Protonated state and synergistic role of Nd3+ doped barium cerate perovskite for the enhancement of ionic pathways in novel sulfonated polyethersulfone for H2/O2 fuel cells

Abstract

In recent decades, there has been a need for novel advancement of sustainable non-fluorinated polymer electrolyte membranes for proton exchange membrane fuel cell (PEMFC) applications. The set forth strategy aims to ameliorate proton conduction of sulfonated polyethersulfone (SPES) polymer membranes with a distinct mixture of barium cerate (BCO) and neodymium-doped barium cerate (BCNO) perovskites developing cationic composite membranes (CCMs) prepared through a technique of solvent casting. The CCMs were subjected to analysis of their mechanical, structural, chemical compositional, thermal, morphological, oxidative, physicochemical, electrochemical and fuel cell polarization performance respectively. Acceptor doping of the trivalent neodymium group at the B site of BCO increases the number of oxygen vacancies and improves ionic conduction. The CCM of neodymium-doped barium cerate demonstrates a higher proton conductivity of 42.2 mS cm⁻¹ with a lower activation energy of 6.80 kJ mol⁻¹ at 80 °C. The maximum current density and power density with the OCV of 0.93 V for the neodymium-doped barium cerate membrane are 397 mA cm⁻² and 117 mW cm⁻², which is 1.8 times greater than that of the pure SPES membrane. On the basis of polarization performance, the SPES membrane with neodymium-doped barium cerate has great potential in highly-efficient PEMFC applications.