Role of Fe Impurity Reactions in the Electrochemical Properties of MgFeBO.

We investigate magnesium-iron pyroborate MgFeBO as a potential cathode material for rechargeable magnesium-ion batteries. Synchrotron powder X-ray diffraction and Mössbauer spectroscopy confirm its successful synthesis and iron stabilization in the high-spin Fe(II) state. Initial electrochemical testing against a lithium metal anode yields a first charge capacity near the theoretical value (147.

SrMnONaSe: A Metamagnetic Layered Oxychalcogenide Synthesized by Reductive Na Intercalation to Break [Se] Perselenide Dimer Units.

Recent advances in anion-redox topochemistry have enabled the synthesis of metastable mixed-anion solids. Synthesis of the new transition metal oxychalcogenide SrMnONaSe by topochemical Na intercalation into SrMnOSe is reported here. Na intercalation is enabled by the redox activity of [Se] perselenide dimers, where the Se-Se bonds are cleaved and a [Na Se] antifluorite layer is formed.

Microstructures of layered Ni-rich cathodes for lithium-ion batteries.

Millions of electric vehicles (EVs) on the road are powered by lithium-ion batteries (LIBs) based on nickel-rich layered oxide (NRLO) cathodes, and they suffer from a limited driving range and safety concerns. Increasing the Ni content is a key way to boost the energy densities of LIBs and alleviate the EV range anxiety, which are, however, compromised by the rapid performance fading. One unique challenge lies in the worsening of the microstructural stability with a rising Ni-content in the cathode.

Controlling the Superconductivity of NbPdS via Reversible Li Intercalation.

The NbPdS ( ≈ 0.74) superconductor with a of 6.5 K is reduced by the intercalation of lithium in ammonia solution or electrochemically to produce an intercalated phase with expanded lattice parameters.

Anion redox as a means to derive layered manganese oxychalcogenides with exotic intergrowth structures.

Topochemistry enables step-by-step conversions of solid-state materials often leading to metastable structures that retain initial structural motifs. Recent advances in this field revealed many examples where relatively bulky anionic constituents were actively involved in redox reactions during (de)intercalation processes. Such reactions are often accompanied by anion-anion bond formation, which heralds possibilities to design novel structure types disparate from known precursors, in a controlled manner.

Synthesis and Characterization of Magnesium Vanadates as Potential Magnesium-Ion Cathode Materials through an Ab Initio Guided Carbothermal Reduction Approach.

Many technologically relevant materials for advanced energy storage and catalysis feature reduced transition-metal (TM) oxides that are often nontrivial to prepare because of the need to control the reducing nature of the atmosphere in which they are synthesized. Herein, we show that an ab initio predictive synthesis strategy can be used to produce multi-gram-scale products of various MgV O -type phases (δ-MgV O , spinel MgV O , and MgVO ) containing V or V relevant for Mg-ion battery cathodes. Characterization of these phases using Mg solid-state NMR spectroscopy illustrates the potential of Mg NMR for studying reversible magnesiation and local charge distributions.

Toward an Understanding of SEI Formation and Lithium Plating on Copper in Anode-Free Batteries.

"Anode-free" batteries present a significant advantage due to their substantially higher energy density and ease of assembly in a dry air atmosphere. However, issues involving lithium dendrite growth and low cycling Coulombic efficiencies during operation remain to be solved. Solid electrolyte interphase (SEI) formation on Cu and its effect on Li plating are studied here to understand the interplay between the Cu current collector surface chemistry and plated Li morphology.

Structural Evolution of Layered Manganese Oxysulfides during Reversible Electrochemical Lithium Insertion and Copper Extrusion.

The electrochemical lithiation and delithiation of the layered oxysulfide SrMnOCuS has been investigated by using a combination of powder X-ray diffraction and neutron powder diffraction, X-ray absorption and Li NMR spectroscopy, together with a range of electrochemical experiments. SrMnOCuS consists of [SrMnO] perovskite-type cationic layers alternating with highly defective antifluorite-type [CuS] (δ ≈ 0.5) anionic layers.

Exploring Cation-Anion Redox Processes in One-Dimensional Linear Chain Vanadium Tetrasulfide Rechargeable Magnesium Ion Cathodes.

For magnesium ion batteries (MIBs) to be used commercially, new cathodes must be developed that show stable reversible Mg intercalation. VS is one such promising material, with vanadium and disulfide anions [S] forming one-dimensional linear chains, with a large interchain spacing (5.83 Å) enabling reversible Mg insertion.

Effects of Atmospheric Gases on Li Metal Cyclability and Solid-Electrolyte Interphase Formation.

For Li-air batteries, dissolved gas can cross over from the air electrode to the Li metal anode and affect the solid-electrolyte interphase (SEI) formation, a phenomenon that has not been fully characterized. In this work, the impact of atmospheric gases on the SEI properties is studied using electrochemical methods and ex situ characterization techniques, including X-ray photoelectron spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. The presence of O significantly improved the lithium cyclability; less lithium is consumed to form the SEI or is lost because of electrical disconnects.

Solar thermochemical splitting of water to generate hydrogen.

Solar photochemical means of splitting water (artificial photosynthesis) to generate hydrogen is emerging as a viable process. The solar thermochemical route also promises to be an attractive means of achieving this objective. In this paper we present different types of thermochemical cycles that one can use for the purpose.

Beneficial effects of substituting trivalent ions in the B-site of La0.5Sr0.5Mn1-xAxO3 (A = Al, Ga, Sc) on the thermochemical generation of CO and H2 from CO2 and H2O.

The effect of substitution of Al(3+), Ga(3+) and Sc(3+) ions in the Mn(3+) site of La0.5Sr0.5MnO3 on the thermochemical splitting of CO2 to generate CO has been studied in detail.

Solar photochemical and thermochemical splitting of water.

Artificial photosynthesis to carry out both the oxidation and the reduction of water has emerged to be an exciting area of research. It has been possible to photochemically generate oxygen by using a scheme similar to the Z-scheme, by using suitable catalysts in place of water-oxidation catalyst in the Z-scheme in natural photosynthesis. The best oxidation catalysts are found to be Co and Mn oxides with the e(1) g configuration.

Ln0.5 A0.5 MnO3 (Ln=Lanthanide, A= Ca, Sr) Perovskites Exhibiting Remarkable Performance in the Thermochemical Generation of CO and H2 from CO2 and H2 O.

Perovskite oxides of the Ln0.5 A0.5 MnO3 (Ln=lanthanide, A=Sr, Ca) family have been investigated for the thermochemical splitting of H2 O and CO2 to produce H2 and CO respectively.

Noteworthy performance of La(1-x)Ca(x)MnO3 perovskites in generating H2 and CO by the thermochemical splitting of H2O and CO2.

Perovskite oxides of the composition La1-xCaxMnO3 (LCM) have been investigated for the thermochemical splitting of H2O and CO2 to produce H2 and CO, respectively. The study was carried out in comparison with La1-xSrxMnO3, CeO2 and other oxides. The LCM system exhibits superior characteristics in high-temperature evolution of oxygen, and in reducing CO2 to CO and H2O to H2.

Synthesis and antibacterial and antifungal evaluation of some chalcone based sulfones and bisulfones.

Two series of chalcone based sulfone and bisulfone derivatives were synthesized using chalcone, thiophenol and sodium metal at room temperature, followed by oxidation of chalcone sulfides with m-CPBA at 0 °C in a novel method. Both sulfones and bisulfones were evaluated for their antimicrobial activities against Aspergillus niger and Candida albicans (yeast), Bacillus subtilis and Staphylococcus aureus (Gram (+) bacteria) and Pseudomonas aeruginosa and Salmonella typhimurium (Gram (-) bacteria) strains. Among them, compounds 2c, 3c, 6c, 7c, 8c and 9c have shown high antifungal activity against C.