Formation Processes of a Solid Electrolyte Interphase at a Silicon/Sulfide Electrolyte Interface in a Model All-Solid-State Li-Ion Battery.

Understanding the electrochemical reactions at the interface between a Si anode and a solid sulfide electrolyte is essential in improving the cycle stabilities of Si anodes in all-solid-state batteries (ASSBs). Highly dense Si films with very low roughnesses of <1 nm were fabricated at room temperature via cathodic arc plasma deposition, which led to the formation of a Si/sulfide electrolyte model interface. Li (de)alloying through the model interface hardly occurred during the first cycle, whereas it proceeded stably in subsequent cycles.

Selective Synthesis of Perovskite Oxyhydrides Using a High-Pressure Flux Method.

Oxyhydrides with multi-anions (O and H) are a recently developed material family and have attracted attention as catalysts and hydride ion conductors. High-pressure and high-temperature reactions are effective in synthesizing oxyhydrides, but the reactions sometimes result in inhomogeneous products due to insufficient diffusion of the solid components. Here, we synthesized new perovskite oxyhydrides SrVOH and SrVOH.

A lithium superionic conductor for millimeter-thick battery electrode.

No design rules have yet been established for producing solid electrolytes with a lithium-ion conductivity high enough to replace liquid electrolytes and expand the performance and battery configuration limits of current lithium ion batteries. Taking advantage of the properties of high-entropy materials, we have designed a highly ion-conductive solid electrolyte by increasing the compositional complexity of a known lithium superionic conductor to eliminate ion migration barriers while maintaining the structural framework for superionic conduction. The synthesized phase with a compositional complexity showed an improved ion conductivity.

Anomalously High Ionic Conductivity of LiSiS-Type Conductors.

Solid-state electrolytes that exhibit high ionic conductivities at room temperature are key materials for obtaining the next generation of safer, higher-specific-energy solid-state batteries. However, the number of currently available crystal structures for use as superionic conductors remains limited. Here, we report a lithium superionic conductor, LiSiS, with tetragonal crystal symmetry, which possesses a new three-dimensional framework structure consisting of isolated edge-sharing tetrahedral dimers.

LiGePS-Type Structured Solid Solution Phases in the LiPSO System: Controlling Crystallinity by Synthesis to Improve the Air Stability.

Understanding the fast Li ionic conductors of oxygen-substituted thiophosphates is useful for developing all-solid-state batteries because these compounds possess a high electrochemical stability and thus may be applied as solid electrolytes. In this study, we synthesized the LiPSO series of solid solution phases with the same structure as the LiGePS superionic conductor and characterized their crystallinity, solid solution range, and chemical stabilities. Two methods (mechanochemical and melt quenching) were used for sample synthesis.

[Evaluation of mental stress tests among medical students based on salivary sample collected just before the national license examination].

We investigated salivary amylase (sAMY) and chromogranin A (sCgA) in students before the national license examination in order to investigate the relationship between stress biomarkers and the Profile of Mood States (POMS) psychological test. Fifty-one medical students that provided informed consent were tested for sAMY activity and sCgA concentration by means of the amylase monitor method (NIPRO) and an ELISA kit (Yanaihara), respectively. The POMS psychology test (shortened form) was purchased from Chiba Test Center, and all students fully answered the lifestyle questionnaires.