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In situ and Operando Tracking of Microstructure and Volume Evolution of Silicon Electrodes by using Synchrotron X‐ray Imaging
Author(s) -
Dong Kang,
Markötter Henning,
Sun Fu,
Hilger André,
Kardjilov Nikolay,
Banhart John,
Manke Ingo
Publication year - 2019
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201801969
Subject(s) - synchrotron , silicon , materials science , microstructure , electrolyte , battery (electricity) , electrode , shrinkage , particle (ecology) , lithium (medication) , synchrotron radiation , chemical engineering , nanotechnology , chemical physics , composite material , optoelectronics , chemistry , optics , medicine , power (physics) , physics , oceanography , engineering , endocrinology , geology , quantum mechanics
Abstract The internal microstructure of a silicon electrode in a lithium ion battery was visualized by operando synchrotron X‐ray radioscopy during battery cycling. The silicon particles were found to change their sizes upon lithiation and delithiation and the changes could be quantified. It was found that volume change of a particle is related to its initial size and is also largely determined by the changing surrounding electron‐conductive network and internal interface chemical environment (e.g., electrolyte migration, solid–electrolyte interphase propagation) within fractured particles. Moreover, an expansion prolongation phenomenon was discovered whereby some particles continue expanding even after switching the battery current direction and shrinkage would be expected, which is explained by assuming different expansion characteristics of particle cores and outer regions. The study provides new basic insights into processes inside Si particles during lithiation and delithiation and also demonstrates the unique possibilities of operando synchrotron X‐ray imaging for studying degradation mechanisms in battery materials.