Cover Image

Proton-conducting membranes based on CsH2PO4 and copolymer of tetrafluoroethylene with vinylidene fluoride

Irina N. Bagryantseva, Yuri E. Kungurtsev, Valentina G. Ponomareva


In this work, proton conductivity, morphology and mechanical properties of (1–x)CsH2PO4–xF-42 (x=0.05–0.3, weight ratio) membranes were investigated for the first time. Thin flexible membranes for x≥0.15 with the uniform distribution of the components were obtained by a tape casting method. Mechanical properties of the membranes were measured by Vickers microhardness tests for a low polymer content (x˂0.15), also the tensile strength for membranes with high polymer content x=0.2–0.3 were evaluated. Proton conductivity of the (1–x)CsH2PO4–xpF-42 composite polymer electrolytes decreases monotonically with increasing x due to the effect of a «conductor-insulator» percolation. The combination of conductivity, mechanical strength and hydrophobic properties of (1–x)CsH2PO4–xF-42 makes certain compositions of proton-conducting membranes (x~0.2–0.25) promising for their use in intermediate-temperature fuel cells, despite decreased conductivity.


proton conductivity; cesium dihydrogen phosphate; fluoropolymer; p(VDF/TFE); tape casting

Full Text:



Haile SM, Chisholm CRI, Sasaki K, Boysen DA, Uda T. Solid acid proton conductors: from laboratory curiosities to fuel cell electrolytes. Faraday Discuss. 2007;134:17-39. doi:10.1039/B604311A

Uda T, Haile SM. Electrochem. Thin-membrane solid-acid fuel cell. Solid State Lett. 2005;8:A245. doi:10.1149/1.1883874

Ponomareva V, Bagryantseva I, Zakharov B, Bulina N, Lavrova G, Boldyreva E. Crystal structure and proton conductivity of a new Cs3(H2PO4)(HPO4)·2H2O phase in the caesium di- and monohydrogen orthophosphate system. Acta Cryst. 2017;C73:773–779. doi:10.1107/S2053229617012335

Sanghvi S, Haile SM. Crystal structure, conductivity, and phase stability of Cs3(H1.5PO4)2 under controlled humidity. Solid State Ionics. 2020;349:115291. doi:10.1016/j.ssi.2020.115291

Weil M, Stöger B. The caesium phosphates Cs3(H1.5PO4)2(H2O)2, Cs3(H1.5PO4)2, Cs4P2O7(H2O)4, and CsPO3 MonatsheftefürChemie – Chemical Monthly. 2020;151:1317–1328. doi:10.1007/s00706-020-02675-6

Wang LS, Patel SV, Sanghvi SS, Hu YY, Haile SM. Structure and Properties of Cs7(H4PO4)(H2PO4)8: A New Superprotonic Solid Acid Featuring the Unusual Polycation (H4PO4)+. JACS. 2020;142(47):19992–20001. doi:10.1021/jacs.0c08870

Baranov AI, Khiznichenko VP, Sandler VA, Shuvalov LA. Frequency Dielectric Dispersion in the Ferroelectric and Superionic Phases of CsH2PO4. Ferroelectrics. 1988;81:1147–1150. doi:10.1080/00150198808008840

Boysen DA, Uda T, Chisholm CRI, Haile SM. High-performance solid acid fuel cells through humidity stabili-zation. Sci. 2004;303:68–70. doi:10.1126/science.109092

Taninouchi Y, Uda T, AwakuraY, Ikeda A, Haile SM. Dehydration behavior of the superprotonic conductor CsH2PO4 at moderate temperatures: 230 to 260 °С. J Mater Chem. 2007;17:3182–3189. doi:10.1039/B704558C

Qing G, Kikuchi R, Takagaki A, Sugawara T, Oyama ST. CsH2PO4/polyvinylidene fluoride composite electrolytes for intermediate temperature fuel cells. J Electrochem Soc. 2014;161:451–457. doi:10.1149/2.052404jes

Xie Q, Li Y, Hu J, Chen X, Li H. A CsH2PO4-based composite electrolyte membrane for intermediate temperature fuel cells. J Membrane Sci. 2015;489:98–105. doi:10.1016/j.memsci.2015.03.083

Qing G, Kikuchi R, Takagaki A, Sugawara T, Oyama ST. CsH2PO4/epoxy composite electrolytes for intermediate temperature fuel cells. Electrochim Acta. 2015;169:219–226. doi:10.1016/j.electacta.2015.04.089

Bagryantseva IN, Gaydamaka AA, Ponomareva VG. Interme-diate temperature proton electrolytes based on cesium dihydrogen phosphate and Butvar polymer. Ionics. 2020;26:1813–1818. doi:10.1007/s11581-020-03505-9

Bagryantseva IN, Ponomareva VG, Lazareva NP. Proton-conductive membranes based on CsH2PO4 and ultradispersed polytetrafluoroethylene. Solid State Ionics. 2019;329:61–66. doi:10.1016/j.ssi.2018.11.010

Bagryantseva IN, Ponomareva VG, Khusnutdinov VR. In-termediate temperature proton electrolytes based on cesium dihydrogen phosphate and poly (vinylidene fluoride-cohexafluoropropylene). J Materi Sci. 2021;56(25):14196–14206. doi:10.1007/s10853-021-06137-0

Navarrete L, Yoo CY, Serra JM. Comparative study of epoxy‐CsH2PO4 composite electrolytes and porous metal based electrocatalysts for solid acid electrochemical cells. Membranes. 2021;11:196. doi:10.3390/membranes11030196

Koch EC. Metal-fluorocarbon based energetic materials. Wiley-VCH Verlag GmbH & Co. KGaA;Germany, 2012. P. 360.

Drobny JG. Technology of fluoropolymers. Taylor & Francis Group:LLC:Boca Raton;2009.248.

Ameduri B. From vinylidene fluoride (VDF) to the applications of vdf-containing polymers and copolymers: recent developments and future trends. Chem Rev. 2009;109:6632–6686. doi:10.1021/cr800187m

Lovinger AJ, Davis DD, Cais RE, Kometani JM. Compositional variation of the structure and solid-state transformations of vinylidene fluoride/tetrafluoroethylene copolymers. Macromolec. 1988;21:78–83. doi:10.1021/ma00179a017


Copyright (c) 2022 Irina N. Bagryantseva, Yuri E. Kungurtsev, Valentina G. Ponomareva

Scopus logo WorldCat logo DOAJ logo CAS logo BASE logo eLibrary logo

Chimica Techno Acta, 2014-2022
ISSN 2411-1414 (Online)