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SUMMARY:Electrochemical Shock: Mechanical Degradation of Ion-Intercalation
  Materials
DTSTART:20140428T131500
DTEND:20140428T141500
DTSTAMP:20260924T175352Z
UID:3ff0e9edea296fb087a25c4dd8f3f49f6e351311474b33256490671c
CATEGORIES:Conferences - Seminars
DESCRIPTION:Craig Carter\, Massachusetts Institute of Technology\, Cambrid
 ge USA\n(the work presented in this talk is the result of a collaboration 
 with Dr. William Woodford and Prof. Yet-Ming Chiang)\nEnergy storage is an
  enabling technology for electrified transportation and for large-scale de
 ployment of renewable energy resources such as solar and wind. For many ap
 plications\, ion-intercalation chemistries\, most notably lithium-ion\, ar
 e attractive for high energy density and chemical reversibility. However\,
  the electrode materials used in ion-intercalation batteries undergo large
  composition changes—which correlate to high storage capacity—but also
  induce structural changes and stresses that can cause performance metrics
  such as power\, achievable storage capacity\, and life to degrade.\n“El
 ectrochemical shock”—the electrochemical cycling-induced fracture of m
 aterials—contributes to impedance growth and performance degradation in 
 ion-intercalation batteries. Using a combination of micromechanical models
  and in operando acoustic emission experiments\, the mechanisms of electro
 chemical shock are identified\, classified\, and modeled in targeted model
  systems with different composition and microstructure. Three distinct mec
 hanisms of electrochemical shock are identified\, and a fracture mechanics
  failure criterion is derived for each mechanism.\nThis fundamental unders
 tanding of electrochemical shock leads naturally to practical design crite
 ria for battery materials and microstructures that improve performance and
  energy storage efficiency. In a given material system\, crystal symmetry 
 and phase-behavior determine the active mechanisms. A surprising result is
  that electrochemical shock in commercial lithium-storage materials occurs
  by mechanisms that are insensitive to the electrochemical cycling rate. U
 sing LiCoO2\, LiMn2O4\, and LiMn1.5Ni0.5O4 as model systems\, electrochemi
 cal shock is observed during low-rate electrochemical cycling\, in agreeme
 nt with micromechanical models. Finally\, iron-doping of LiMn1.5Ni0.5O4 is
  demonstrated to qualitatively change the phase-behavior in this material\
 ; this overcomes the low cycling rate electrochemical shock mechanisms and
  enables a wider range of particle sizes and duty cycles to be used withou
 t electrochemical shock. While lithium-storage materials are used as model
  systems for experimental study\, the physical phenomena are common to oth
 er ion-intercalation systems\, including sodium- and magnesium-storage com
 pounds.\nBio: Bio
LOCATION:MXF 1 https://plan.epfl.ch/?room==MXF%201
STATUS:CONFIRMED
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