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Capacity Fade Mechanism of Li 4 Ti 5 O 12 Nanosheet Anode
Author(s) -
Chiu HsienChieh,
Lu Xia,
Zhou Jigang,
Gu Lin,
Reid Joel,
Gauvin Raynald,
Zaghib Karim,
Demopoulos George P.
Publication year - 2017
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.201601825
Subject(s) - materials science , nanosheet , anode , electrolyte , polarization (electrochemistry) , nucleation , ion , titanate , lithium titanate , chemical engineering , intercalation (chemistry) , electrode , lithium (medication) , nanotechnology , nanostructure , chemical physics , inorganic chemistry , lithium ion battery , composite material , battery (electricity) , chemistry , medicine , ceramic , power (physics) , organic chemistry , quantum mechanics , endocrinology , engineering , physics
Zero‐strain and long‐term stability of nanoscale lithium titanate (LTO) anode materials make possible the fabrication of exceptionally stable lithium ion batteries. But one issue must be considered that of nanostructure‐induced relaxation in 2D LTO nanosheets which profoundly modifies their Li storage properties and structural stability. Excessively intercalated Li ions at both 8 a and 16 c sites trigger nucleation of the relaxed LTO structure in the near‐surface region, which impedes Li‐ion diffusion and causes the increasing polarization of LTO nanosheet electrodes. Nuclei of relaxed LTO then undergo isotropic growth along the 3D Li‐ion pathways in LTO to completely convert near‐surface regions into relaxed LTO. With increasing population of trapped Li ions, the enhanced conductivity due to Ti 4+ /Ti 3+ reduction gradually eliminates the raised polarization. In the meantime, spontaneous electrolyte/LTO reduction to form the solid electrolyte interphase starts playing a major role in capacity loss once the transformation of near‐surface region into relaxed LTO becomes saturated. Elucidation of these fundamental intercalation‐induced surface structure transformations contribute greatly into the design of highly performing 2D nanoscaled LTO and other electrode materials.