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.

2021 F. M. Becket Fellowship – Summary Report Measuring Transient Electrochemistry of Lithium Metal Anodes under Varying External Stack Pressures

Lithium metal anodes are challenged by the inherent chemical and electrochemical reactivity of lithium metal, which is further exacerbated by non-uniform high surface area deposition. Recently, lithium difluoro(oxalato)borate (LiDFOB) salt coupled with a fluorinated solvent has been demonstrated to result in densely deposited lithium morphology along with high Coulombic efficiencies due to a stable solidelectrolyte-interphase. Along with other newly discovered electrolyte compositions for stable lithium deposition, these studies typically utilize high stack pressures and elevated temperatures. These developments are promising, and would further benefit from a study that maps out the effects of varying stack pressure and temperature on lithium anode mechanics, chemistry, and electrochemistry.

Sulfur and phosphorus co-doped nickel–cobalt layered double hydroxides for enhancing electrochemical reactivity and supercapacitor performance

The optimized sulfur and phosphorus co-doped NiCo LDH reduces charge transfer resistance and realizes efficient redox reaction, achieving an outstanding specific capacitance of 3844.8 F g−1 at 3 A g−1.

Micro-area investigation on electrochemical performance improvement with Co and Mn doping in PbO2 electrode materials

The causes of the increase in electrochemical reactivity are unveiled from a micro perspective through scanning electrochemical microscopy.