Directing SEI formation on Si-based electrodes using atomic layer deposition.

The design of artificial solid eletroctrolyte interphase is an important task to minimize capacity losses in Li-ion batteries. Herein, TiO created through atomic layer deposition was used as an artificial SEI on Si nanoparticles. Such coating led to substantial improvement of cycling stability when evaluated with FEC-free electrolyte.

Improved electrochemical performance and solid electrolyte interphase properties of electrolytes based on lithium bis(fluorosulfonyl)imide for high content silicon anodes.

Electrodes containing 60 wt% micron-sized silicon were investigated with electrolytes containing carbonate solvents and either LiPF or lithium bis(fluorosulfonyl)imide (LiFSI) salt. The electrodes showed improved performance, with respect to capacity, cycling stability, rate performance, electrode resistance and cycle life with the LiFSI salt, attributed to differences in the solid electrolyte interphase (SEI). Through impedance spectroscopy, cross sectional analysis using transmission electron microscopy (TEM) and focused ion beam (FIB) in combination with scanning electron microscopy (SEM), and electrode surface characterization by X-ray photoelectron spectroscopy (XPS), differences in electrode morphological changes, SEI composition and local distribution of SEI components were investigated.

Stoichiometry-Controlled Reversible Lithiation Capacity in Nanostructured Silicon Nitrides Enabled by Conversion Reaction.

In modern Li-based batteries, alloying anode materials have the potential to drastically improve the volumetric and specific energy storage capacity. For the past decade silicon has been viewed as a "Holy Grail" among these materials; however, severe stability issues limit its potential. Herein, we present amorphous substoichiometric silicon nitride (SiN) as a convertible anode material, which allows overcoming the stability challenges associated with common alloying materials.

Pre-hospital critical care management of severe hypoxemia in victims of Covid-19: a case series.

Objective: Despite critical hypoxemia, Covid-19 patients may present without proportional signs of respiratory distress. We report three patients with critical respiratory failure due to Covid-19, in which all presented with severe hypoxemia refractory to supplemental oxygen therapy. We discuss possible strategies for ventilatory support in the emergency pre-hospital setting, and point out some pitfalls regarding the management of these patients.