Unraveling the Synergistic Effect of Mg and Ti Codoping to Realize an Ordered Structure and Excellent Performance for Sodium-Ion Batteries.

Layered cathodes have been recognized as potential advanced candidates for sodium-ion batteries (SIBs), but the poor electrochemical performance has seriously hindered their further development. Herein, an ordered Na[NiMgMnTi]O (NMMT) is designed and investigated as a high-performance cathode for SIBs through the synergistic effect of Mg and Ti codoping. Compared to the single Mg- or Ti-doped materials, NMMT clearly exhibits superstructure ordering diffraction peaks, and neutron diffraction further confirms that the diffraction peaks can be well indexed by a larger supercell 6, rather than the common unit cell 6/ by X-ray diffraction (XRD).

The first- and second-order isothermal phase transitions in FeGa-type compounds.

Structural features and kinetics of the transition between ordered metastable b.c.c.

Electronic Structures of the Vanadium-Intercalated and Substitutionally Doped Transition-Metal Dichalcogenides TiVSe.

The electronic structures of V-intercalated TiSe and substitutionally doped dichalcogenides TiVSe have been studied using soft X-ray photoelectron, resonant photoelectron, and absorption spectroscopies. In the case of the substitution of Ti by V, the formation of coherently oriented structural fragments VSe and TiSe is observed and a small charge transfer between these fragments is found. Intercalation of the V atoms into TiSe leads to charge transfer from the V atoms to the Ti atoms with the formation of covalent complexes Ti-Se-V-Se-Ti.