%0 Conference Paper
%A Basak, Shibabrata
%A Tavabi, Amir Hossein
%A George, Chandramohan
%A Mayer, Joachim
%A Dunin-Borkowski, Rafal
%A Eichel, Rüdiger-A.
%T Thickness dependent coating breaking during battery cycling by in situ TEM
%M FZJ-2022-05276
%D 2022
%X Si has gained considerable attraction as an anode material in Li-ion batteries, in which composite electrodes that have different amounts of Si and carbon (with a theoretical capacity for Si of above ∼4000 mAhg-1 based on a Li22S5 stoichiometry) offer an enhancement in capacity when compared with pure graphite powder (∼370 mAhg−1). However, the breaking of Si particles because of strain caused by repeated lithiation (during battery charge/discharge cycles) limits exploitation of their full capacity and rate capabilities. In particular, the large volume change (>300%) of Si particles upon lithiation can result in particle pulverisation, accompanied by excessive solid electrolyte interphase (SEI) formation. The size-dependent cracking and shape-dependent lithiation behavior of Si has been reported, which provided indications about how the mechanical characteristics of Si particles evolve during battery cycling and affect their electrochemical performance. Even nanosized particles that do not easily break [1] during charge/discharge cycles owing to improved strain relaxation are still plagued by excessive electrolyte consumption associated with multiple SEI formation events, which causes rapid depletion of cyclable Li. Conformal coating of silicon (Si) anode particles is a common strategy for improving their mechanical integrity, to mitigate battery capacity fading due to particle volume expansion, which can result in particle crumbling due to lithiation induced strain and excessive solid–electrolyte interface formation. Here, we use in situ transmission electron microscopy in an open cell to show that TiO2 coatings on Si/SiO2 particles undergo thickness dependent rupture on battery cycling where thicker coatings crumble more readily than thinner (∼5 nm) coatings, which corroborates the difference in their capacities [2].
%B The Seventh Conference on Frontiers of Aberration Corrected Electron Microscopy
%C 8 May 2022 - 12 May 2022, Kasteel Vaalsbroek (Netherlands)
Y2 8 May 2022 - 12 May 2022
M2 Kasteel Vaalsbroek, Netherlands
%F PUB:(DE-HGF)6
%9 Conference Presentation
%U https://juser.fz-juelich.de/record/912049