title: Brittle-to-ductile transition of lithiated silicon electrodes: Crazing to stable nanopore growth.
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.
authors.affiliation: Department of Aerospace Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: Haoran
authors.initials: H
authors.lastname: Wang
authors.affiliation: Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
authors.forename: Xueju
authors.initials: X
authors.lastname: Wang
authors.affiliation: Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
authors.forename: Shuman
authors.initials: S
authors.lastname: Xia
authors.affiliation: Department of Aerospace Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: Huck Beng
authors.initials: HB
authors.lastname: Chew