Two-dimensional dumbbell silicene as a promising anode material for(Li/Na/K)-ion batteries

Rechargeable ion batteries require anode materials with excellent performance,presenting a key challenge for researchers.This paper explores the potential of using two-dimensional dumbbell silicene as an anode material for alkali metal ion batteries through density functional theory(DFT)calculations.Our findings demonstrate that alkali metal ions have negative adsorption energies on dumbbell silicene,and the energy barriers for Li/Na/K ion diffusion are as low as0.032 e V/0.055 e V/0.21 e V,indicating that metal ions can easily diffuse across the entire surface of dumbbell silicene.Additionally,the average open circuit voltages of dumbbell silicene as anode for Li-ion,Na-ion,and K-ion batteries are 0.42 V,0.41 V,and 0.60 V,respectively,with corresponding storage capacities of 716 m Ah/g,622 m Ah/g,and 716 m Ah/g.These results suggest that dumbbell silicene is an ideal anode material for Li-ion,Na-ion,and K-ion batteries,with high capacity,low open circuit voltage,and high ion diffusion kinetics.Moreover,our calculations show that the theoretical capacities obtained using DFT-D2 are higher than those obtained using DFT-D3,providing a valuable reference for subsequent theoretical calculations.

Fabrication and growth mechanism of one-dimensional Heusler alloy nanostructures with different morphologies on anodic aluminum oxide template by magnetron sputtering

Heusler alloys are a kind of intermetallic compounds with highly-ordered arrangement of atoms.Many attractive functional materials have been developed in Heusler alloys.Due to the application requirements of materials in new-generation electronic devices and spintronics devices,one-dimensional nanostructured Heusler alloys with special functions are needed.In this work,it is proposed to grow one-dimensional Heusler alloy nanostructures(1D-HA-NSs)by magnetron sputtering plus anodic aluminum oxide(AAO)template.Nanowires with different shapes,amorphous-coated(AC)nanowires and nanotubes were successfully grown for several Heusler alloys.AC nanowires are the unique products of our method.Heusler alloy nanotubes are reported for the first time.The one-dimensional nanostructures grow on the surface of the AAO substrate rather than in the holes.The top of the pore wall is the nanostructure growth point,the shape of which determines the morphology of the nanostructures.A general growth mechanism model of one-dimensional nanostructures on AAO template was established and further confirmed by experimental observation.