1. New diagnosis method for LIB health
conditions using EIS
Faculty of Science and Engineering
Waseda University
Tetsuya Osaka
March 10th, 2015
"Science Symposium Ludwigshafen“
BASF Science Symposium 2015
1
Contents
• Introduction
• Design of Equivalent Circuit for Electrochemical
Impedance Spectroscopy on LIB
• Dependence of EIS on Temperature
• EIS for Degradation Analysis of LIBs
• Square Current/Potential-EIS
• Summary
2

2. Introduction
What is
Electrochemical Impedance Spectroscopy (EIS)?
Input signal
-0.005
0
0.005
0.005 0.01 0.015
-Z"/Ω
Z’ / Ω
Frequency response
Measure Data processing
EIS can
 analyze electrochemical devises without destruction of the
devises, because of small-amplitude sinusoidal input.
 divide complicated process of electrochemical reaction into
elemental processes, because of their characteristic frequency.
EIS method can be powerful for evaluation of Lithium-ion battery (LIB)
3
The Electrochemical Society Interface
PENNINGTON CORNER
I
Electrochemistry plays a
ATurningPointfor ECS
Journal of The Electrochemical Society
th
Tetsuya Osaka
ECS President
Recycling plant of battery
Maintenance‐free
Analysis without destruction
Substation
Smart grid
Substation
Substation
Possibilities of Innovation from Battery Systems
Plug‐in hybrid vehicles (PHEVs)
Battery electric vehicles (BEVs)
Fuel cell electric vehicles (FCEVs)
Home energy management system
(HEMS)
Factory energy management system
(FEMS)
Solar power
Wind power
Air plane
PENNINGTON CORNER
I
ATurningPointfor ECS
Journal of The Electrochemical Society
4

3. 5
Recurrence Movement of LIB Technology to Japan
Example of LIB accidents
【電気自動車】 浙
江
省杭州市の武林路で2011年4月11日午後３時（日本時間４時）ごろ、電動タクシー
が発火・炎上した。乗客はなく、けが人はいなかった。（新華社、鞠煥宗撮影）
2011.4.11,早朝 2011.4.11,早朝
2011.4.11,16時 2011.7.10,早朝
2011.11.26
Fig1 ﾌﾗﾝｽでの事故 Fig.2 ブラジルでの発火事故
iPhoneが発熱し，煙と火花が出るという怖い体験をしたユーザーたちがいる．ブラジルで1台，オーストラリ
アの飛行機内で1台のiPhoneから火が出た．
先に報告されたのはオーストラリアでの発火だ．11月25日，リズモア発シドニー行きのRegional Express航
空の機内でのことだ．RegionalExpress社の公式声明によると，着陸後，ある乗客の携帯電話が「かなりの
寮の濃い煙を出し，やがて赤く光った」．客室乗務員が消火し，けが人は出なかったという．
機種は公表されておらず，上に掲載した写真では，「iPhone 4」か「iPhone 4S」かは判断できない．
ブラジルの発火は11月22日で，オーストラリアの発火より先に起きていたが，報告されたのは最近のこと
だ．アイラ・モタさんが，フランスで購入した８GBのiPhone 4を充電しようとして，コンセントにつないで就寝
した．夜中に目を覚ますとiPhoneから火花と煙が出ていたという．
6
EVs mount LIBs made in China began to spread after Shanghai EXPO.
Several years passed from the EXPO, accidents of the EVs have increased.
Because safety on long cycles are not enough. Therefore Japanese
technology has been attracted again, resulting in recurrence movement of LIB
technology to Japan

4. Super dry room and
Production line of lithium secondary batteries (< 1 Ah)
【Super dry room】
Floor area：ca. 14.85m3
Cleanness (Minimum)：100 (JIS B9920クラス5)
Dew point of air supply：‐95℃
Dew point in the room：‐70℃
connected directly with 2 glove boxes
(Dew point <‐95℃, O2 < 2ppm)
【Laminated LIB fabrication】
a) Mixier, b) Electrode coater
c) Roll press, d) Ultrasonic welder
e) Heat sealer,
f) Vacuum sealer with electrolyte supply
Leading LIB fabrication process in academic field
A number of evaluation equipment for LIBs
Charge‐discharge
test equipment
Glove box filled with Ar（Dew point：‐110℃）
Electrochemical
measurement system
Second dry room was built
on the basis of the experience by the first one.
Floor area：8.75 m2，
Dew point in the room：‐60℃
Dew point of air supply：‐95℃（0.04 ppm）
Dew point in the room：‐70℃
7
First dry room
Floor area：14.85 m2
First introduction of a super dry room
among universities in Japan (1999)
Construction of leading-edge dry room
on the basis of the know-how by first super dry room (2010)
 Deliver CUTTING EDGE MATERIALS and TECHNOLOGIES
Facility for production of medium sized LIB: Laminate type (~5Ah)
Final completion in March, 2014
Super dry room and
Production line of lithium secondary batteries
8
【Dry room】
Floor area：ca. 62.71m3
Cleanness (max.)：10000
Dew point of supply air ：‐80℃
Dew point in the room：‐50℃
【Apparatuses for Laminated LIB】
・In dry room
Clicking machine，Roll press machine, Welder，
Film mold machine，Heat sealer,
Vacuum sealer with electrolyte injector，etc.
・Clean bench
Mixer, Coater

5. Super dry room and
Production line of lithium secondary batteries (~10 Ah)
Ultrasonic WelderCutting frame
Dry room: 60 m2 + Coating space: 6 m2
Production line of lithium secondary batteries (10 Ah class)
Full automatic
lamination system
Heat sealer Electrolyte injector and
vacuum sealer
LIB production ability of our laboratory
Small LIB (100 – 1500 mAh) for research can be produced by NEDO RISING project
Our LIB is comparable to commercial LIBs
Composition of pouch type battery
Waseda LIB with electrodes lab. made 55 mAh
Cathode = LiCoO2 /AB+KB/PVdF
Anode= Graphite /AB/PVdF
Separator single PP
Electrolyte 1MLiPF6/EC DEC=1 1 with VC
Waseda LIB with commercial electrodes
Cathode active material LiCoO2
Anode active material Graphite
Separator single PP
Electrolyte 1MLiPF6/EC DEC=1 1
Commercial LIB for electric assisted bycicle (5 Ah)
Cathode active material Mn based material
Anode active material Graphite
20
30
40
50
60
70
80
90
100
0 1 2 3 4 5 6
NormalizedCapacity%
C-rate C
Battery
System
Evaluatio
n
Materials
tery
tem
E
Anode Cathode Electrolyte
Feedback to development
of materials and system
Material evaluation as a actual battery
Advantage of our group
Non-destructive analysis
by electrochemical impedance spectroscopy
New material creation by electrochemical Nano-technology
Integration technology and system optimization
for battery performance
Our LIB production technique enables materials we developed to be evaluated as actual battery
Higher performance
than commercial LIB

6. One setmultiple sets
～5 Ah
Specification of lithium secondary batteries made by Osaka Lab.
～2.5 mAh～75 mAh
multiple sets
2～3Ah
70mm
×30～70mm
18 mm φ
70 mm
×70 mm
70 mm ×70 mm
70mm × 140 mm
Semi automatic assembly machine Handmade
～1.5 Ah
Capacity
LiCoO2/C
60 mm
×800 mm
One set
Electrode
Size
Slurry
preparation
Coater
Assembly
Sheets One set
Pouch Cell Cylindrical Cell Pouch Cell Pouch Cell Button Cell
Roll to Roll (W200mm)
Desktop Coater
Powder mixing/ Slurry preparation (0.5L～5L) (0.15～1L)
Mixer
Roll to Roll (W150mm)
Coating Duplex Duplex Duplex Simplex Simplex
Center of Innovation Program
Smart Life Support Innovation R&D Center
122014.12

7. Visualization of BEMS
Seminar room, Office room
Clean room
Electrode coating
Dry room
LIB assembling
Super dry room
Laboratory
Separated laboratories with
confidentiality
Industry-academia partnership project
room
Innovation design center〜
Waseda Smart Life Support Innovation R&D Center
（Final completion in December, 2014）
R&D Center
Hall
Center of Innovation Program
Smart Energy System Innovation R&D Center
13
Contents
• Introduction
• Design of Equivalent Circuit for Electrochemical
Impedance Spectroscopy on LIB
• Dependence of EIS on Temperature
• EIS for Degradation Analysis of LIBs
• Square Current/Potential-EIS
• Summary
14

8. Possible Phenomena relate to LIB performance
Phenomenon in LIB LIB performance
Electron Migration
・Electrode layer
・Current collector / Electrode
layer
・Current collector
Power decay
Capacity decay
Ion migration
・Electrolyte
・Electrolyte in electrode layer
・SEI
Power decay
Capacity decay
Electrochemical reaction (Charge
transfer)
・Active material / Electrolyte
(Active material / SEI)
Power decay
Capacity decay
Life deterioration
Safety deterioration
Diffusion in Solid of Active Materials
Power decay
Capacity decay
Cu current collectorAl current collector Electrolyte
Anode active material
Cathode active material
Electron conductive additive
SEI
SEI: Solid Electrolyte Interphase 15
Design of Equivalent Circuit for LIB
• Examples
– Solid-Solid contact interface
– Active material / Electrolyte
– SEI Active material
Electron conductive additive
Current collector
16

9. Design of Equivalent Circuit for LIB
17
SEI
Active material
Electrolyte
Li+
Li+
Li+
• Examples
– Solid-Solid contact interface
– Active material / Electrolyte
– SEI
Key phenomenon should selected
for practical application of EIS to LIB evaluation. 17
Nyquist plot of a Commercial LIB
Nyquist plot obtained from a LIB at 100% of SOC.
(Frequency range100 kHz ‐ 0.1 mHz)
<Conditions>
Equipment：Solartron SI1287, SI1252A
Charge‐discharge：Constant current (1 A)‐Constant
voltage (4.2 V kept until less than 1 mA).
Impedance measurement：Open circuit voltage at a SOC,
Amplitude 10 mV, Frequency range 100 kHz ‐ 0.1 mHz.
Feature 1
•High frequency (> 5 kHz): Inductive response
Feature 2
•Middle frequency (5 kHz - 1 Hz): Several
overlapped semicircles
Feature 3
•Low frequency (< 1 Hz): Diffusive response
and limiting capacitance
‐0.01
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0 0.01 0.02 0.03 0.04 0.05 0.06
‐Z" / Ω
Z’ / Ω
← 100 kHz
10 kHz →
← 1 mHz
1 Hz
↓
0.1 mHz →
Feature１
Feature 2
Feature 3
18

10. Fundamental Equivalent Circuit for Batteries
The equivalent circuit contains
 Charge transfer reactions and diffusions on anode
 Charge transfer reactions and diffusions on cathode
 Ionic resistance of electrolyte.
19
‐0.01
‐0.005
0
0.005
0.005 0.010 0.015
‐Z" / Ω
Z’ / Ω
○ Experimental Data
● Fitting
R2
Rs
CPE2
ZW2
R1
CPE1
ZW1
L0
R0
Fundamental equivalent
circuit with inductive element
Inductive response (Feature 1)
20

11. Equivalent circuit with inductive element
21
ZD（L-1）
L-2
L-1
L-1
ZD-1（L-1）
ZD-２（L-2）
Distributed
diffusion length
Uniform
diffusion length
Size distribution of active material
22

12. Equivalent circuit counting diffusion distribution
T. Osaka, S. Nakade, M. Rajamaki, T. Momma, J. Power Sources, 119, 929 (2003)
Equivalent circuit 2 can fit the impedance
responses of features 2 and 3 in a commercial LIB. 23
Solid Electrolyte Interphase on anode
Solid Electrolyte
Interphase (SEI) Desolvation Electrolyte
(Solvated ion)
Li+ migration in interphase
Migration
in electrolyte
Migration
in SEI
Diffusion
in graphite
http://www.jst.go.jp/kisoken/crest/report/sh_heisei10/shigen/ogumi.pdf
24

13. Equivalent circuit counting SEI
T. Osaka, T. Momma, D. Mukoyama, H. Nara, J. Power Sources, 205, 483‐486, 2012.
25
Residual Errors for the Impedance Data
LIB (0.85Ah), SOC100%
T. Osaka, T. Momma, D. Mukoyama, H. Nara, J. Power Sources, 205, 483‐486 (2012). 26

14. Contents
• Introduction
• Design of Equivalent Circuit for Electrochemical
Impedance Spectroscopy on LIB
• Dependence of EIS on Temperature
• EIS for Degradation Analysis of LIBs
• Square Current/Potential-EIS
• Summary
27
-0.03
0
0.03
0 0.03 0.06
-Z"[Ω]
Z’ [Ω]
-0.1
0
0.1
0.2
0.3
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
-Z"[Ω]
Z’ [Ω]
RS
RF
CPEF
RI
L
RA
CPEA
RC
CPEC
SEI Anode Cathode
- 20 ˚C
20 ˚C
Impedance Measurements at
Low Temperature as Useful Technique to Detect SEI
T. Momma, M. Matsunaga, D. Mukoyama, T. Osaka,
J. Power Sources, 216, 304, 2012.
Commercial LIB、0.83Ah、SOC 50%
28

15. Fitting Parameters under Temperature Control
Cell B、0.83Ah、SOC 50%
000
000
000
000
001
-30 -20 -10 0 10 20 30
Log(Resistance)[Ω]
□ Cathode
△ Anode
● SEI
000
000
000
001
010
-30 -20 -10 0 10 20 30
Log(Capacitance)[F]
Temperature [℃]
0
-1
-2
1
-3
0
-1
-3
-2
RS
RF
CPEF
RI
L
RA
CPEA
RC
CPEC
□ Cathode
△ Anode
● SEI
T. Momma, M. Matsunaga, D. Mukoyama, T. Osaka, J. Power Sources, 216, 304, 2012.
29
Contents
• Introduction
• Design of Equivalent Circuit for Electrochemical
Impedance Spectroscopy on LIB
• Dependence of EIS on Temperature
• EIS for Degradation Analysis of LIBs
• Square Current/Potential-EIS
• Summary
30

16. EIS Analysis for Cycling Degradation
31
D. Mukoyama, T. Momma, H. Nara, and T. Osaka,
Chem. Lett., 41, 4, 444 (2012).
-0.05
0
0.05
0.1
0.15
0.2
0.25
0.3
0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45
-Z"[Ω]
Z’ [Ω]
Whole resistance
represented as the real part
of whole cell impedance
Limiting capacitance
from low frequency
impedance plots
Cell C、0.85Ah、SOC100%
Whole resistance
represented as the real part
Limiting capacitance
31
T. Hang, D. Mukoyama, H. Nara, N. Takami, T. Momma, T. Osaka,J.
Power Sources, 2013.
LIB with Li4Ti5O12 Anode、4.2 Ah
Fig. Battery charge capacity with the
number of charge–discharge cycles.
Fig. Variation of the (a) resistance and (b)
limiting capacity with the number of charge‐
discharge cycles at DOD of 20%
Electrochemical Impedance Spectroscopy Analysis
for Lithium-Ion Battery Using Li4Ti5O12 Anode
32

17. Contents
• Introduction
• Design of Equivalent Circuit for Electrochemical
Impedance Spectroscopy on LIB
• Dependence of EIS on Temperature
• EIS for Degradation Analysis of LIBs
• Square Current/Potential-EIS
• Summary
33
-0.01
-0.005
0
0.005
0.01
0.015
0.02
0.005 0.01 0.015 0.02 0.025
-Z"/Ω
Z’ / Ω
1 mHz
1 kHz
1 Hz
Fig. Example of a commercial LIB impedance
response.
Battery Capacity:5Ah, Frequency range:10k – 1mHz, V0‐p = 5mV
Recent Progress of LIBs
Battery for power grid system
○The battery capacity: Larger
×The inner impedance: smaller
0.0001
0.001
0.01
0.1
1
10
0.01 0.1 1 10 100
Real part of impedance / Ω
Battery Capacity / mAh
Large‐capacity
LIB
10 year before
Present
Fig. Correlation of battery capacity to real
part of impedance 1k ‐ 1Hz.
Samples：Several commercial LIB cells
34

18. Concept of Battery Analysis
Conventional EIS
Square current EIS (SC‐EIS) for large capacity LIB
Input signal
High frequency range (Base model)
-0.005
0
0.005
0.005 0.01 0.015
-Z"/Ω
Z’ / Ω
Frequency response
Measure
Fourier Transform
Data processing
Input signal
-0.005
0
0.005
0.005 0.01 0.015
-Z"/Ω
Z’ / Ω
Frequency response
Measure
Data processing
0
0.2
0.4
0.6
0 200 400 600
|A|
Frequency [Hz]
|A|spectrum
0
0.005
0.01
0 200 400 600
|V|
Frequency [Hz]
|V|spectrumLow frequency range: less than 1 Hz
35
Application of (SC-EIS) to Analysis
for Degradation of Lithium Ion Battery
 Battery system
・ Power output：60W (4V, 5Ah, 3C)：Laminated cell × １
・ Nominal capacity：20Wh (4V, 5Ah)
・ SOC in commercial use：50%
 Charging/discharging system
・ HJ3010SD8 (Hokuto) ＋ 34410A (Agilent)×2(Current, Voltage)
・ Power control
 Control rate; per 10 msec
 Start to 100%; 1 msec
・ Property
 a switch that interrupts an electric circuit in the event of current cut‐
off.
 It takes 40 to 60 msec to return polarity.
Measurement specification
36

19. Square-Current EIS with High Frequency
Time / s
Current I / A
IB
IP‐P
IA
 tontoff
tr
ton = toff = 1, 10 msec
tr = 1 msec
IA = 1A
IB = 1mA
 = 20, 200 msec
f = 5, 50 Hz
IP‐P = 1 A
Range of high frequency：250～5Hz
37
To use another current waveform for the phase difference measurement
comparing that with high frequency, quasi sine wave current generated by putting
a multistage step of 50Hz was used.
Time / s
Current I / A
‐IA
IP‐P
IA

Range of low frequency：Less than 1Hz
Square-Current EIS with Low Frequency
38

20. Nyquist Plots
0
0.01
0.02
0.005 0.015 0.025
‐Z''/Ω
Z'/Ω
Sweep 10p/1d
0A±1A 1mHz
0A±1A 10mHz
0A±1A 100mHz
0A±1A 1Hz
0.5A±0.5A1Hz
0.5A±0.5A 5Hz
0.5A±0.5A 10Hz
0.5A±0.5A 16.7Hz
0
0.001
0.002
0.009 0.01 0.011 0.012 0.013
‐Z''/Ω
Z'/Ω
SC-EIS Results
Bode Diagram
0
0.01
0.02
0.03
0.04
0.0001 0.001 0.01 0.1 1 10 100 1000
|Z| /Ω
f / Hz
0
10
20
30
40
0.0001 0.001 0.01 0.1 1 10 100 1000
θ/degree
f / Hz
We realized the measurement of the frequency
response of the electrochemistry impedance
with charge‐discharge system and the simple
and low‐cost measuring equipment using the
digital multi‐meter.
41
Tuning of Measurement and Analysis Program
Low frequency
range: less than 1 Hz
High frequency
range (Base model)
42

21. Cutting-edge Data
‐0.002
0
0.002
0.005 0.007 0.009 0.011
‐Z” / Ω
Z’ / Ω
EIS
SC‐EIS
SC: 50 Hz, 5 Hz, 0.5 Hz
Measurement timing between current and voltage was
synchronized sampling frequency until 1 MHz.
Beautiful !!
43
The square wave impedance method (SW‐EIS) is
used similarly to the general FRA method. SP‐EIS
and SC‐EIS are proved to give the equal results to
that of FRA‐EIS. Especially, the square wave current
impedance method (SC‐EIS) works well to the large
capacity battery with low inner impedance .
Application of Square Wave Impedance to battery analysis
New Analysis of High Capacity LIBs with Low Internal Resistance
Summary: Square Current/Potential-EIS

22. Contents
• Introduction
• Design of Equivalent Circuit for Electrochemical
Impedance Spectroscopy on LIB
• Dependence of EIS on Temperature
• EIS for Degradation Analysis of LIBs
• Square Current/Potential-EIS
• Summary
45
Summary
• EIS for commercial Li‐ion batteries is able to be
analyzed with using the proposed equivalent circuit,
thus the degradation is estimated with this method
using non‐destructive evaluation.
• The Square Wave‐EIS method proposed showed a
result similar to that of general FRA method, especially,
the Square Current‐EIS method works effectively for the
battery system with lower internal impedance less
than a few m.
46

23. 47
Acknowledgement
for recent our staffs and students.
Karuizawa seminar House of Waseda univ 2014.8.
Thank you four your attention.
Battery Group Meeting at Kamogwa Seminar House of Wased Univ/ 2011.7.26.