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Microstructure Study of Electrochemically Driven Li x Si
Author(s) -
Son SeoungBum,
Trevey James E.,
Roh Hyunchul,
Kim SungHwan,
Kim KeeBum,
Cho Jong Soo,
Moon JeongTak,
DeLuca Christopher M.,
Maute Kurt K.,
Dunn Martin L.,
Han Heung Nam,
Oh Kyu Hwan,
Lee SeHee
Publication year - 2011
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.201100360
Subject(s) - materials science , microstructure , silicon , lithium (medication) , battery (electricity) , anode , high resolution transmission electron microscopy , amorphous solid , particle (ecology) , lithium ion battery , electrode , nanotechnology , amorphous silicon , chemical engineering , composite material , crystalline silicon , transmission electron microscopy , optoelectronics , crystallography , chemistry , engineering , endocrinology , oceanography , power (physics) , quantum mechanics , medicine , physics , geology
We report the direct observation of microstructural changes of Li x Si electrode with lithium insertion. HRTEM experiments confirm that lithiated amorphous silicon forms a shell around a core made up of the unlithiated silicon and that fully lithiated silicon contains a large number of pores of which concentration increases toward the center of the particle. Chemomechanical modeling is employed in order to explain this mechanical degradation resulting from stresses in the Li x Si particles with lithium insertion. Because lithiation‐induced volume expansion and pulverization are the key mechanical effects that plague the performance and lifetime of high‐capacity Si anodes in lithium‐ion batteries, our observations and chemomechanical simulation provide important mechanistic insight for the design of advanced battery materials.