Vanadium oxides (VO x ) have been extensively investigated over the past years as promising electrode materials for alkali ion batteries owing to their rich and interesting electrochemical properties. Further improvements on electrochemistry of VO x materials have been possible by working at the nanoscale as well as by realising hierarchical composites with various carbon allotropes. However, the nanocomposite synthesis methods are not always efficient, nor green, requiring either expensive precursors, extended synthesis time or harmful reagents. Herein, we report on rapid and environmentally friendly synthesis methods of a library of VO x @rGO composites via impregnation and hydrothermal protocols using a cheap and commercially available V 2 O 5 precursor. Different oxidation states, crystalline phases and nanoscale morphologies can be reproducibly accessed and their physico-chemical properties have been characterized. The electrochemical properties (lithium and sodium ion storage) of the synthesized VO x @rGO nanocomposites and phases have been critically inter-compared between these but also with respect to commercial (CM) VO x -based electrodes. Whereas nanostructuring is found to impact the power-rate performances, the amount of stored charge and the cycling stability are sensitively dependent on the cycling potential window, while being minorly affected by the morphology and synthesis method. The composites are also found to exhibit different electrochemistry for sodium storage, with more sloping potential profiles. Peculiarly, the synthesized V 2 O 3 @rGO composite shows no signs of electrochemical activity pointing towards the electrochemical inertness of this particular V 2 O 3 composite and phase. This work could serve as reference for future developments on this class of important battery materials as it is one of the few studies describing a comprehensive and comparative study of several different influential parameters on the electrochemical behaviour of vanadium oxides in different oxidation states, crystalline phases and morphologies.

With the emergence of quality by design in the pharmaceutical industry, it becomes imperative to gain a deeper mechanistic understanding of factors impacting the flow of a formulation into tableting dies. Many flow characterization techniques are present, but so far only a few have shown to mimic the die filling process successfully. One of the challenges in mimicking the die filling process is the impact of rheological powder behavior as a result of differences in flow field in the feeding frame. In the current study, the rheological behavior was investigated for a wide range of excipients with a wide range of material properties. A new parameter for rheological behavior was introduced, which is a measure for the change in dynamic cohesive index upon changes in flow field. Particle size distribution was identified as a main contributing factor to the rheological behavior of powders. The presence of fines between larger particles turned out to reduce the rheological index, which the authors explain by improved particle separation at more dynamic flow fields. This study also revealed that obtained insights on rheological behavior can be used to optimize agitator settings in a tableting machine.

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