The performance of Cell-Batt Li-ion cells and Sony 18650 cells using non-stoichiometric spinel and LiCoO2, respectively, as positive electrode material has been studied under several modes of charging. During cycling, the cells were opened at intermittent cycles and extensive material and electrochemical characterization was done on the active material at both electrodes. Capacity fade of spine...

Introduction: Grain size separate CG from the Murray CM2 carbonaceous chondrite contains mostly spinel grains of average diameter 0.5 μm [1]. Zinner et al. [2] found that approximately 1% of these spinel grains are of presolar origin as determined by their large O isotopic anomalies. These O isotopic measurements were made with the NanoSIMS on individual grains that were well separated from one...

The mechanical properties (fracture strength, fracture toughness, and Vickers microhardness) of MgAl2O4 and x wt% ZrO2–MgAl2O4 (1 # x # 30) hot-pressed materials were measured at room temperature. Two kinds of materials, which were prepared from either ball-milled or attrited powders, were investigated. Compared with an unreinforced spinel, a twofold (or greater) increase in both strengthening ...

The A2BO4 spinel oxides are distinguished by having either a normal (N) or an inverse (I) distribution of the A, B cations on their sublattices. A point-ion electrostatic model parametrized by the oxygen displacement parameter u and by the relative cation valencies Z{A} vs Z{B} provides a simple rule for the structural preference for N or I: if Z{A}>Z{B} the structure is normal for u>0.2592 and...

Quaternary compounds AB 2 X 3 Y (A = Cu, Ag ; B = In ; X = S, Se, Te ; Y = Cl, Br, I) could be synthesized at high pressures and temperatures. The crystal structures found are defect-zincblende (AgIn2Se3l, AgIn2Te3l, CuIn2Se3Br, CuIn2Se3I, CuIn2Te3Cl, CuIn2Te3Br, CuInTesI), spinel (AgIn2S3Cl, AgIn2S3Br, AgIn2Se3Cl, AgIn2Se3Br, AgIn2Se3l) and defectrocksalt (AgIn2Te3Cl, AgIn2Te3Br). A second for...

The influence of prolonged ball milling on structural changes of hexagonal and spinel type complex iron oxides has been studied by x-ray diffraction and high resolution electron microscopy. The XRD and HREM results for ball milled SrFel2Olg ferrite show fast decomposition and formation of Fe203 and SrO simple oxides. Microstructural developments for a powder mixture of Co(OH)2 and Fe203 show th...

In recent years, the research on supercapacitors has ushered in an explosive growth, which mainly focuses on seeking nano-/micro-materials with high energy and power densities. Herein, this review will be arranged from three aspects. We will summarize the controllable architectures of spinel NiCo₂O₄ fabricated by various approaches. Then, we introduce their performances as supercapacitors due t...

An in-situ Raman spectroscopic study was conducted to explore the pressure induced phase transformation of spinel-type ferrite ZnFe2O4. Results indicate that ferrite ZnFe2O4 initially transforms to an orthorhombic structure phase (CaFe2O4polymorph) at a pressure of 24.6 GPa. Such a phase transformation is complete at 34.2 GPa, and continuously remains stable to the peak pressure of 61.9 GPa. Th...

Correction for 'An acid-free rechargeable battery based on PbSO4 and spinel LiMn2O4' by Yu Liu et al., Chem. Commun., 2014, 50, 13714-13717.