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Evlib part 2
1. This is Part 2 of the Presentations from the
EV Li-ion Battery Forum 2009
Forum Day 1 & 2
September 2009 Shanghai
Battery
Join in the discussion
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2.
3. Lithium Ion Battery and Electric Cars
Shanghai Sept 2009
Dr. Sankar Das Gupta
CEO , Electrovaya
• Climate Change 900 million vehicles
worldwide rely on
• Urban pollution fossil fuels
• Rising oil prices 50 - 70 million new
• Energy security vehicles on the road
each year
• Healthcare costs
85 Million Barrels
• Government initiatives of oil Burnt every
day
4. “It’s the batteries, Stupid”
The Honorable R. James Woolsey
The Honorable George P. Shultz
Co-Chairmen
Notes: (1) James Woolsey – former CIA Director
(2) George Shultz – former US Secretary of State
Electric Vehicle Components Unnecessary Internal Combustion Components
Battery System
Gas Tank
Engine
Electric Motor Transmis
sion
Muffler
Fuel reformer
Onboard Charge &
Motor Controller Oil Lines
Oil Pan
Water Cooling system
Catalytic Converter
Electric drive train
Fuel Injection System
Various Auxiliary System
5.
6. Nanotechnology
A 30 kWh system (e.g. small BEV) requires
240 x Electrovaya
35Ah cells
7120 x 18650 cells
(commercial phosphate)
3390 x 26650 cells
(commercial phosphate)
8. • Most of world Lithium Ion Battery production
uses organic liquid NMP (N- Methyl Pyrollidone)
• NMP recently suspected of reproductive Toxicity
(birth defects) California 2001, EU 2003
• Electrovaya – Unique Production Technology
does not use NMP
“Zero Emission Manufacturing for Zero
Emission Vehicles”.
9.
10. Control
Distributed Intelligence
Intelligence
Battery System
Battery Engineering Team
Thermal Engineering Team
Power Electronics Team
Mechanical Engineering Team
Electrical Engineering Team
11. 1. Mississauga, Ontario Canada
2. New York State, U.S.A.
3. Licensee, Miljobil Joint Venture
- Norway
Strategic Implications of Unique Manufacturing:
• Zero emission manufacturing process - Thus can manufacture anywhere – urban areas
(Toronto), countries (Norway) with minimal environmental footprint
• Capital cost for Manufacturing Plant is lowest for the industry - Thus can expand more
cost effectively
Mississauga, Ontario Canada
12. Production Flow
Pre-commercialization Activities
Cell Mfg. Module Build integration
System design system build verification
Commercial
Systems Engineering (Engineers, Scientists, Technicians)
Type of Labour Required
Battery R&D Team (Scientists, Engineers, Technicians)
Thermal Engineering Team (Engineers, Technicians)
Power Electronics Team (Computer Scientists, Engineers, Technicians)
Mechanical Engineering Team (Scientists, Engineers, Technicians)
Electrical Engineering Team (Engineers, Electricians, Technicians)
Mechatronics Team
iterative
work
Battery Electric Vehicles
Production : USA, Canada,
Norway
Plug-in Hybrid Electric Vehicles
Passenger Delivery Vans Off-Road maya-300
OEMs & Buses
Cars Urban cars
35. Cathode Voltage Specific Price Application Safety
vs Graphite Capacity
LiCoO2 3.7V 140Ah/kg $35/kg Consumer Low
LiNoCoMn 3.6V 155Ah/kg $24/kg Consumer mid
Powertool
LiNiCoAl 3.55V 170Ah/kg $26/kg Consumer Low/mid
Industial
LiMn2O4 3.8V 110Ah/kg $12/kg Powertool High
Vehicel
LiFePO4 3.2V 150Ah/kg $30/kg Powertool High
Vehicel
Voltage Specific Price
vs Graphite Capacity
Anode Graphite 0V 330Ah/kg $10/kg
Hard Carbon 0.3V 250Ah/kg $40/kg
Li4Ti5O12 1.3V 160Ah/kg $25/kg
Graphite Anode
36. Hard Carbon Anode Li4Ti5O12 Anode
Si
Si
Cu foil
nano-Si/C After discharging
Electrochem. agglomeration
H. Li, X. J. Huang et al,
Electrochemical and Solid-State Letters, 2 (11) 547-549 (1999)
38. 1
2
3
4
5
6
7
8
LFP/Graphite
*Patent licensing fee is not included
39.
40. Tianjin Lishen Battery Joint-stock Co.,Ltd
Zhang Na
2-3 Sep, 2009 EV Li-ion Battery Forum, Shanghai, China
Outline
41. Background-Key Materials Challenges
Safety The number one concern for passenger vehicles
Availability Meet a wide temperature range of -30 to 60
Durability Cycle and calendar life must allow for 10~15
years of battery operation
Cost Batteries for EV with large batteries require low cost
Cathode Chemistry in Lishen
KPI of Cathode Materials
Voltage Capacity /
Cycle Life Cost Safety
Range/V (mAh/g)
LiMn2O4 3.0-4.2 100 120 Good Low Better
LiFePO4 2.0-3.6 130 150 Excellent Low Excellent
NCM 2.5-4.2 150 Better High Good
NCA 2.5-4.2 150 Better High Good
•At least four different cathode chemistries are being considered in power battery
•NCA and NCM are the choices for high energy density
•LFP shows the lowest energy density due to low voltage and low material density
42. Safety of Cathode Material
DSC of LiNi1/3Co1/3Mn1/3O2 LiMn2O4
LiFePO4 and Electrolyte at 4.3V
•Most cathode materials exhibit a strong exothermal reaction with the electrolyte in
the charged state which can lead to a thermal runaway of the battery
•LFP is completely stable and allows the development of an intrinsically safe cell
Study on LiFePO4 in Lishen—Basic Performance
Energy Type Power Type
Items A B C D E F G H
Surface area (m2/g) 9 11 16 10 14 18 15 14
Tapped density (g/cm3) 0.8 1.0 0.9 1.1 1.0 1.0 1.0 0.6
Particle size (μm) (D10) 2.2 1.5 0.6 1.1 0.8 0.75 0.2 0.2
(D50) 5.4 3.4 2.3 4.2 4.5 5.1 0.8 0.6
(D90) 9.1 5.9 11.2 10.3 12.2 16.6 4.8 5.0
Moisture (ppm) 420 800 300 500 1100 100 410 700
Discharge capacity (mAh/ 148 150 145 148 145 143 143 152
g)
Processability Hard Hard Hard Hard OK OK Hard Harder
43. Study on LiFePO4 in Lishen—SEM
A B
C D
Study on LiFePO4 in Lishen—SEM
E F
G H
44. Study on LiFePO4 in Lishen—Discharge Performance
Discharge Performance:
A E B C D F
Study on LiFePO4 in Lishen—Cycle Life
Cycle Life( According to cycle life trend line): B C A E D
45. Study on LiFePO4 in Lishen—Discharge Performance
Discharge Performance:
G E
Study on LiFePO4 in Lishen—Safety performance
No Hot Oven Nail Penetration No
Explosion 150 /10min Nail: 3- 8mm, Explosion
No Fire Speed:10-40mm/s No Fire
No No
Explosion Over Safety & Abuse Over Explosion
No Fire Discharge Testing Charge No Fire
1C/10V
No No
Explosion Crush Short Circuit Explosion
No Fire No Fire
All the Materials are Safe!
46. Anode Chemistry in Lishen
Properties of anode materials
Item MCMB HC SC LTO
Structure
SEM
KPI of anode materials
Particle size Capacity Tap Density/
Advantage Disadvantage
D50/(μm) /(mAh/g) (g/cc)
Graphite Low cost; Low temp.;
8.104 300 1.3
(MCMB) High capacity Rapid charge
Energy; Initial
Hard High Power;
9.146 430 0.9 Longevity
Efficiency; low
Carbon tap density
Low energy
Soft
11.216 360 0.8 Low cost; Longevity density; low tap
Carbon density
High Power;
Low energy
Li4Ti5O4 9.7 150 1.2 Longevity
density
Low Temp.; Safety
47. Charge curves of anode materials
No SEI forming, which can
improve the low temp. electron
conductivity. the voltage Vs. Li is
Anode electrode Potential (V)
1.5V, which can effectively avoid Hard carbon has the excellent
the creating of the lithium specific capacity, and the charge
dendrites. and discharge curve shows good
gradient, which is propitious to
estimate the SOC of the battery .
1.5V Vs Li
LTO
Hard Carbon
The properties of soft carbon
Soft Carbon is between hard carbon and
artificial graphite.
Graphite
0.1V Vs Li
Charge Capacity (mAh)
Electrochemical performances—rated discharge
Because of the intrinsic properties,
hard carbon is benefit to be
discharged at large current. The
hard carbon displays the higher
voltage than soft carbon and
MCMB at high rate discharge.
48. Electrochemical performances—rated charge
LTO shows excellent high rate
charging property, which is
better than HC and SC, and the
high rate charging capacity of
the MCMB is the least.
Time of charging to 90%SOC (10C)
Anode Time/min
MCMB 12.8
HC 7.3
SC 5.4
LTO 5.6
Electrochemical performances—cycle life
49. Low temperature performance
Conclusions
Batteries are the primary barrier in making electric-drive vehicles
possible. Li-ion batteries can best meet the electric-drive challenge;
LiFePO4 is an intrinsically safe system with good cycle life. At present
LiFePO4 platform is one of the best choice for EV/HEV application in
Lishen;
MCMB and hard carbon are used in Lishen present EV/ HEV cell
products; Li4Ti5O12 has higher rate charge ability (at low Temp. vs. AG) ,
so it seems that Li4Ti5O12 is the best choice for next generation HEV
application;
Raw material is one of the key premise for good battery, but the
electrode process is a big challenge for battery maker due to the property
of LiFePO4. Lishen has sound base and enough manufacture experience
to penetrate the EV market.
65. How can we insure a safe and optimal operation of a
power source or energy storage (PS/ES) system?
Field testing?
Laboratory testing?
Modeling & simulation?
All of the above?
What tools do we need to reach that objective?
Model/simulation? Diagnosis? Prognosis?
Are they easy to handle?
Can they be used in real time ?
Can they be used to forecast the available capacity ?
How to understand field data?
Analyze the duty/generation cycle
Link usage (duty cycle) to size &
performance of the PS/ES system
Data collection Allow accurate sizing of the battery pack
for geographically-dependent duty cycle
Pattern
Recognition
Duty cycle
analysis
66. Data collection Event D, high wind speed,
low gusts distribution
Pattern
Recognition
Duty cycle Event cycle
analysis analysis
Event forecasting
How to understand battery
degradation ?
Battery electrochemical behavior is:
Rate dependent
Small scale tests
Temperature dependent Specific protocols
Age dependent
Need to test the cells under Performance Rate, T, …
appropriate protocols under load effects
Derived from representative usage
schedule (rate, temperature)
Matrix of different parameters
Rate
Pulses
Temperature
…
67. Degradation is often complex
Need a reference point (SOC tracing)
Need in situ characterization
Incremental capacity analysis
Close-to-equil. OCV analysis Small scale tests
Specific protocols
Life & degradation
mechanisms
Single cell model
Derived from performance tests
Small scale tests
Specific protocols
Cell performance Rate, T
Performance
model effects
under load
ECM approach: accurate & not computation intensive
68. Single cell to pack modeling
Accommodate cell-to-cell variations
Adapt to topology
Small scale tests
Specific protocols
Cell performance Rate, T
model Performance
under load effects
Pack model Cell to cell variations
Diagnostic and prognostic tools
Developed from knowledge in
single cell testing and analysis
Nominal vs. anomalies
ID & Quantification
Small scale tests
Specific protocols
Cell performance Rate, T
Performance
model effects
under load
Pack model Cell to cell variations
Diagnostic model
Life & degradation
Prognostic model mechanisms
69. Diagnostic and prognostic tools
V,SOC
Real time data
I,T,SOC,SOH Analysis
and
V,SOC prognostic
module
70. Representative
usage schedule
Small scale tests
Data collection
Specific protocols
Pattern Cell performance Rate, T
Performance
Recognition model effects
under load
Pack model Cell to cell variations
Duty cycle Event cycle
analysis analysis
Diagnostic model
Life & degradation
Event forecasting Prognostic model mechanisms
More details ―
Roadmap
M. Dubarry, V. Svoboda, R. Hwu and B.Y. Liaw, “A roadmap to understand
battery performance in electric and hybrid vehicle operation,” J. Power Sources
174 (2007) 366.
M. Dubarry, N. Vuillaume, B.Y. Liaw, and T. Quinn, “Vehicle evaluation, battery
modeling, and fleet-testing experiences in Hawaii: A roadmap to understanding
evaluation data and simulation” J. Asian Electric Vehicles 5 (2007) 1033.
Event pattern recognition
B.Y. Liaw, M. Dubarry, “From driving cycle analysis to understanding battery
performance in real-life electric hybrid vehicle operation” (invited) to the Special
Issue on Hybrid Electric Vehicles, J. Power Sources 174 (2007) 76.
Battery Analysis
M. Dubarry, V. Svoboda, R. Hwu and B.Y. Liaw, “Capacity and power fading
mechanism identification from a commercial cell evaluation,” J. Power Sources
165 (2007) 566.
M. Dubarry, V. Svoboda, R. Hwu and B.Y. Liaw, “Capacity loss in rechargeable
lithium cells during cycle life testing: The importance of determining state-of-
charge” J. Power Sources 174 (2007) 1121.
Modeling
M. Dubarry and B.Y. Liaw, “Development of a universal modeling tool for
rechargeable lithium batteries,” J. Power Sources 174 (2007) 856.
71.
72. Troy A. Hayes, Ph.D., P.E.
General Manager
Exponent China
+1 (650) 688-7127 (US)
+86 (571) 2802 1727 (China)
thayes@exponent.com
September 3, 2009
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Who We Are
• Professional services firm
• Engineering & scientific consulting
• 650+ consulting and technical staff
• Best known for analyzing accidents
& failures
• Design and manufacturing
consulting based on FA experience
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73. Outline
• Technologies used for identifying defective
cells
– X-Ray
– CT Scanning
– Hi-Pot testing
– OCV
– Sorting
– Imaging laser tab welds
– Tab-to-cell impedance (soft pouch)
• Maintaining your brand’s trust
– Recalls – when and why?
– Managing a recall
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74. X-Ray
• X-Ray is useful as a 100% inspection
procedure to verify proper anode/cathode
alignment
– Note: this is not 100% accurate
• X-Ray is also useful when used on a sampling
basis (using both is most desirable)
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X-Ray
Ni tab kink
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75. X-Ray
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CT Scanning
• CT Scanning can be used on a sampling basis
to evaluate:
– Metallic contamination
– Holes in active material
– High-density spots in active material
– Wrinkles in electrodes/current collectors
– Delamination of electrodes
– Detailed alignment
– Deformation of windings associated with tabs,
bends etc.
• Disadvantages:
– Slow for a complete scan (7 hours for an 18650)
– Expensive ($250K USD for a good machine)
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76. CT Scanning
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CT Scanning
• Cu dissolution
due to
repeated over-
discharge
• Cathode
delamination
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77. Hi-Pot Testing
• How were the Hi-Pot values chosen?
– Need a properly-designed DOE
• Metallic particle size/type
• Voltage level and application time
– Will vary with capacity/size
• Hi-Pot failures
– Data analysis
– Failure analysis
– Closed-loop corrective action
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OCV Testing
• How are the limits chosen?
– IEEE 1725 5.5.7
• Data analysis
• Failure analysis
• Closed-loop corrective action
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78. Sorting
• Why sort?
• Do you really know what causes the variation
between cells of various classes?
– Loading versus other properties
– Self discharge rate
• Is it possible for two independent causes to
create a cell of a particular class?
– If so, cells of one class may age differently
Cap 2,000 – 2,150 2,151 – 2,300
Voltage mAh mAh
V 3.82V Grade B Grade A
3.82 > V 3.77 Grade D Grade C
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Laser Weld Visual Inspection
• Entirely dependent on operator skill
• Is the visual inspection reliable?
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79. Impedance Measurement Between
Tab and Cell (Soft Pouch)
• When the inner polymer layer on the Al
pouch is compromised, a current
leakage path can occur
– Corrosion
– Gas generation
– Cell swelling
– Electrolyte leakage
• Compromised pouches can be identified
during production by measuring the
impedance between the negative tab
and the Al pouch after cell formation
and aging
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Part 2: Maintaining Your Brand’s Trust
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80. Maintaining Your Brand’s Trust
• Recalls are for the consumer’s
protection
• Recalls must be properly managed
• Recall as soon as possible – don’t wait
• Recall everywhere, not just where you
are required (e.g., by the CPSC)
• Consumers will have more confidence
in your brand if they know you are
acting in their best interest
• Communicate to the customer
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Limiting a Recall – TRACEABILITY
• Tracing all material lots and equipment is
extremely important!
– Cap assemblies
– Electrode batches
– Current collectors
– Slitting blade number
– Winding machine
– The more detail, the better
• Remember, most date codes disappear during
a thermal runaway event
– Can you differentiate dates and machines by
something internal to the cell?
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81. Data Analysis
• Need to consider
– End of life
– Time in service at time of incident
– Geography and power type/stability where
incidents occur
– Differences in population versus failure rate
(e.g., type of charger, etc.)
– Changes on manufacturing line
– Material changes
– Design changes
– Failure rates (Hi-Pot, OCV, etc.)
– Other factors
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Data Analysis
Expected Number of Failures
per Million Cells
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82. Timeline for Possible Contributing
Factors
2007 2008 2009
11 12 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7
Factor A
Factor B
Anode material B
Cu Foil B
Can vendor B
Winder #2 in use
Winder #16 in use
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Summary
• Technologies used for identifying defective
cells
– X-Ray
– CT Scanning
– Hi-Pot testing
– OCV
– Sorting
– Imaging laser tab welds
– Tab-to-cell impedance (soft pouch)
• Maintaining your brand’s trust
– Recall if necessary
– Manage the recall and communicate to the customer
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Make your product as traceable as possible
83. Questions?
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Cell and Battery Pack Analysis, Including:
Auditing, Failure Analysis, Design Review, Testing, CTIA
Certification and Regulatory Consulting
24 Offices Worldwide
Boston, Los Angeles, Phoenix, San Francisco and China
+1-888-656-EXPO (US) +86 571 2802 1788 (China)
www.exponent.com/batteries www.exponentchina.com
info@exponent.com exponentchina@exponent.com
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