Iodide Double Perovskites and the Limits of their Structural Stability.

While halide double perovskites AM(I)M(III)X have attracted significant attention, examples involving iodides are rare. We examine the limits of the structural stability of iodide double perovskites, presenting the synthesis and single-crystal structures of CsNaScI and CsNaYI. Bypassing the common expectation that iodides have small band gaps, these compounds display optical gaps of 3.

Molecular Origins of Near-Infrared Luminescence in Molybdenum and Tungsten Oxyhalide Perovskites.

Materials with near-infrared (near-IR) luminescence are desirable for applications in communications and sensing, as well as biomedical diagnostics and imaging. The most used inorganic near-IR emitters rely on precise doping of host crystal structures with select rare-earth or transition metal ions. Recently, another class of materials with intrinsic near-IR emission has been reported.

Structural Evolution in Disordered Rock Salt Cathodes.

Li-excess Mn-based disordered rock salt oxides (DRX) are promising Li-ion cathode materials owing to their cost-effectiveness and high theoretical capacities. It has recently been shown that Mn-rich DRX LiMnMO ( ≥ 0.5, M are hypervalent ions such as Ti and Nb) exhibit a gradual capacity increase during the first few charge-discharge cycles, which coincides with the emergence of spinel-like domains within the long-range DRX structure coined as "δ phase".

Composition and Structure of the solid electrolyte interphase on Na-Ion Anodes Revealed by Exo- and Endogenous Dynamic Nuclear Polarization─NMR Spectroscopy.

Sodium ion batteries (SIB) are among the most promising devices for large scale energy storage. Their stable and long-term performance depends on the formation of the solid electrolyte interphase (SEI), a nanosized, heterogeneous and disordered layer, formed due to degradation of the electrolyte at the anode surface. The chemical and structural properties of the SEI control the charge transfer process at the electrode-electrolyte interface, thus, there is great interest in determining these properties for understanding, and ultimately controlling, SEI functionality.