Unveiling the Magnesium Storage Mechanisms of Co-Sputtered Indium-Tin Alloy Films Using Operando X-ray Diffraction

Tin (Sn)-based anodes have drawn extensive attention for magnesium ion batteries (MIBs) owing to their low reaction potentials, high theoretical capacities, and compatibility with conventional electrolytes. However, their poor electrochemical reactivity, sluggish kinetics, and large volume changes have obstructed progresses. Additionally, a clear understanding of the Mg storage chemistry is crucial for the development of high-performance MIBs. Here, we prepared self-supporting In-Sn alloy films with different compositions and phase constitutions via a one-step magnetron co-sputtering. As benchmarked with pure Sn film, the single-phase and biphase In-Sn alloy films effectively trigger the alloying reaction of Sn with Mg and further increasing of In significantly improves the electrochemical reactivity of the In-Sn electrodes. More importantly, operando X-ray diffraction was performed to unveil the magnesiation/demagnesiation mechanisms of the In0.2Sn0.8, In0.2Sn0.8/In3Sn and In3Sn electrodes, showing that In0.2Sn0.8 and In3Sn display different Mg storage mechanisms when existing alone or biphase coexisting. Our findings highlight the significance of the electrode design and mechanism investigations for MIBs.

Influences of silicon carbide nanowires addition on IMC growth behavior of pure Sn solder during solid-liquid diffusion

In this paper, various mass fraction (0, 0.2, 0.4, 0.6, 0.8, 1.0 wt%) of silicon carbide nanowires (SiC) were incorporated into pure Sn solder to enhance the performances of Sn solder joint. The wetting behavior, shear strength and intermetallic compound (IMC) growth mechanism of Sn-xSiC/Cu solder during solid-liquid diffusion at 250°C was investigated systematically. The experiment results demonstrated that the wettability of Sn-xSiC/Cu solder had a significant improvement when the addition of SiC was up to 0.6 wt%, and excessive additives would degrade the wettability of the composite solder. The formation of the Cu6Sn5 IMC layer was observed at the Sn-xSiC solder/Cu interface. Meanwhile, SiC as an additive was conducive to restraining the growth of interfacial IMC during soldering process and the IMC thickness overtly fell down after doping 0.8 wt% SiC into Sn solder. Moreover, SiC addition would contribute to enhancing the mechanical performance of Sn solder joint. The fracture mechanism of solder joint changed from a mix of brittle and ductile fracture to a characteristic of typical ductile fracture.

Tuning the transition barrier of H2 dissociation in the hydrogenation of CO2 to formic acid on Ti-doped Sn2O4 clusters

Schematic representation of Ti-doping on a pure Sn2O4 cluster for the hydrogenation of CO2 to HCOOH via a hydride pathway.

Modelling of Void Collapse with Molecular Dynamics in Pure Sn

This work simulates the collapse of a spherical void in pure Sn during melting using molecular dynamics (MD). Simulations were performed for two temperatures with a modified embedded atom method (MEAM) potential, which was reported to be in good agreement with respect to melting point and elastic constants. Solutions of the Rayleigh–Plesset (RP) equation are used for comparison under the assumption of macroscopic surface tension and liquid viscosity. Despite a qualitative correlation, longer collapse times were observed in MD simulations, which arose from partial solid structures and the incubation time for melting.

The Effects of Trace Sb and Zn Additions on Cu6Sn5 Lithium-Ion Battery Anodes

Sn-based compounds are promising candidates for application as anodes in lithium-ion batteries (LIBs) due to the favourable storage capacity of Sn at 993 mAh g−1 compared to carbon at 372 mAh g−1. The use of Sn-based anodes also avoids some of the safety concerns associated with carbon anodes. However, the large volume changes during lithiation and delithiation of pure Sn anodes often results in poor cyclic performance. Alloying Sn with Cu, an element inactive with respect to Li, buffers the expansion stresses and can improve cycling performance. Cu6Sn5 is therefore a promising candidate anode material. In this work, the effects of Sb and Zn additions on the morphology, crystal structure, atomic arrangements and the electrochemical performance of the anodes were evaluated. Characterisation with synchrotron X-ray powder diffraction and Cs-corrected transmission electron microscopy revealed the larger lattice parameters, higher symmetry crystal structures and well-ordered atomic arrangements in the Sb and Zn modified electrodes, which resulted in a more than 50% increase in cycling capacity from 490 mAh g−1 to 760 mAh g−1.