The aim of this critical review is to provide a broad but digestible overview of mechanochemical synthesis, i.e. reactions conducted by grinding solid reactants together with no or minimal solvent. Although mechanochemistry has historically been a sideline approach to synthesis it may soon move into the mainstream because it is increasingly apparent that it can be practical, and even advantageous, and because of the opportunities it provides for developing more sustainable methods. Concentrating on recent advances, this article covers industrial aspects, inorganic materials, organic synthesis, cocrystallisation, pharmaceutical aspects, metal complexes (including metal–organic frameworks), supramolecular aspects and characterization methods. The historical development, mechanistic aspects, limitations and opportunities are also discussed (314 references).

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Mechanochemistry: opportunities for new and cleaner synthesis

Ceramic and polymeric solid electrolytes for lithium-ion batteries

Future generations of electrified vehicles require driving ranges of at least 300 miles to successfully penetrate the mass consumer market. A significant improvement in the energy density of lithium batteries is mandatory, maintaining at the same time similar, or improved, rate capability, lifetime, cost, and safety. Several new cathode materials have been claimed over the last decade to allow for this energy improvement. The possibility that some of them will find application in the future automotive batteries is critically evaluated here by first considering their theoretical and experimentally demonstrated energy densities at the material level. For selected candidates, the energy density at the automotive battery cell level for electric vehicle applications is calculated using an in-house developed software. For the selected cathodes, literature results concerning their power capability and lifetime are also discussed with reference to the automotive targets.

Future generations of cathode materials: an automotive industry perspective

https://escholarship.org/content/qt3mb3d98h/qt3mb3d98h.pdf?t=qobip7

Computational Screening of Cathode Coatings for Solid-State Batteries

Conservation agriculture is an approach to management of agro-ecosystems for improved and sustainable productivity, thereby conserving natural resources and the environment. It uses minimal soil disturbance (no tillage) and permanent soil cover (mulch) as sustainable cultivation practices for the future. In Algeria, conservation agriculture was introduced only about 10 years ago. In this study, plough tillage (PT), reduced tillage (RT) and no-till (NT) were evaluated regarding their effects on physical, chemical and microbiological soil parameters in an on-farm research approach in two agricultural regions of Algeria (Annaba and Sétif) with differing site and agricultural soil management conditions. Soil samples were taken from fields on commercial farms, at Annaba on soils containing mainly recent clayey alluvium in a Mediterranean climate and at Sétif on soils with limestone rock parent material and a semi-arid continental Mediterranean climate. The interactions between soil structural properties and microbial biomass and activities were examined using disturbed and undisturbed soil samples collected on two occasions from the top 20 cm of soil in all three tillage systems. The results showed a generally intensive loosening effect of PT compared with RT and NT, which led to lower bulk density and higher porosity. The parameters macroporosity and air permeability demonstrated that the air-filled pore space in the topsoil differed in its transport efficiency between the tillage systems, with rather random organisation in PT and RT and a more continuous arrangement in NT. Structural stability of the topsoil layer and its resistance to compaction was inversely correlated with tillage loosening intensity. The content of tot-C and tot-N showed significant correlations between in the two regions and all tillage systems. Comparable differences between tillage systems and regions for tot-C and the C/N ratio in the entire set of samples suggest that more input of new, litter-derived organic matter with large C/N ratios promotes larger tot-C concentrations in the study two site. These results of C/N ratio indicate that we have a good mineralization of the SOM in RT, NT and PT successively for the two regions, but in Annaba, it was good and fast on the surface and takes a slow regime at depth, but the Sétif mineralization was slow and only returns a small amount of mineral nitrogen to the soil. Two microbiological parameters, biomass and basal respiration, were positively affected by RT and showed a distinct effect of sampling date, with the highest values observed shortly after tillage. Site-specific effects were also observed. Based on the results, it was not possible to identify an ideal tillage system associated with only positive effects on soil quality parameters, but it seems to be the TCS have been identified as an optimal tillage system for the regions studied. These preliminary results from on-farm research are of a tentative nature and must be confirmed in further studies in order to deliver reliable recommendations for farmers in Algeria.

I. Introduction générale

The electrical conductivity of NaNO3–xAl2O3 composites has been studied over the wide range of temperature and frequency by means of impedance spectroscopy. The real part of the frequency dependent conductivity exhibits a simple power law feature and the dimensionless frequency exponent n has been determined. The conductivity spectra show scaling behaviour when the conductivity spectra are scaled by σdcT, where T is temperature in Kelvin. The real part of dielectric permittivity shows saturation at higher frequencies and a strong dispersion at lower frequencies. The imaginary part of permittivity varies inversely with frequency, due to the presence of dc conductivity. The frequency dependent plots of M″ and Z″ show that the conductivity relaxation is non-Debye in nature. The Kohlrausch-Williams-Watts stretched exponential function was used to describe the modulus spectra and the stretching exponent β is found to be temperature independent. The conductivity relaxation time has been estimated from the modulus spectra. The activation energy responsible for relaxation has been evaluated and it was found to be almost same as that of dc conductivity.

K. Hariharan

Papers

ac Conductivity analysis and dielectric relaxation behaviour of NaNO3–Al2O3 composites

Ionic transport studies on (PEO)6:NaPO3 polymer electrolyte plasticized with PEG400

Physical and ionic transport studies on poly(ethylene oxide)–NaNO3 polymer electrolyte system

AC conductivity and scaling studies of polycrystalline SnF2

Sodium ion transport in NaPO3-Na2SO4 glasses