Solving the polysulfide shuttle problem is one of the core challenges for industrialization of lithium-sulfur batteries. In this work, a triphasic composite of layered double hydroxide (LDH)/sulfur/reduced graphene oxide with a crepe cake like structure is designed and fabricated as a positive electrode material for lithium-sulfur batteries. Sulfur nanoparticles are embedded in the interlayer space of the composite, and thus are well protected physically via three-dimensional wrapping and chemically via strong interaction of LDH nanoflakes with lithium polysulfides, such as ionic bonds and S-H hydrogen bonds. In addition, the flexible lamellar structure of the composite with soft graphene layers can tolerate the volume expansion of sulfur during lithiation as well as facilitate ionic permeability and electron transport, which is favorable for the redox reactions of polysulfide. The present work shed light on the future development and industrialization of lithium-sulfur batteries.

CaCO 3 spherulites were found in the myostracum layer of common limpet shells collected from East Sands, St Andrews, Scotland. Their microstructures were revealed by using powder X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, and energy dispersive X-ray microanalysis. The formation mechanisms of these spherulites and their morphology evolution were postulated. It was proposed that spherical particles of an inorganic and biological composite formed first. In the centre of each spherical particle a double-layer disk of vaterite crystal sandwiching a biological sheet developed. The disk crystal supplies a relatively strong mirror symmetric dipole field, guiding the orientations of the nanocrystallites and the arrangement of mesorods and, therefore, determining the final morphology of the spherulite.

The oxygen electrode with a fast oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and sufficient durability plays a pivotal role in reversible solid oxide cells (RSOCs). Here, we demonstrate a NdBa 0.5 Ca 0.5 Co 1.5 Fe 0.5 O 5+δ @ Gd 0.1 Ce 0.9 O 2−δ (NBCCF@GDC) composite oxygen electrode via a one-pot method for exhibiting strong coherency, which result in boosting the electrochemical performance of RSOCs. The NBCCF@GDC electrode yields a very low polarization resistance (0.106 Ω-cm 2 at 800 °C), high electrolysis current density (1.45 A cm −2 with 70 vol % absolute humidity at 1.3 V), and high power density (∼1.3 W cm −2 at 800 °C) and shows excellent reversibility and stability. Notably, strong coherency in these NBCCF@GDC composite materials was successfully revealed by HT-XRD, XPS, STEM, and EELS. The phase contiguity and interfacial coherence between NBCCF and GDC increase the Co oxidation state and the number of active sites, which enhanced the electrocatalytic activity for perovskites. Overall, this work demonstrates a highly desirable strategy for the production of functionalized electrodes for next-generation reversible solid oxide cells.

The layered perovskite LaTaO 4 has been synthesized to be stable in both (polar) orthorhombic and (nonpolar) monoclinic polymorphs at ambient conditions. Although the structural transition between monoclinic and orthorhombic phases has been well established, there is some controversy regarding a further, unidentified transition around 500 K. Here this is identified as an incommensurate-commensurate first-order transition between incommensurate Cmc2 1 (α00)0s0 and commensurate Cmc2 1 orthorhombic phases. Transmission electron microscopy indicates partially ordered stacking of different structural units in a, identifying the local cause for the modulation, whereas variable temperature powder neutron diffraction has shown the overall macroscopic modulation vector, q ≈ (0.456, 0, 0)-roughly a 2.2 × expansion in a, corresponding to an approximate 11a commensurate superunit cell dimension. The modulation shows a continuous temperature dependence until transitioning to the basic (commensurate) cell at T IC-C. Doping the interlayer La sites with smaller Nd cations stabilizes the incommensuration to higher temperature, suggesting the modulation is geometrically driven at the A site.

Naturally occurring calcite spherulitic particles were collected from East Kirkton Quarry in Bathgate, Scotland. Their microstructure has been revealed, by using XRD, EDX, SEM and HRTEM, to consist of a low crystallinity core with deposition of multilayer radially oriented calcite microrods. The surrounding materials of the spherulites are mainly Ca-free silicates. To understand the formation mechanism of this construction of calcite crystals, biomimetic synthesis of similar spherulites have been carried out by using alginate and stevensite as structure directing agents. It is found that alginate is essential for growth of the spherulites, since the spherulites are developed only when they are embedded in the alginate network, a soft matter substrate. Stevensite also plays an important role of adjusting the hardness of the alginate substrate, offering a suitable network for the self-aggregation and self-orientation of the calcite nanocrystals. Possible inter-particle interactions or driving force of the particle aggregation and self-orientation are discussed.