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Thermal barrier coating (TBC) materials employ ceramics with low thermal conductivity and excellent thermal durability. Recently, the gas turbine market has been increasing demand for a thermally insulating material applicable at higher operating temperatures above 1200 °C for greater thermal conversion efficiency. In this study, synthesized high-entropy A 2 Zr 2 O 7 zirconate ceramics incorporated five cations of a similar ionic radius into the A3+ cation site through a conventional solid-state reaction, and their superior thermophysical properties demonstrate. The HEO ceramics exhibited overall low thermal conductivity (from room temperature to 1000 °C) due to inducing lattice distortion in the crystal structure. In addition, divalent cations were added to the A3+ cation site to increase the oxygen vacancy at the structure, thereby suppressing the heat transfer caused by phonon. A 2 Zr 2 O 7 zirconate HEOs show enhanced thermal barrier performance than yttria-stabilized zirconia (YSZ), conventional TBC material, demonstrating a possibility of application as next-generation TBC materials. [ABSTRACT FROM AUTHOR]

In this study, a high-entropy approach was employed to design a new single-phase A 2 B 2 O 7 oxide for thermal insulation applications. Multicomponent high-entropy oxides, containing up to seven different cations, were successfully synthesized in a single defective fluorite structure. We observed that the incorporation of the functional cation, Zn2+, effectively blocked the heat radiation phenomenon by reducing the photon mean free path, and further reduced the high-temperature thermal conductivity owing to the larger free carrier concentration originated from the large number of oxygen vacancies. Although a large concentration of Zn2+ caused a slight reduction in thermal expansion, this study suggests that functional cations can be easily incorporated; thus, expanding the material diversity beyond the typical doping levels to develop new thermal barrier materials. [ABSTRACT FROM AUTHOR]

Stretchable devices significantly expand the scope of applications such as flexible displays and wearable devices/sensors. To enable stretchable wearable electronics, methods for connecting unit devices and developing circuits are required. Previously, research was performed to manufacture circuits with 3D structures or patterns that remain intact when the flexible and stretchable substrates are deformed. A method for drawing a circuit directly on a substrate with a conductive ink pen is proposed, although it is limited by the surface properties of the substrate. Most existing transparent papers are not sufficiently stretchable for flexible and wearable electronics applications. Therefore, a polydimethylsiloxane–cellulose nanocrystals (PDMS–CNC) composite paper is developed that is both highly flexible and stretchable, while maintaining a high transmittance. The versatility of the composite paper is demonstrated as a suitable substrate for flexible devices by patterning with a conductive ink pen. The PDMS–CNC composite paper has an excellent transmittance of ≈70%, and can withstand over 800% tensile strain. The patterned circuits have only minor increase in resistance after a 50% deformation and recovery. The composite paper is a suitable technology for fabricating electrical components and devices for the Internet of Things and wearable and flexible electronics applications. [ABSTRACT FROM AUTHOR]

The effects of substituting the B cation in A3BO7 ceramics on their thermal physical properties were investigated by applying a large mass difference. Y3(Nb1‐xTax)O7 (x = 0, 0.1, 0.2, 0.3, 0.4, and 0.5) ceramics were synthesized, and their structural characteristics were determined. All the fabricated Y3(Nb1‐xTax)O7 ceramics showed defective fluorite structures and glass‐like low thermal conductivity (1.18−2.04 W/m∙K at 25°C) because of the highly distorted crystal structure and significant mass difference. Substitution with Ta5+ enhanced the sintering resistance, leading to superior thermal‐insulating performance via grain boundary scattering. Furthermore, the ceramics exhibited excellent coefficients of thermal expansion, implying the promising applicability of Y3(Nb1‐xTax)O7 as new thermal barrier materials. The effect of mass difference on the thermomechanical properties of the ceramics was examined, suggesting a simple strategy for engineering the chemical composition of new thermal barrier materials. [ABSTRACT FROM AUTHOR]

Proton conducting fuel cells (PCFCs) are considered as promising energy generation system due to their possibility for lowering the operation temperature. PCFCs operated at low temperature by conducting small and light protons, which enables stable operation without undesirable side reactions by thermal corrosion. However, kinetic energy for redox reaction at electrodes is insufficient due to the decreased operating temperature, resulting in degraded electrochemical performance. In this study, by forming BaCo 0·4 Fe 0·4 Zr 0·1 Y 0·1 O 3-δ (BCFZY), a triple conducting material which could conduct proton, oxygen ions, and electrons at the electrodes, the power generation performance of PCFCs has been improved dramatically. BCFZY nanoparticles provide a charge passage, and effectively expand the reaction site. A proton conducting fuel cells with electrodes containing BCFZY exhibit an enhanced power density of 1.06 W cm−2 at 650 °C, which is almost 3 times higher value than the cell without formation of BCFZY on the electrodes. Our study proposes an effective strategy for enhancing the performance PCFCs by facilitating the conduction of charge carriers within the electrodes through applying BCFZY triple conductor. • The triple conducting material is applied on both electrodes for PCFC. • The triple conductor expands reaction region by increasing the passage of charge. • PCFCs with BCFZY exhibited significant improvements in power density. • Almost 3 times higher power density is shown for the cell with BCFZY. • Stable working without any degradation is confirmed for 100 h. [ABSTRACT FROM AUTHOR]

The styrene-butadiene rubber (SBR) binder migration caused by the capillary force-driven solvent evaporation during the drying process results in the concentration gradient of SBR binder in the anode, which deteriorates the adhesion strength at the interface between the anode film and Cu current collector and Li-ion kinetics, respectively. Here, we report SBR patterned Cu current collector (SPC) to overcome problems caused by the SBR binder migration behavior. Pre-patterned SBR strongly adheres to the Cu current collector, which suppresses its migration during the drying process. Homogeneous SBR distribution in the longitudinal direction of the anode improves the adhesion strength and Li-ion kinetics. Enhanced adhesion strength enables the reduction of the SBR content in the anode, which further improves Li-ion kinetics. The anode employing SPC exhibits improved constant current charging capacity retention and cycling stability compared to those of the anode with a pristine Cu current collector. • Highly adhesive SBR patterned Cu (SPC) was prepared by facile bar-coating process. • SPC enables homogeneous SBR distribution in the anode. • SPC improves adhesion strength and Li-ion kinetics in the anode. • Enhanced adhesion strength reduces SBR content in the anode, improving kinetics. • The anode employing SPC exhibits improved electrochemical properties. [ABSTRACT FROM AUTHOR]