Dual-ion electrolytes with oxygen ion and proton-conducting properties are among the innovative solid oxide electrolytes, which exhibit a low Ohmic resistance at temperatures below 550 °C. Ba-Co 0.4 Fe 0.4 Zr 0.1 Y 0.1 O 3−δ with a perovskite-phase cathode has demonstrated efficient triple-charge conduction (H + /O 2− /e − ) in a high-performance lowtemperature solid oxide fuel cell (LT-SOFC). Here, we designed another type of triple-charge conducting perovskite oxide based on Ba 0.5 Sr 0.5 Co 0.1 Fe 0.7 Zr 0.1 Y 0.1 O 3−δ (BSCFZY), which formed a heterostructure with ionic conductor Ca 0.04 Ce 0.80 Sm 0.16 O 2−δ (SCDC), showing both a high ionic conductivity of 0.22 S cm −1 and an excellent power output of 900 mW cm −2 in a hybrid-ion LT-SOFC. In addition to demonstrating that a heterostructure BSCFZY−SCDC can be a good functional electrolyte, the existence of hybrid H + /O 2− conducting species in BSCFZY−SCDC was confirmed. The heterointerface formation between BSCFZY and SCDC can be explained by energy band alignment, which was verified through UV−vis spectroscopy and UV photoelectron spectroscopy (UPS). The interface may help in providing a pathway to enhance the ionic conductivities and to avoid short-circuiting. Various characterization techniques are used to probe the electrochemical and physical properties of the material containing dual-ion characteristics. The results indicate that the triple-charge conducting electrolyte is a potential candidate to further reduce the operating temperature of SOFC while simultaneously maintaining high performance. KEYWORDS: triple-charge conduction, Ba 0.5 Sr 0.5 Co 0.1 Fe 0.7 Zr 0.1 Y 0.1 O 3−δ (BSCFZY) perovskite, semiconductor−ion heterostructure, Schottky junction, dual-ion conductivity, band alignment

Achieving fast ionic conductivity in the electrolyte at low operating temperatures while maintaining the stable and high electrochemical performance of solid oxide fuel cells (SOFCs) is challenging. Herein, we propose a new type of electrolyte based on perovskite Sr0.5Pr0.5Fe0.4Ti0.6O3−δ for low-temperature SOFCs. The ionic conducting behavior of the electrolyte is modulated using Mg doping, and three different Sr0.5Pr0.5Fe0.4–x Mg x Ti0.6O3−δ (x = 0, 0.1, and 0.2) samples are prepared. The synthesized Sr0.5Pr0.5Fe0.2Mg0.2Ti0.6O3−δ (SPFMg0.2T) proved to be an optimal electrolyte material, exhibiting a high ionic conductivity of 0.133 S cm–1 along with an attractive fuel cell performance of 0.83 W cm–2 at 520 °C. We proved that a proper amount of Mg doping (20%) contributes to the creation of an adequate number of oxygen vacancies, which facilitates the fast transport of the oxide ions. Considering its rapid oxide ion transport, the prepared SPFMg0.2T presented heterostructure characteristics in the form of an insulating core and superionic conduction via surface layers. In addition, the effect of Mg doping is intensively investigated to tune the band structure for the transport of charged species. Meanwhile, the concept of energy band alignment is employed to interpret the working principle of the proposed electrolyte. Moreover, the density functional theory is utilized to determine the perovskite structures of SrTiO3−δ and Sr0.5Pr0.5Fe0.4–x Mg x Ti0.6O3−δ (x = 0, 0.1, and 0.2) and their electronic states. Further, the SPFMg0.2T with 20% Mg doping exhibited low dissociation energy, which ensures the fast and high ionic conduction in the electrolyte. Inclusively, Sr0.5Pr0.5Fe0.4Ti0.6O3−δ is a promising electrolyte for SOFCs, and its performance can be efficiently boosted via Mg doping to modulate the energy band structure.

MWCNTs–MnO2 anodes and MWCNTs–MoO3 cathodes were screen printed on carbon nanoparticle flexible electrodes for supercapacitor applications.

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Neutron diffraction measurements were performed on single-crystal samples to study the nature of the exotic order phase of CeOs4Sb12 below the transition temperature 0.9 K. An antiferromagnetic ordering with propagation vector q = (1 0 0), and a tiny moment is determined as the magnetic ground state. Our neutron data provide direct evidence for a spin-density-wave (SDW) ground state as first proposed by Yogi et al.