Post on 30-Aug-2020
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Song Xu, Ph.D.
Sr. Application Scientist
Keysight Technologies
In-situ Study of Lithium Battery with Electrochemistry/ AFM
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Page Why are we interested in battery research?
The Original Question of all: Why
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Lithium Battery
Page SEM Observation of Solid-Electrolyte Interphase
Elsevier , “Comparative study of the solid electrolyte interphase on graphite in full Li-ion battery cells using X-ray photoelectron
spectroscopy, secondary ion mass spectrometry, and electron microscopy”
Jung Tae Lee a, Naoki Nitta a, James Benson a, Alexandre Magasinski a,
Thomas F. Fuller b, Gleb Yushin a,*
Lithium Battery
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AFM / STM In Liquid Imaging is used to observe the formation of SEI
in-situ and in real time
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Changing potential while scanning
Fixed potential
Basics of Electrochemistry AFM/STM: the in-situ and the resolution
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EC Bulk Cu Crystal Deposition
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Reference electrode
Electrolyte
Combning AFM/STM with the potentialstate to form EC-AFM/STM
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Basics of Electrochemistry AFM/STM: the sample cell
reference electrode
(no connection with
other electrodes)
counter electrode
(no connection with
other electrodes)
working electrode (in contact with Au)
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Basics of Electrochemistry AFM/STM: Design of glove box
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Basics of Electrochemistry AFM/STM: Environmental control with professional glove box
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DALHOUSIE
University
luc@dahn.phys.dal.ca
www.physics.dal.ca/~dahn
The problems of AFM inside a professional glove box: noise and
vibration isolation
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Solution to the problem: miniature vibration isolation
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Solution to the problem: miniature vibration isolation
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Solution to the problem: miniature vibration isolation
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reference electrode
(no connection with
other electrodes)
counter electrode
(no connection with
other electrodes)
working electrode (in contact with Au)
The problems of AFM inside a professional glove box: Electrical
Chemistry Cell
Problems
•Small parts
•Leak
•evaporation
•Corrosion
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Electrodes
Reference electrode: Mostly Ag, Cu ok for Cu deposition
experiment
Counter electrode: Mostly Pt, Cu ok for Cu deposition experiment.
The long loop is for the large current in the big
AFM cell. STM counter electrode doesn’t need the
loop.
The problems of AFM inside a professional glove box: Small parts of
Electrical Chemistry Cell
Page DALHOUSIE
University
luc@dahn.phys.dal.ca
www.physics.dal.ca/~dahn
Electrode Lithium
Electrode
The problems of AFM inside a professional glove box: Small parts of
Electrical Chemistry Cell
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Customizable in
Footer 19
The problems of AFM inside a professional glove box: and handling
and the corrosion
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Solution to the problems of AFM inside a professional glove box: EC
cell made for easy to handle
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Solution to the problems of AFM inside a professional glove box: EC
cell made for easy to handle
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In-situ observation of SEI on HOPG electrode surface during charging
circle of a Li ion battery cell—the first circle
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In-situ observation of SEI on HOPG electrode surface during charging
circle of a Li ion battery cell—the first circle
AFM images of HOPG
surface scanned at a
synchronous discharge
voltage range of
a) 3.0 e 2.95 V;
b) b) 1.7 e 1.65 V;
c) c) 1.0 e 0.95 V;
d) d) 0.5 e 0.45 V;
e) e) 0.1 e 0.05 V.
Scan area 25 mm2.
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In-situ observation of bottom SEI on HOPG electrode surface during
charging circle of a Li ion battery cell—the first circle
AFM images of bottom SEI layer:
a) pristine HOPG;
b) b) discharge to 1.7 V;
c) c) discharge to 0.5 V;
d) d) discharge to 0.02 V.
Scan area 25 mm2.
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In-situ observation of SEI on HOPG electrode surface during charging
circle of a Li ion battery cell—the first circle
Schematic of SEI evolutions during the first discharge process.
a) The solvent decomposition product (purple dots) deposits at the surface of the graphite;
b) the solvated lithium ions (gray dots) pass through the particle layer and intercalated into the graphite layer (black lines);
c) solvent decomposition products accumulate at the surface when the
lithium intercalation takes places;
d) the displacement of the graphite layer caused by the lithium intercalation pushes the top particle layer off the HOPG surface;
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In-situ observation of SEI on HOPG electrode surface during charging
circle of a Li ion battery cell—the delamination of the first SEI layer
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In-situ observation of SEI on HOPG electrode surface during charging
circle of a Li ion battery cell- the bottom SEI
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In-situ observation of SEI on HOPG electrode surface during charging
circle of a Li ion battery cell- the bottom SEI
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In-situ observation of SEI on HOPG electrode surface during charging
circle of a Li ion battery cell- the bottom SEI is a soft layer
Center framed area scanned at higher force (10nN)
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On going work
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On-going work: mechanical properties measurement of mechanical
properties of SEI of Li battery cell
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Future work: Better solution to the problems of AFM inside a
professional glove box: EC cell made for easy to handle and resist to
corrosion
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Future work: EC AFM cell for Litihium Cell with heating and cooling
option
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Future work: EC AFM cell for Litihium Cell with oxygen feed to a porous
sample electrode
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Some small inventions: Sample transfer holder from glove box to SEM /
XPS
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Conclusion:
We observed Litihum battery SEI formation in-situ in real time
future:
Mechanical property measurement of SEI on HOPG electrode surface
during charging circle of a Li ion battery cell
Temperature based study: heating and cooling