Orientation-Dependent Interfacial Mobility Governs the Anisotropic Swelling in Lithiated Silicon Nanowires
- 22 March 2012
- journal article
- Published by American Chemical Society (ACS) in Nano Letters
- Vol. 12 (4), 1953-1958
- https://doi.org/10.1021/nl204437t
Abstract
Recent independent experiments demonstrated that the lithiation-induced volume expansion in silicon nanowires, nanopillars, and microslabs is highly anisotropic, with predominant expansion along the ⟨110⟩ direction but negligibly small expansion along the ⟨111⟩ direction. The origin of such anisotropic behavior remains elusive. Here, we develop a chemomechanical model to study the phase evolution and morphological changes in lithiated silicon nanowires. The model couples the diffusive reaction of lithium with the lithiation-induced elasto-plastic deformation. We show that the apparent anisotropic swelling is critically controlled by the orientation-dependent mobility of the core–shell interface, i.e., the lithiation reaction rate at the atomically sharp phase boundary between the crystalline core and the amorphous shell. Our results also underscore the importance of structural relaxation by plastic flow behind the moving phase boundary, which is essential to quantitative prediction of the experimentally observed morphologies of lithiated silicon nanowires. The study sheds light on the lithiation-mediated failure in nanowire-based electrodes, and the modeling framework provides a basis for simulating the morphological evolution, stress generation, and fracture in high-capacity electrodes for the next-generation lithium-ion batteries.Keywords
This publication has 42 references indexed in Scilit:
- Getting ThereScience, 2011
- Ultrafast Electrochemical Lithiation of Individual Si Nanowire AnodesNano Letters, 2011
- A review of advanced and practical lithium battery materialsJournal of Materials Chemistry, 2011
- A review of the electrochemical performance of alloy anodes for lithium-ion batteriesJournal of Power Sources, 2011
- Crystalline-Amorphous Core−Shell Silicon Nanowires for High Capacity and High Current Battery ElectrodesNano Letters, 2009
- High-performance lithium battery anodes using silicon nanowiresNature Nanotechnology, 2007
- Nanostructured materials for advanced energy conversion and storage devicesNature Materials, 2005
- Structural Changes in Silicon Anodes during Lithium Insertion/ExtractionElectrochemical and Solid-State Letters, 2004
- Issues and challenges facing rechargeable lithium batteriesNature, 2001
- Colossal Reversible Volume Changes in Lithium AlloysElectrochemical and Solid-State Letters, 2001