2 research outputs found
Direct Observation of Inhomogeneous Solid Electrolyte Interphase on MnO Anode with Atomic Force Microscopy and Spectroscopy
Solid electrolyte interphase (SEI) is an in situ formed
thin coating
on lithium ion battery (LIB) electrodes. The mechanical property of
SEI largely defines the cycling performance and the safety of LIBs
but has been rarely investigated. Here, we report quantitatively the
Young’s modulus of SEI films on MnO anodes. The inhomogeneity
of SEI film in morphology, structure, and mechanical properties provides
new insights to the evolution of SEI on electrodes. Furthermore, the
quantitative methodology established in this study opens a new approach
to direct investigation of SEI properties in various electrode materials
systems
Influences of Additives on the Formation of a Solid Electrolyte Interphase on MnO Electrode Studied by Atomic Force Microscopy and Force Spectroscopy
The solid electrolyte interphase
(SEI) that forms on electrodes
largely defines the performances of lithium ion batteries (LIBs),
such as cycling performance, shelf life, and safety. Additives in
the electrolyte can modify the properties of the SEI and thus efficiently
improve the performances of LIBs. However, the effects of additives
on the mechanical properties, structure, and stability of the SEI
have rarely been studied directly. In this paper, we report the influence
of vinylene carbonate (VC) and lithium bisÂ(oxalate)Âborate (LiBOB)
additives on the mechanical properties of SEI films formed on MnO
electrodes using atomic force microscopy (AFM) and force spectroscopy.
The results show that the SEI formed from VC additive is thick and
soft and partially decomposes upon charging. LiBOB forms thin, stiff,
and electrochemically stable SEI films, but the stiff SEI may not
be favorable for adapting the volume change of the electrodes. The
VC and LiBOB mixed additive combines the advantages of the two components
and produces stable SEI with moderate thickness and stiffness. This
work also demonstrates that the AFM–force spectroscopy method
is effective in investigating the structure and mechanical properties
of SEI films