Abstract
Using first principle calculations, we uncover the underlying mechanisms explaining the brittle-to-ductile transition of LixSi electrodes in lithium ion batteries with increasing Li content. We show that plasticity initiates at x = ∼ 0.5 with the formation of a craze-like network of nanopores separated by Si-Si bonds, while subsequent failure is still brittle-like with the breaking of Si-Si bonds. Transition to ductile behavior occurs at x ≥ 1 due to the increased density of highly stretchable Li-Li bonds, which delays nanopore formation and stabilizes nanopore growth. Collapse of the nanopores during unloading of the LixSi alloys leads to significant strain recovery.
Original language | English (US) |
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Article number | 104703 |
Journal | Journal of Chemical Physics |
Volume | 143 |
Issue number | 10 |
DOIs | |
State | Published - Sep 14 2015 |
ASJC Scopus subject areas
- General Physics and Astronomy
- Physical and Theoretical Chemistry