A Computational Comparative Study of the Lithium Diffusion in Amorphous Silicon Spheres, Rods, and Circular Disks
| Autor: | Minh-Quy Le, Thanh-Lam Bui, Huu-Tu Nguyen |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Amorphous silicon
Materials science Silicon Renewable Energy Sustainability and the Environment Mechanical Engineering Energy Engineering and Power Technology chemistry.chemical_element 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Finite element method Rod 0104 chemical sciences Electronic Optical and Magnetic Materials Anode chemistry.chemical_compound chemistry Mechanics of Materials Lithium SPHERES Diffusion (business) Composite material 0210 nano-technology |
| Zdroj: | Journal of Electrochemical Energy Conversion and Storage. 18 |
| ISSN: | 2381-6910 2381-6872 |
| Popis: | We study through extensive finite element analysis the lithium diffusion in small elements of Si anodes under the forms of spheres, rods, and circular disks for Li-ion batteries. Elastoplastic properties of the amorphous silicon are assumed to be lithium concentration-dependent. Effects of the normalized flux of Li-ions on the lithium concentrations, stresses, and total equivalent plastic strains are considered. Effects of the disk's thickness are also included. At a given normalized flux, the heterogeneity of the lithiation, stresses, and plastic deformation increases in the order: disk, sphere, and rod. The thinner disk the better performance is. Below a critical value of the normalized flux of Li-ions, silicon spheres and disks exhibit linear elasticity and homogeneous distribution of Li-ions, whereas silicon rods undergo always plastic deformation after lithiation. When the radii of these three structures are smaller than several micrometers and the normalized flux is taken as 95% of their critical value, the charge time falls in the range from minutes to several hours. Our findings will help to optimize the charge and geometrical parameters for silicon anodes. |
| Databáze: | OpenAIRE |
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