Insights on microstructural evolution and capacity fade on diatom [Formula: see text] anodes for lithium-ion batteries.

[Formula: see text] is a promising material for developing high-capacity anodes for lithium-ion batteries (LIBs). However, microstructural changes of [Formula: see text] anodes at the particle and electrode level upon prolonged cycling remains unclear. In this work, the causes leading to capacity fade on [Formula: see text] anodes were investigated and simple strategies to attenuate anode degradation were explored.

Nanostructured diatom earth SiO negative electrodes with superior electrochemical performance for lithium ion batteries.

Diatomaceous earth (DE) is a naturally occurring silica source constituted by fossilized remains of diatoms, a type of hard-shelled algae, which exhibits a complex hierarchically nanostructured porous silica network. In this work, we analyze the positive effects of reducing DE SiO particles to the sub-micrometer level and implementing an optimized carbon coating treatment to obtain DE SiO anodes with superior electrochemical performance for Li-ion batteries. Pristine DE with an average particle size of 17 μm is able to deliver a specific capacity of 575 mA h g after 100 cycles at a constant current of 100 mA g, and reducing the particle size to 470 nm enhanced the reversible specific capacity to 740 mA h g.

Time-Resolved Synchrotron Powder X-ray Diffraction Studies on the Synthesis of LiSiO and Its Reaction with CO.

Lithium oxosilicate was synthesized via the solid-state method using LiO and SiO as starting reactants. In situ synchrotron powder X-ray diffraction (SPRXD) coupled with Rietveld refinement allowed describing the synthesis as a two-step process where LiO and SiO react to form LiSiO and, at higher temperatures, lithium orthosilicate reacts with the remaining LiO to form LiSiO. Time-resolved measurements allowed determining the temperatures at which each phase transformation occurs as well as the time required to complete the synthesis.

Isotope Labeling Reveals Fast Atomic and Molecular Exchange in Mechanochemical Milling Reactions.

Using tandem in situ monitoring and isotope-labeled solids, we reveal that mechanochemical ball-milling overcomes inherently slow solid-state diffusion through continuous comminution and growth of milled particles. This process occurs with or without a net chemical reaction and also occurs between solids and liquid additives that can be practically used for highly efficient deuterium labeling of solids. The presented findings reveal a fundamental aspect of milling reactions and also delineate a methodology that should be considered in the study of mechanochemical reaction mechanisms.

Tandem In Situ Monitoring for Quantitative Assessment of Mechanochemical Reactions Involving Structurally Unknown Phases.

We report herein quantitative in situ monitoring by simultaneous PXRD and Raman spectroscopy of the mechanochemical reaction between benzoic acid and nicotinamide, affording a rich polymorphic system with four new cocrystal polymorphs, multiple phase transformations, and a variety of reaction pathways. After observing polymorphs by in situ monitoring, we were able to isolate and characterize three of the four polymorphs, most of which are not accessible from solution. Relative stabilities among the isolated polymorphs at ambient conditions were established by slurry experiments.