1. Key Technologies for Optimizing
Lithium Battery Cost-Effectiveness
Eugene Liu
Director of Engineering and Product Development
Shanghai Advanced Traction Battery Systems, Inc.
Mujeeb Ijaz
Vice President, Cell Product Development
A123 Systems, Inc.
Green Fuels and Vehicles China 2011

2. Components of battery cost
– Purchase cost
• $/kWh
– Ownership cost
• Cycle life
• Warranty
• Repair costs
– End of life disposal costs
ATBS Confidential

3. Battery Purchase Costs
Nameplate vs. Usable Energy, $/kWh
kWh Nameplate energy
Unused due to
safety and life
at high SOC
$/kWh - usable Usable energy
energy $/kWh - nameplate energy
(what you can (what you pay for)
actually use)
Unused due to
power at low SOC
Usable energy depends on battery manufacturer’s cell technology
3

4. Usable Energy Example
160 $8000
16kWh total
140 $500/kWh
Unused due to
$5700
120 safety and life
at high SOC 11.4kWh total
$500/kWh
100 $4400
Usable energy 8.9kWh total
80 50% of total $500/kWh
8kWh usable Usable energy
60 $1000/kWh 70% of total Usable energy
8kWh usable 90% of total
40
$710/kWh 8kWh usable
Unused due to $560/kWh
20
power at low SOC
0
The key to optimizing battery pack costs is to increase usable energy
4

5. Maximizing Usable Energy
Key elements
Flat power vs. SOC curve = lower SOC setpoint for HEV operation = higher useable
energy
Superior abuse tolerance allows charging to high SOC = higher useable energy
Excellent deep-discharge cycle life = higher SOC swing = higher useable energy
Typical More Useable Energy
Pulse power
Pulse power
charge- charge- charge- charge-
sustaining depleting sustaining depleting
0 20 40 60 80 100 0 20 40 60 80 100
SOC SOC
50-60% SOC swing 70-90% SOC swing
5

6. Reduced Ownership Costs
• Long cycle life
1C-1C, 100% depth of discharge (DOD) cycling
120% 120%
Discharge Capacity (% initial)
DC Impedance (% initial)
100% 100%
80% 80%
60% 60%
40% 40%
20% 20%
0% 0%
0 2000 4000 6000 8000 10000 12000
Cycle Number

7. Reduced Ownership Costs
• Fully validated and proven
battery pack components
– Cells
• Base chemistry in production since
2008
• Over 20 million miles of continuous
revenue service
– Modules
• Tested to all UNDOT and
FreedomCar safety standards
• Extensive DFMEA and DVP&R
requirements
• Mass production launched in 2010
– BMS
• Validated to all automotive
durability and EMC standards

8. Reduced Ownership Costs
• High reliability design features
– 100% welded module interconnects (bi-
metallic bus bars, voltage sense leads)
– IP67-compliant pack housing design
– Hardware based high voltage interlock (relay
to avoid current pass through interlock)
– Pre-charge resistor protection from vehicle
bus shorts
• Pack system design with global automotive
industry-grade components and design
methodology

9. Battery Pack Component Costs
Battery pack cost breakdown
% of total battery pack cost
Need to focus on reducing
costs of pack components
Time
Cell costs will continue to decrease in future years

10. Reducing Battery Pack Costs
• Increased scale of
production
through
standardized
components
applied to each
battery pack
– Standardized
Scalable Prismatic
Modules
– Component
sourcing
leveraging global
volumes

11. Reducing Battery Pack Costs
Scalable family of battery
modules using common
components
Flexible Module
Locations and
Orientations
11

12. Reducing Battery Pack Costs
Using common building blocks in configurations to suit any application
xSyP Scalable Electrical Distribution Battery Control HV Service
Prismatic Module Systems Module Module (BCM) Disconnect
(Contactor, Current Sense, Pre-charge)

13. Reducing Battery Pack Costs
Customized Pack Components
Local China sourcing with Global
Quality and Design Standards
Lightweight Enclosures
High Voltage Wiring
Integrated Battery
Thermal Management
Enclosure Mounting
and Reinforcement
ATBS Confidential

14. Future Cost Reduction Roadmap
• Increased Energy Density
Battery Cells
• Increased Economies of
Scale
• VA/VE design practices
and lessons learned
• Reduced Manufacturing
Costs through DFM/DFA
ATBS Confidential