[15p-K509-1~7] 13.1 Fundamental properties, surface and interface, and simulations of Si related materials

1:45 PM - 2:00 PM JST(4:45 AM - 5:00 AM UTC)

[15p-K509-2] First-principles study on diffusion mechanism of Li ion in Si—Ge heterostructure

〇Kenichi Koizumi¹, Yoshiteru Kono¹ (1.Tokuyama Corporation)

Keywords:

Li-ion battery,Si-Ge heterostructure,First-principles calculation

Silicon is currently attracting attention as a candidate for anode materials that can increase the capacity of lithium-ion secondary batteries (LiBs). However, LiBs using silicon as the anode active material are not yet practical in terms of battery characteristics, and there is room for improvement. We have found that adding germanium to silicon improves the battery characteristics of charge/discharge efficiency and overvoltage suppression. Because the lattice constant of germanium is larger than that of silicon, it may be believed that lattice distortion exists at the silicon-germanium interface. The idea that the silicon lattice at the germanium interface expands in response to the germanium, aiding the diffusion of lithium ions, has been proposed. This idea was verified using first-principles calculations.