;
Abstract:
Proton conductivity, morphology, phase composition and mechanical properties of (1-x)CsH2PO4-xp(VDF/HFP) (x?=?0.05–0.25, weight ratio) polymer electrolytes were investigated for the first time. The chemical interaction of the organic matrix and acid salt was not observed and crystal structure of CsH2PO4 was preserved. A method for the synthesis of thin membranes with uniform distribution of the components was proposed. Thin flexible membranes with uniform distribution of sub-micrometer CsH2PO4 particles in the polymer membranes and improved hydrolytic stability were obtained firstly by using a bead mill. The mechanical strength of the hybrid polymer compounds was determined using the Vickers microhardness measurements. Proton conductivity in the (1-x)CsH2PO4-xp(VDF/HFP) electrolytes decreases monotonically with x increase due to the «conductor–insulator» percolation. Nevertheless, the values of proton conductivity remain sufficiently high, and along with small thickness, flexibility, improved mechanical and hydrophobic properties, it makes polymer electrolytes based on CsH2PO4 promising for membranes of medium-temperature fuel cells.