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Title: High damage tolerance of electrochemically lithiated silicon

Mechanical degradation and resultant capacity fade in high-capacity electrode materials critically hinder their use in high-performance rechargeable batteries. Despite tremendous efforts devoted to the study of the electro–chemo–mechanical behaviours of high-capacity electrode materials, their fracture properties and mechanisms remain largely unknown. In this paper, we report a nanomechanical study on the damage tolerance of electrochemically lithiated silicon. Our in situ transmission electron microscopy experiments reveal a striking contrast of brittle fracture in pristine silicon versus ductile tensile deformation in fully lithiated silicon. Quantitative fracture toughness measurements by nanoindentation show a rapid brittle-to-ductile transition of fracture as the lithium-to-silicon molar ratio is increased to above 1.5. Molecular dynamics simulations elucidate the mechanistic underpinnings of the brittle-to-ductile transition governed by atomic bonding and lithiation-induced toughening. Finally, our results reveal the high damage tolerance in amorphous lithium-rich silicon alloys and have important implications for the development of durable rechargeable batteries.
Authors:
 [1] ;  [1] ;  [2] ;  [3] ;  [1] ;  [1] ;  [4] ;  [3] ;  [2] ;  [1] ;  [1]
  1. Georgia Inst. of Technology, Atlanta, GA (United States). Woodruff School of Mechanical Engineering
  2. Univ. of Pittsburgh, PA (United States). Dept. of Mechanical Engineering and Materials Science
  3. Univ. of Illinois, Urbana, IL (United States). Dept. of Aerospace Engineering
  4. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Center for Integrated Nanotechnologies
Publication Date:
OSTI Identifier:
1261096
Grant/Contract Number:
AC04-94AL85000; NSF-CMMI-1300458; NSF-CMMI-1300805; NSF-CMMI-1100205; NSF-DMR-1410936; NSF-CMMI-08010934
Type:
Accepted Manuscript
Journal Name:
Nature Communications
Additional Journal Information:
Journal Volume: 6; Journal ID: ISSN 2041-1723
Publisher:
Nature Publishing Group
Research Org:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
25 ENERGY STORAGE; 36 MATERIALS SCIENCE chemical sciences; materials science; nanotechnology