title: In situ X-ray diffraction studies of (de)lithiation mechanism in silicon nanowire anodes.
abstract: Silicon is a promising anode material for Li-ion batteries due to its high theoretical specific capacity. From previous work, silicon nanowires (SiNWs) are known to undergo amorphorization during lithiation, and no crystalline Li-Si product has been observed. In this work, we use an X-ray transparent battery cell to perform in situ synchrotron X-ray diffraction on SiNWs in real time during electrochemical cycling. At deep lithiation voltages the known metastable Li(15)Si(4) phase forms, and we show that avoiding the formation of this phase, by modifying the SiNW growth temperature, improves the cycling performance of SiNW anodes. Our results provide insight on the (de)lithiation mechanism and a correlation between phase evolution and electrochemical performance for SiNW anodes.
authors.affiliation: Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: Sumohan
authors.initials: S
authors.lastname: Misra
authors.forename: Nian
authors.initials: N
authors.lastname: Liu
authors.forename: Johanna
authors.initials: J
authors.lastname: Nelson
authors.forename: Seung Sae
authors.initials: SS
authors.lastname: Hong
authors.forename: Yi
authors.initials: Y
authors.lastname: Cui
authors.forename: Michael F
authors.initials: MF
authors.lastname: Toney
mesh_terms: D004566:Electrodes; D008094:Lithium / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D036103:Nanotechnology / Q000379:methods*; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D012825:Silicon / Q000737:chemistry*; D013499:Surface Properties; D014961:X-Ray Diffraction
chemical_list: D046911:Macromolecular Substances; D008094:Lithium; D012825:Silicon