Aging mechanisms in Lithium ion batteries revealed by GD ...
Transcript of Aging mechanisms in Lithium ion batteries revealed by GD ...
18. GDS Anwendertreffen
26.09.2019, Freiberg
Karsten Richter, Thomas Waldmann, Michaela Memm, Michael Kasper,
Peter Axmann, Margret Wohlfahrt-Mehrens
Zentrum für Sonnenenergie- und Wasserstoff-Forschung
Baden-Württemberg (ZSW)
Aging mechanisms in Lithium ion batteries revealed
by GD-OES depth profiling
- 2 -
Working principal and aging mechanism
Mechanism related to
Li deposition
SEI
Li
Li
Li
Li
Li
Li
Li Li Li
Anode
CathodeAmbient charging
conditions
Low currents /
room temp.
SEI
Li
LiLi
Li
Li
Li
Li
Li
Li
Challenging
charging conditions
high currents /
low temp.
[1] T. Waldmann, B.-I. Hogg, M. Wohlfahrt-Mehrens, J. Power Sources 2018, 384, 107–124.
- 3 -
Li metal deposition – Spatially resolved
0 2 4 6 80
5
10
15
20
25
30
35
40
C
P
Li
depth / µm
Li, O
, P
/ w
t.-%
O
0
20
40
60
80
100
C / w
t.-%
0 2 4 6 80
5
10
15
20
25
30
35
40
C
P
Li
O
depth / µm
Li, O
, P
/ w
t.-%
0
20
40
60
80
100
C / w
t.-%
- dominant
dendritic structure
Li metal
deposition
- inhomogeneous
and small dendritic
structures visible
[2] T. Waldmann, J. B. Quinn, K. Richter, M. Kasper, A. Tost, A. Klein, M. Wohlfahrt-Mehrens, J. Electrochem. Soc. 2017, 164, A3154–A3162.
SEM
CT
- 4 -
Li metal deposition – Effect of resting time
0 2 4 6 80
5
10
15
20
25
30
35
40
P
Li
O
depth / µm
Li, O
, P
/ w
t-%
C
0
20
40
60
80
100
C / w
t.-%
0 2 4 6 80
5
10
15
20
25
30
35
40
C
P
Li
depth / µm
Li, O
, P
/ w
t.-%
O
0
20
40
60
80
100
C / w
t.-%
8 h
GD
-OE
SS
EM
- after cell operation:
dominant Li metal
deposition and high
surface concentration of Li
- after resting broad and
flat Li distribution
GD-OES reveals
reintercalation of Li
No dendritic structure
visible
[2] T. Waldmann, J. B. Quinn, K. Richter, M. Kasper, A. Tost, A. Klein, M. Wohlfahrt-Mehrens, J. Electrochem. Soc. 2017, 164, A3154–A3162.
rest
- 5 -
Aging mechanism – Effect of operating temperature
0 2 4 6 80
5
10
15
20
25
30
35
40
PLi
O
depth / µm
Li, O
, P
/ w
t-%
C
0
20
40
60
80
100
C / w
t.-%
0 2 4 6 80
5
10
15
20
25
30
35
40
C
P
Li
depth / µm
Li, O
, P
/ w
t.-%
O
0
20
40
60
80
100
C / w
t.-%
0 2 4 6 80
5
10
15
20
25
30
35
40
P
Li O
C
depth / µm
Li, O
, P
/ w
t-%
0
20
40
60
80
100
C /
wt.-%
Fresh cell: initial SEICycling at 0 °C: Li metal
covers anode Surface
Cycling at 45 °C: Un-
ceasing film formation (e.g.
Li2O, Li2CO3)
[2] T. Waldmann, J. B. Quinn, K. Richter, M. Kasper, A. Tost, A. Klein, M. Wohlfahrt-Mehrens, J. Electrochem. Soc. 2017, 164, A3154–A3162.
Graphite, LiC6: 372 mAh g-1
Silicon, Li15Si4: 3579 mAh g-1
- 6 -
Increasing demand for energy
lithiation
delit
hia
tion
binder
conductive additive
passiv
atio
n
High volume expansion
- Particle cracking
- Contact loss
- Ongoing film formation and
Li+-Ion consumption
- Formation of passivation
layer and intrinsic
mechanical instability
(mixing, volume change)
- Anisotropic de-/lithiation
[3] M. N. Obrovac, L. Christensen, D. B. Le, J. R. Dahn, J. Electrochem. Soc. 2007, 154, A849. [4] M. N. Obrovac, V. L. Chevrier, Chem. Rev. 2014, 114, 11444–11502.
[5] P. Limthongkul, Y.-I. Jang, N. J. Dudney, Y.-M. Chiang, Acta Mater. 2003, 51, 1103–1113. [6] N. Delpuech, N. Dupre, P. Moreau, J.-S. Bridel, J. Gaubicher, B. Lestriez, D. Guyomard, ChemSusChem 2016, 9, 841–84
- 7 -
Si in LIB anodes – GD-OES approach
0 5 10 15 20 25 30 350
5
10
15
20
25
30
35 GD-OES
EDX
Quantified S
i (w
t.-%
)
Si in reference samples (wt.-%)0 2 4 6 8 10
0
10
20
30
40
50
60
70
80
90
100
(16.5 ± 2.5) wt.-%
(20.5 ± 1.9) wt.-%
(1.1 ± 0.1) wt.-%
(61.0 ± 0.9) wt.-%
(65.9 ± 1.5) wt.-%
Si (w
t.-%
)
depth (µm)
(99.7 ± 1.1) wt.-%
0 100 200 300 4000.0
0.1
0.2
0.3
0.4
Inte
nsity x
10
00
Si (a
.u.)
sputtering time (s)
Initial sputtering
1st interruption
2nd interruption
mean bulk intensity
0 2 4 6 80
5
10
15
20
25
P
Si
C
O
Li, O
, P
, S
i (w
t.-%
)
depth (µm)
Li20
30
40
50
60
70
80
90
100C
(w
t.-%
)
- covering 0-100 wt.-%
Si to analyse graphite
and Si dominant
composite electrodes
- unexpected Si
distribution observed
[7] K. Richter, T. Waldmann, M. Memm, M. Kasper, M. Wohlfahrt-Mehrens, J. Electrochem. Soc. 2018, 165, A3602–A3604
[8] K. Richter, T. Waldmann, M. Kasper, C. Pfeifer, M. Memm, P. Axmann, M. Wohlfahrt-Mehrens, J. Phys. Chem. C 2019, 123, 18795–18803
- 8 -
Si related aging mechanism – revealed by GD-EOS
0 2 4 6 80
5
10
15
20
25
P
Si
C
O
Li, O
, P
, S
i (w
t.-%
)
depth (µm)
Li20
30
40
50
60
70
80
90
100
C (
wt.
-%)
0 2 4 6 80
5
10
15
20
25
Li, O
, P
, S
i (w
t.-%
)
depth (µm)
Si
P
20
30
40
50
60
70
80
90
100C
(w
t.-%
)
O
C
Li
3x 60s dip washed
with DMC
- Si detectable in DMC with ICP-OES
5 SiO + 6 Li Li2O + Li4SiO4 + 4 Si
5 SiO2 + 4 Li 2 Li2Si2O5 + Si
Side reaction of active material
with electrolyte, consumes Li.
Additional film formation and
dissolution.
[7] K. Richter, T. Waldmann, M. Memm, M. Kasper, M. Wohlfahrt-Mehrens, J. Electrochem. Soc. 2018, 165, A3602–A3604
[8] K. Richter, T. Waldmann, M. Kasper, C. Pfeifer, M. Memm, P. Axmann, M. Wohlfahrt-Mehrens, J. Phys. Chem. C 2019, 123, 18795–18803
- 9 -
Si related aging mechanism – revealed by GD-EOS
0.0 0.5 1.0 1.5 2.00
5
10
15
20
25
30
35
40
Si / w
t.-%
depth / µm
Formation
50 Cy C/3 RT
50 Cy C/3 45 °C
40 Cy C/3 0 °C
0 2 4 6 8 100
5
10
15
20
25
30
35
40
Si / w
t.-%
depth / µm
Formation
50 Cy C/3 RT
50 Cy C/3 45 °C
40 Cy C/3 0 °C
0 2 4 6 8 100
5
10
15
20
25
30
35
Si / w
t.-%
depth / µm
Formation
50 Cy C/3 RT
50 Cy C/3 RT MdCh
25 Cy MdCh 25 Cy C/3 RT
0.0 0.5 1.0 1.5 2.00
5
10
15
20
25
30
35S
i / w
t.-%
depth / µm
Formation
50 Cy C/3 RT
50 Cy C/3 RT MdCh
25 Cy MdCh 25 Cy C/3 RT
- Si distribution depends on physical
and electrochemical operation
conditions
- 45 °C enhances film formation,
containing Si-rich species
- 0 °C shifts the Si distribution to
deeper levels of the electrode
- lower cut off potential increases Si
species on surface
Enhanced side reactions during
discharge
- 10 -
Conclusions
0 2 4 6 80
5
10
15
20
25
30
35
40
C
P
Li
depth / µm
Li, O
, P
/ w
t.-%
O
0
20
40
60
80
100
C /
wt.-%
- GDOES provides spatially resolved elemental
distribution
Covering the plating behaviour over the jelly
roll
- GDOES provides information about the aging
mechanism regarding cell operation conditions
Differentiation between, e.g. Li metal
deposition or electrolyte decomposition
- GDOES can be calibrated to novel battery
materials revealing material specific aging
mechanism
Film formation and dissolution on Si/C
composite materials
0 2 4 6 80
5
10
15
20
25
30
35
40
PLi
O
depth / µm
Li, O
, P
/ w
t-%
C
0
20
40
60
80
100
C / w
t.-%
0 2 4 6 80
5
10
15
20
25
30
35
40
C
P
Li
depth / µm
Li, O
, P
/ w
t.-%
O
0
20
40
60
80
100
C /
wt.-%
0 5 10 15 20 25 30 350
5
10
15
20
25
30
35 GD-OES
EDX
Quantified S
i (w
t.-%
)
Si in reference samples (wt.-%)
0 2 4 6 80
5
10
15
20
25
P
Si
C
O
Li, O
, P
, S
i (w
t.-%
)
depth (µm)
Li20
30
40
50
60
70
80
90
100
C (
wt.
-%)
0 2 4 6 80
5
10
15
20
25
Li, O
, P
, S
i (w
t.-%
)
depth (µm)
Si
P
20
30
40
50
60
70
80
90
100
C (
wt.-%
)
O
C
Li
electrode
washing
- 11 -
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Funding:
MAT4BAT – EU (n° 608931)
LIB.DE – BMWi (n° 03ET6081A)
ZSW:
Niloofar Ghanbari (now Bosch)
Thomas Waldmann
Michaela Memm
Michael Kasper
Peter Axmann
Margret Wohlfahrt-Mehrens
Spectruma:
Rüdiger Meihsner
Tatjana Leibßle
Otto Paljok
Tahir Serbet
Michael Analytis