TY - JOUR

T1 - Electrochemical characterization of novel polyantimonic-acid-based proton conductors for low-and intermediate-temperature fuel cells

AU - Kurapova, Olga Yu

AU - Faia, Pedro M.

AU - Zaripov, Artem A.

AU - Pazheltsev, Vasily V.

AU - Glukharev, Artem A.

AU - Konakov, Vladimir G.

N1 - Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

PY - 2021/12/1

Y1 - 2021/12/1

N2 - The development of novel proton-conducting membrane materials for electrochemical power units, i.e., low temperature fuel cells (FCs), efficiently working up to 300◦C, is a critical problem related to the rapid shift to hydrogen energy. Polyantimonic acid (PAA) is characterized by high conductivity, sufficient thermal stability and can be regarded as a prospective proton-conducting material. However, the fabrication of bulk PAA-based membranes with high proton conductivity remains a challenging task. In the present work, for the first time, the authors report the investigation on proton conductivity of bulk PAA-based membranes in the temperature range 25–250◦C, both in dry air and in moisturized air. Using PAA powder and fluoroplastic as a binder, fully dense cylindrical membranes were formed by cold uniaxial pressing. The structures of the PAA-based membranes were investigated by SEM, EDX, XRD and Raman techniques. STA coupled with in situ thermo-XRD analysis revealed that the obtained membranes corresponded with Sb2O5·3H2O with pyrochlore structure, and that no phase transitions took place up to 330◦C. PAA-based membranes possess a high-grain component of conductivity, 5 × 10−2 S/cm. Grain boundary conductivities of 90PAA and 80PAA membranes increase with relative humidity content and their values change non-linearly in the range 25–250◦C.

AB - The development of novel proton-conducting membrane materials for electrochemical power units, i.e., low temperature fuel cells (FCs), efficiently working up to 300◦C, is a critical problem related to the rapid shift to hydrogen energy. Polyantimonic acid (PAA) is characterized by high conductivity, sufficient thermal stability and can be regarded as a prospective proton-conducting material. However, the fabrication of bulk PAA-based membranes with high proton conductivity remains a challenging task. In the present work, for the first time, the authors report the investigation on proton conductivity of bulk PAA-based membranes in the temperature range 25–250◦C, both in dry air and in moisturized air. Using PAA powder and fluoroplastic as a binder, fully dense cylindrical membranes were formed by cold uniaxial pressing. The structures of the PAA-based membranes were investigated by SEM, EDX, XRD and Raman techniques. STA coupled with in situ thermo-XRD analysis revealed that the obtained membranes corresponded with Sb2O5·3H2O with pyrochlore structure, and that no phase transitions took place up to 330◦C. PAA-based membranes possess a high-grain component of conductivity, 5 × 10−2 S/cm. Grain boundary conductivities of 90PAA and 80PAA membranes increase with relative humidity content and their values change non-linearly in the range 25–250◦C.

KW - Impedance spectroscopy

KW - Ion-conducting membranes

KW - Polyantimonic acid

KW - Proton conductivity

UR - http://www.scopus.com/inward/record.url?scp=85121233744&partnerID=8YFLogxK

U2 - 10.3390/app112411877

DO - 10.3390/app112411877

M3 - Article

AN - SCOPUS:85121233744

VL - 11

JO - Applied Sciences (Switzerland)

JF - Applied Sciences (Switzerland)

SN - 2076-3417

IS - 24

M1 - 11877

ER -