Structural evolution of Si-based anode materials during the lithiation reaction.

Si-based materials have been intensively investigated as anode materials for Li-ion batteries. However, the structural evolution of the materials during the lithiation reaction is still unrevealed. In this paper, the structural parameters and mechanical properties of Si, SiOx(0 < x < 2) and SiO2during the lithiation reaction are studied by first-principle calculation based on density functional theory. The relationship between the Li number and expansion coefficient, elastic constant, modulus, and Poisson's ratio is systematically calculated.