Effect of Temperature on Intermediate Phases of NaV(PO) during Cycling by X-ray Diffraction.

NaV(PO) (NVP) has gained a lot of attention due to its remarkable properties, such as its robust crystal structure, cycle life, rate capabilities, and so on. Nevertheless, NVP undergoes a substantial decrease in its rate capability at low temperatures, which limits its practical applications. In this study, the performance of NVP at low, room, and high temperatures during cycling is thoroughly investigated using synchrotron X-ray diffraction.

The Impact of Intergrain Phases on the Ionic Conductivity of the LAGP Solid Electrolyte Material Prepared by Spark Plasma Sintering.

LiAlGe(PO) (LAGP) is a promising oxide solid electrolyte for all-solid-state batteries due to its excellent air stability, acceptable electrochemical stability window, and cost-effective precursor materials. However, further improvement in the ionic conductivity performance of oxide solid-state electrolytes is hindered by the presence of grain boundaries and their associated morphologies and composition. These key factors thus represent a major obstacle to the improved design of modern oxide based solid-state electrolytes.

Fundamental investigations on the sodium-ion transport properties of mixed polyanion solid-state battery electrolytes.

Lithium and sodium (Na) mixed polyanion solid electrolytes for all-solid-state batteries display some of the highest ionic conductivities reported to date. However, the effect of polyanion mixing on the ion-transport properties is still not fully understood. Here, we focus on NaZrSiPO (0 ≤ x ≤ 3) NASICON electrolyte to elucidate the role of polyanion mixing on the Na-ion transport properties.

Si and Ge-Based Anode Materials for Li-, Na-, and K-Ion Batteries: A Perspective from Structure to Electrochemical Mechanism.

Silicon and germanium are among the most promising candidates as anodes for Li-ion batteries, meanwhile their potential application in sodium- and potassium-ion batteries is emerging. The access of their entire potential requires a comprehensive understanding of their electrochemical mechanism. This Review highlights the processes taking place during the alloying reaction of Si and Ge with the alkali ions.

Structural and Mechanistic Insights into Fast Lithium-Ion Conduction in Li4SiO4-Li3PO4 Solid Electrolytes.

Solid electrolytes that are chemically stable and have a high ionic conductivity would dramatically enhance the safety and operating lifespan of rechargeable lithium batteries. Here, we apply a multi-technique approach to the Li-ion conducting system (1-z)Li4SiO4-(z)Li3PO4 with the aim of developing a solid electrolyte with enhanced ionic conductivity. Previously unidentified superstructure and immiscibility features in high-purity samples are characterized by X-ray and neutron diffraction across a range of compositions (z = 0.

Resolving the different silicon clusters in Li12Si7 by 29Si and (6,7)Li solid-state NMR spectroscopy.

Structural signatures: The analysis of Si-Si and Si-Li connectivities by solid-state NMR spectroscopy allows the different types of silicon clusters to be discriminated in the model lithium silicide compound Li(12)Si(7) (see picture, Si clusters red and blue, Li ions gray). The results provide new NMR spectroscopic strategies with which to differentiate and study the structures formed in silicon-based electrode materials.

Second-order optical nonlinearity and ionic conductivity of nanocrystalline GeS2-Ga2S3-LiI glass-ceramics with improved thermo-mechanical properties.

IR-transparent chalcogenide glass-ceramics were fabricated through a careful ceramization process of the as-prepared 65 GeS(2) x 25 Ga(2)S(3) x 10 LiI glasses at a temperature of 403 degrees C for various durations. Owing to the precipitation of Li(x)Ga(y)S(z) crystals with a Ga(2)S(3)-like structure, clear second-harmonic generation was observed in the sample crystallized at 403 degrees C for 60 h, which has a greatly improved resistance to environmental impairment. Additionally, it is found that the shorter crystallization process (< or = 60 h) contributed to the enhancement of Li(+) ionic conductivity, whereas a longer heat-treatment (80 h) would impair that of the glass-ceramics.

Real-time NMR investigations of structural changes in silicon electrodes for lithium-ion batteries.

Lithium-ion batteries (LIBs) containing silicon negative electrodes have been the subject of much recent investigation because of the extremely large gravimetric and volumetric capacity of silicon. The crystalline-to-amorphous phase transition that occurs on electrochemical Li insertion into crystalline Si, during the first discharge, hinders attempts to link structure in these systems with electrochemical performance. We apply a combination of static, in situ and magic angle sample spinning, ex situ (7)Li nuclear magnetic resonance (NMR) studies to investigate the changes in local structure that occur in an actual working LIB.