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Title: Lithium concentration dependent structure and mechanics of amorphous silicon

Abstract

A better understanding of lithium-silicon alloying mechanisms and associated mechanical behavior is essential for the design of Si-based electrodes for Li-ion batteries. Unfortunately, the relationship between the dynamic mechanical response and microstructure evolution during lithiation and delithiation has not been well understood. We use molecular dynamic simulations to investigate lithiated amorphous silicon with a focus to the evolution of its microstructure, phase composition, and stress generation. The results show that the formation of Li{sub x}Si alloy phase is via different mechanisms, depending on Li concentration. In these alloy phases, the increase in Li concentration results in reduction of modulus of elasticity and fracture strength but increase in ductility in tension. For a Li{sub x}Si system with uniform Li distribution, volume change induced stress is well below the fracture strength in tension.

Authors:
; ; ; ;  [1];  [2]
  1. School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology (QUT), Brisbane QLD 4001 (Australia)
  2. Centre for Clean Environment and Energy, Environmental Futures Research Institute and Griffith School of Environment, Gold Coast Campus, Griffith University, QLD 4222 (Australia)
Publication Date:
OSTI Identifier:
22596671
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 119; Journal Issue: 24; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ABUNDANCE; AMORPHOUS STATE; COMPUTERIZED SIMULATION; DUCTILITY; ELASTICITY; ELECTRODES; FRACTURE PROPERTIES; FRACTURES; LITHIUM; LITHIUM ALLOYS; LITHIUM ION BATTERIES; LITHIUM IONS; MECHANICS; MICROSTRUCTURE; SILICON; SILICON ALLOYS; STRESSES

Citation Formats

Sitinamaluwa, H. S., Wang, M. C., Will, G., Senadeera, W., Yan, C., E-mail: c2.yan@qut.edu.au, and Zhang, S. Lithium concentration dependent structure and mechanics of amorphous silicon. United States: N. p., 2016. Web. doi:10.1063/1.4954683.
Sitinamaluwa, H. S., Wang, M. C., Will, G., Senadeera, W., Yan, C., E-mail: c2.yan@qut.edu.au, & Zhang, S. Lithium concentration dependent structure and mechanics of amorphous silicon. United States. doi:10.1063/1.4954683.
Sitinamaluwa, H. S., Wang, M. C., Will, G., Senadeera, W., Yan, C., E-mail: c2.yan@qut.edu.au, and Zhang, S. 2016. "Lithium concentration dependent structure and mechanics of amorphous silicon". United States. doi:10.1063/1.4954683.
@article{osti_22596671,
title = {Lithium concentration dependent structure and mechanics of amorphous silicon},
author = {Sitinamaluwa, H. S. and Wang, M. C. and Will, G. and Senadeera, W. and Yan, C., E-mail: c2.yan@qut.edu.au and Zhang, S.},
abstractNote = {A better understanding of lithium-silicon alloying mechanisms and associated mechanical behavior is essential for the design of Si-based electrodes for Li-ion batteries. Unfortunately, the relationship between the dynamic mechanical response and microstructure evolution during lithiation and delithiation has not been well understood. We use molecular dynamic simulations to investigate lithiated amorphous silicon with a focus to the evolution of its microstructure, phase composition, and stress generation. The results show that the formation of Li{sub x}Si alloy phase is via different mechanisms, depending on Li concentration. In these alloy phases, the increase in Li concentration results in reduction of modulus of elasticity and fracture strength but increase in ductility in tension. For a Li{sub x}Si system with uniform Li distribution, volume change induced stress is well below the fracture strength in tension.},
doi = {10.1063/1.4954683},
journal = {Journal of Applied Physics},
number = 24,
volume = 119,
place = {United States},
year = 2016,
month = 6
}
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