Local and Bulk Probe of Vanadium-Substituted α-Manganese Oxide (α-KVMnO) Lithium Electrochemistry.

A series of V-substituted α-MnO (KMnVO·HO, = 0, 0.2, 0.34, 0.

(De)lithiation of spinel ferrites FeO, MgFeO, and ZnFeO: a combined spectroscopic, diffraction and theory study.

Iron based materials hold promise as next generation battery electrode materials for Li ion batteries due to their earth abundance, low cost, and low environmental impact. The iron oxide, magnetite Fe3O4, adopts the spinel (AB2O4) structure. Other 2+ cation transition metal centers can also occupy both tetrahedral and/or octahedral sites in the spinel structure including MgFe2O4, a partially inverse spinel, and ZnFe2O4, a normal spinel.

Solution-Based, Anion-Doping of Li Ti O Nanoflowers for Lithium-Ion Battery Applications.

Solution-based, anionic doping represents a convenient strategy with which to improve upon the conductivity of candidate anode materials such as Li Ti O (LTO). As such, novel synthetic hydrothermally-inspired protocols have primarily been devised herein, aimed at the large-scale production of unique halogen-doped, micron-scale, three-dimensional, hierarchical LTO flower-like motifs. Although fluorine (F) doping has been explored, the use of chlorine (Cl) dopants is the primary focus here.

Vanadium-Substituted Tunnel Structured Silver Hollandite (AgVMnO): Impact on Morphology and Electrochemistry.

A series of tunnel structured V-substituted silver hollandite (AgVMnO, = 0-1.4) samples is prepared and characterized through a combination of synchrotron X-ray diffraction (XRD), synchrotron X-ray absorption spectroscopy (XAS), laboratory Raman spectroscopy, and electron microscopy measurements. The oxidation states of the individual transition metals are characterized using V and Mn K-edge XAS data indicating the vanadium centers exist as V, and the Mn oxidation state decreases with increased V substitution to balance the charge.

Evaporation-Induced Vertical Alignment Enabling Directional Ion Transport in a 2D-Nanosheet-Based Battery Electrode.

2D nanosheets have been widely explored as electrode materials owing to their extraordinarily high electrochemical activity and fast solid-state diffusion. However, the scalable electrode fabrication based on this type of material usually suffers from severe performance losses due to restricted ion-transport kinetics in a large thickness. Here, a novel strategy based on evaporation-induced assembly to enable directional ion transport via forming vertically aligned nanosheets is reported.

Defect Control in the Synthesis of 2 D MoS Nanosheets: Polysulfide Trapping in Composite Sulfur Cathodes for Li-S Batteries.

One of the inherent challenges with Li-S batteries is polysulfide dissolution, in which soluble polysulfide species can contribute to the active material loss from the cathode and undergo shuttling reactions inhibiting the ability to effectively charge the battery. Prior theoretical studies have proposed the possible benefit of defective 2 D MoS materials as polysulfide trapping agents. Herein the synthesis and thorough characterization of hydrothermally prepared MoS nanosheets that vary in layer number, morphology, lateral size, and defect content are reported.