Multilayered Co₃O₄/NiO/C electrodes with a ball-in-ball hollow morphology are employed in lithium-ion batteries and deliver an excellent rate capacity of 421 mA h g⁻¹ at 4 A g⁻¹ and a high capacity of 776 mA h g⁻¹ over 1000 cycles at 1 A g⁻¹.

It is difficult to obtain a single-phase environmental barrier coating material that simultaneously offers the advantages of low thermal conductivity, a suitable coefficient of thermal expansion, and excellent corrosion resistance. Herein, to synthesize the advantages of single-phase materials, we have developed an effective approach for the design of high-entropy multiphase ceramics of rare earth oxides and silicates. Such a specific design approach is capable of making high-entropy RE₂SiO₅/RE₂O₃ and RE₂SiO₅/RE₂Si₂O₇ (RE = Lu, Yb, Tm, Er, Ho, and Y) multiphase ceramics as two types of potential environmental barrier coating materials for Al₂O_3f/Al₂O₃ and SiC_f/SiC ceramic matrix composites.

In this paper, the effect of microstructure on the thermal conductivity of plasma-sprayed Y₂O₃ stabilized ZrO₂ (YSZ) thermal barrier coatings (TBCs) is investigated. Nine freestanding samples deposited on aluminum alloys are studied. Cross-section morphology such as pores, cracks, m-phase content, grain boundary density of the coated samples are examined by scanning electron microscopy (SEM) and electron back-scattered diffraction (EBSD). Multiple linear regressions are used to develop quantitative models that describe the relationship between the particle parameters, m-phase content and features of the microstructure such as porosity, crack-porosity, and the length density of small and big angle-cracks. Moreover, the relationship between the microstructure and thermal conductivity is investigated. Results reveal that the thermal conductivity of the coating is mainly determined by the microstructure and grain boundary density at room temperature (25 °C), and by the length density of big-angle-crack, monoclinic phase content and grain boundary density at high temperature (1200 °C).

For decreasing the global cost of corrosion, it is essential to understand the intricate mechanisms of corrosion and enhance the corrosion resistance of materials. However, the ambiguity surrounding the dominant mechanism of calcium‐magnesium aluminosilicate (CMAS) molten salt corrosion in extreme environments hinders the mix‐and‐matching of the key rare earth elements for increasing the resistance of monosilicates against corrosion of CMAS. Herein, an approach based on correlated electron microscopy techniques combined with density functional theory calculations is presented to elucidate the complex interplay of competing mechanisms that control the corrosion of CMAS of monosilicates. These findings reveal a competition between thermodynamics and kinetics that relies on the temperatures and corrosion processes. Innovative medium‐entropy monosilicates with exceptional corrosion resistance even at 1500 °C are developed. This is achieved by precisely modulating the radii of rare earth ions in monosilicates to strike a delicate balance between the competition in thermodynamics and kinetics. After 50 and 100 h of corrosion, the thinnest reactive layers are measured to be only 28.8 and 35.4 µm, respectively.

Spatial resolution is one of the key factors in orientation microscopy, as it determines the accuracy of grain size investigation and phase identification. We determined the spatial resolutions of on-axis and off-axis transmission Kikuchi diffraction (TKD) methods by calculating correlation coefficients using only the effective parts of on-axis and off-axis transmission Kikuchi patterns. During the calculation, we used average filtering to evaluate the spatial resolution more accurately. The spatial resolutions of both on-axis and off-axis TKD methods were determined in the same scanning electron microscope at different accelerating voltages and specimen thicknesses. The spatial resolution of the on-axis TKD was higher than that of the off-axis TKD at the same parameters. Furthermore, with an increase in accelerating voltage or a decrease in specimen thickness, the spatial resolutions of the two configurations could be significantly improved, from tens of nanometers to below 10 nm. At a voltage of 30 kV and sample thickness of 74 nm, both on-axis and off-axis TKD methods exhibited the highest resolutions of 6.2 and 9.7 nm, respectively.