|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Computational Materials Discovery and Optimization: From 2D to Bulk Materials
||Lithiation Kinetics of Crystalline Silicon Nanowires Regulated by Native Oxide Layer: A Molecular Dynamics Simulation Using ReaxFF.
||Alireza Ostadhossein, Adri C.T. van Duin
|On-Site Speaker (Planned)
Practical use of silicon nanowires (Si NWs) as anodes for Li-ion batteries has been hampered by their expansion upon lithiation process. We report the mechanisms of lithiation in crystalline Si NWs covered by a native oxide layer – which is omnipresent but often ignored - using a large-scale molecular dynamic simulation via ReaxFF. Our simulations on c-Si core/SiO2 shell indicates that longitudinal expansion of lithiated core debond it from the shell. The radial expansion is limited by oxide shell due to the constraining effect of strong lithiated product. The stress calculation reveals that hydrostatic pressure is generated near the Si/SiO2 interface and at the center of Si core which is contrary to the tensile stress in NWs without oxide shell retard the lithaition. Larger NWs show smaller compressive stress and in turn higher lithiation. Thus, Lithiation kinetics is strongly affected by the native oxide layer.
||Planned: A print-only volume