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To enhance the energy density of Li‐ion batteries, high‐capacity and high‐voltage cathode materials are needed. Recently, Ni‐rich layered oxides have attracted attention as they can offer ≈200 mAh g−1 when cycled up to 4.3 V. However, cycling these materials in their full capacity range often leads to excessive reactivity with the electrolyte, resulting in particle cracking, transition metal dissolution, and oxygen loss. In this study, the use of lithium hydridoaluminates as electrolyte additives is explored for lithium‐ion batteries based on nickel‐rich cathode materials. Being mild reducing agents, these additives act as HF scavengers, avoiding transition metal dissolution from the cathode. Additionally, their oxidation results in the formation of an Al‐rich protective layer on the cathode, which dampens the surface reactivity, preventing surface reconstruction and impedance build‐up. This study further stresses the important role of the cathode‐electrolyte interface phenomena on the capacity degradation of Ni‐rich cathode materials and provides a novel avenue for controlling this reactivity, thus extending their cycling life. [ABSTRACT FROM AUTHOR]

Li(Ni0.80Co0.15Al0.05)O2 is a lithium-ion battery cathode, commercially available for more than twenty years, which is associated with high energy capacity and high energy density, with moderate power. Atomic layer fluorination (ALF) of Li(Ni0.80Co0.15Al0.05)O2 with XeF2 is performed to improve its cyclability. The ALF method aims at forming an efficient protecting fluorinated layer at the surface of the material, with a low fluorine content. Surface fluorinated Li(Ni0.80Co0.15Al0.05)O2 is characterized by X-ray diffraction, electron microscopy, 19F nuclear magnetic resonance, X-ray photoelectron spectroscopy, and galvanostatic measurements, and a fluorine content as low as 1.4 wt% is found. The presence of fluorine atoms improves the electrochemical performances of Li(Ni0.80Co0.15Al0.05)O2: cyclability, polarization and rate capability are improved. Operando infrared spectroscopy and post-mortem gas chromatography provide some insights into the origins of these improvements. [ABSTRACT FROM AUTHOR]

The self-diffusion properties of butyl-methyl-imidazolium bis(trifluoromethylsulfonyl)-imide {[BMM][TFSI]} water system are examined. Results suggest an increase in the self-diffusion coefficient of every species with the quantity of water.

It is possible that 131Xe multiple-quantum filtered NMR will prove an effective method for characterizing the surface state of low-density aerogels. It may be possible to probe for a range of materials that are adsorbed on the surface.

Solid‐state batteries are enjoying a regained interest owing to the discovery of sulfide‐based solid electrolytes with ionic conductivities comparable to their liquid counterparts. Among them, the metastable β‐Li3PS4 polymorph has attracted great attention given its high room temperature ionic conductivity (≈0.15 mS cm−1) when synthesized via a solvent‐mediated route. However, the origin of such a high conductivity together with its structural interplay remains unclear. Herein, an in‐depth study of the THF‐synthesized nanoporous β‐Li3PS4 is reported. Synchrotron X‐ray diffraction, NMR, and Raman spectroscopy confirm the presence of β‐Li3PS4 as the only crystalline phase and also reveal an additional amorphous phase and remnant THF. Moreover, a clear dependence of the ionic conductivity of the material on the relative content of its phases is found, the amorphous one being the most conductive. Lastly, high chemical reactivity is found for the nanoporous β‐Li3PS4 and other phosphosulfide electrolytes toward Li metal, evidenced in the spontaneous ignition when mixed together and further investigated by XRD and XPS. This study, which unveils a hidden side of the THF‐synthesized β‐Li3PS4 and other sulfide solid electrolytes, provides a new insight to the battery community when selecting a proper electrolyte for practical all‐solid state batteries. [ABSTRACT FROM AUTHOR]