Lithium concentration dependent structure and mechanics of amorphous silicon

Journal Article · Tue Jun 28 00:00:00 EDT 2016 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4954683· OSTI ID:22596671

Sitinamaluwa, H. S.; Wang, M. C.; Will, G.; Senadeera, W.; Zhang, S. ^[1]

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1. Centre for Clean Environment and Energy, Environmental Futures Research Institute and Griffith School of Environment, Gold Coast Campus, Griffith University, QLD 4222 (Australia)

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.

• OSTI ID: 22596671
• Journal Information: Journal of Applied Physics, Vol. 119, Issue 24; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

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