LCVTP WS1 – Battery & Battery Packs
Workstream members
John Lewis, Tony Smith, Robinson Stonely,
Mark Tucker, Gary Kirkpatrick, Stene Charmer,
Salvio Chacko & Valerie Self
TMETC
Jeremy Greenwood & Kotub Uddin
JLR
Mark Amor-Segan & Yue Guo
WMG
Robert Ball
Ricardo
James Marco & Cip Antaloae
Cranfield
Presented by Valerie Self Tata Motors – WS1 Lead
Summary
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Workstream Goal and Structure
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Task Responsibilities
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Summary of WS1 Tasks
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Conclusions
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Questions
Workstream Goal & Structure
Workstream Goal
•
To develop modules suitable for
battery packs for GTVs
•
Source and validate suitable cells
and the hardware and software for
associated BMS
•
Develop processes & methodologies
to support workstream goals
Workstream Structure
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•
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Divided into nine sub-tasks
Each task has set of deliverables
Task deliverables have
interdependencies
Workstream Structure
Task 1.9 Packaging
Task 1.1 Validate Cell Claims
Task 1.2 Modelling
Task 1.7 Long term targets
Task 1.8 Recycling issues
Task 1.3 Testing
Task 1.5 Integration
Battery Management System
Task 1.4 BMS design
Task 1.6 BMS algorithms
Task Responsibilities
JLR
Tata
Ricardo
WMG
Cranfield
S
L
S
S
S
Validate Cell Claims
S
S
S
L
L
Battery Modelling
S
S
S
L
S
Characterisation & Accelerated Life
Testing
L
S
S
S
S
Validate BMS System Design
S
L
L
S
S
Pack Integration
L
L
S
S
S
Develop Suitable BMS Algorithms &
Hardware
S
S
L
S
S
S
S
S
L
S
Longer Term Targets for Next Generation
Technologies
L = Leader of Task
Recycling Issues
S = In Support
S
L
S
S
S
Module & Pack Concept Design
Task 1.1- Database of Li-ion Cells Suppliers
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Based on manufacturer’s data for 860 cells
•
Wide range of cells included (not just ‘EV’ traction cells)
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Includes original datasheets
•
Allows initial comparison of claimed performance, prior to more rigorous testing
Task 1.1- Report on Abuse Testing Methodology
Report allowing the initial comparison of
abuse test types
Further work to establish WS testing
methods
Task 1.2 - Battery Modelling
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Determine model requirements
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Select model architecture & tools
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Cell equivalent electrical circuit model
Dymola chosen as modelling tool
Cell model
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Literature review completed
Model is completed and parameterised against A123, EIG &
Dow Kokam cells
Pack model
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Takes into account design parameters, manufacturing
tolerances, interconnect impedances, cell chemistries,
calendar age and life cycle to allow predictions to be made.
Task 1.3 - Battery Testing
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Initial Cell characterisation testing
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Final Cell characterisation and project specific testing
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Cells chosen for module
Pulse Power Tests
Charge Retention Test
OCV vs. SoC Test
Cell Expansion Test
Thermal Characterisation Test
Storage Life Test
Energy Efficiency Test
Agreement on Real World Accelerated Life Testing Protocol
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•
Methodology is defined, IEC 62660-1
Cycle life testing will be run continuously
Task 1.3 - Battery Testing
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University of Warwick Li-ion testing facility
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Battery cell cycler: Bitrode MCV16-100-5 x 2
Environmental Chamber: Weiss Gallenkamp Votsch VC3 4060 x 2
High Temperature Battery Storage Chamber: Weiss Gallenkamp Votsch VT3050
Multi-channel temperature measurement system
Thermal Imaging Cameras FLIR T425 x 2
AC spectrum impedance tester
Weld Testing
Cell Expansion Testing
Task 1.4 - Validate BMS System Design
1
Current
In
1
Cell s1
Slave 1
Estimated SOC Energy etc
•
Master
Cell s2
Cell sn
•
Initial Requirements Specification for BMS
Generic requirements developed within WS1
Slave 2
•
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Slave n
•
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•
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BMS Concept FMEA
Developed by TMETC, JLR, Ricardo and WMG
in association with hardware and battery
integration suppliers
BMS Test Specification
Used to assess WS1 BMS hardware capabilities
Initial Functional Safety
Developed by TMETC & JLR to work towards an
ISO26262 compliant system
Assessment BMS Test Report
Report demonstrating the capability of the BMS
hardware, software and algorithms
Task 1.5 - Module Specification
Specification document that derives the
characteristics of the desired module
from a consideration of GTV
applications and the shortlisted cells.
The specification covers electrical,
physical, thermal and environmental
characteristics of the module, together
with safety features and the BMS.
Task 1.5 - Patent Report on Module &
Interconnect Design
Completed Espacenet searches by Keywords
or Applicant- then filtered down to 223 relevant
results
Output was presented in a very useable format as a Mindmap,
covering interconnects, cell, module and pack design.
Task 1.5- FE Analysis of Module CAD Design
Finite Element analysis of the 48-cell module
for static and dynamic loadings- both during
module construction and during vehicle service.
Loads transferred to individual cells were
modelled.
Peak cell acceleration
300g over 3ms.
Highest accel seen on
RH side as closing
velocity increases with
rotation
Drop 100mm at 50
Module deforming during
simulated 100mm drop
test
Task 1.5 - Distribution of Modules
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Report has considered the options for
distributed packs
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Series vs. parallel modules
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Switching, fusing, interconnection options
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Compliance with standards, cell
manufacturers’ recommendations,
reliability, cost, weight…..
ECE/TRANS/WP.29/2010/52 SAE J2289
SAE J2344
•
Report concludes series connection lower
risk
Task 1.5- Interconnect Testing
• Interconnect materials have been chosen
to represent the chosen cell and
interconnect geometry
• 160 samples have been joined using ebeam and ultrasonic welding, soldering,
clinching and gluing on different tab
materials
• Testing has shown no overall ‘best’ joining solution
• Some techniques (ultrasonic welding, clamping)
showed lack of maturity in process settings and
would need to be optimised for a specific tab
application
• Some (gluing, soldering) had more inherent
difficulties in application
1.5 Thermal Management Strategy
• Maintain cell temperature at around 20°C to ensure safety, performance and life
• Requirements influenced by cell choice, vehicle operating environment and duty cycle
• A flexible and scalable module should be capable of accommodating a number of thermal management
solutions to optimise system efficiencies (energy, mass, volume, cost)
• Thermal management elements
• Inter-cell Phase Change Material (PCM)
• Inter-cell Heat Transfer Plate
• Inter-cell Active Cooling Plate
• Module base / side plate with Active
•
•
Cooling
Initial module is designed around a 2C maximum
discharge rate (EV)
Analysis to determine requirements for 4C and
10C applications
Inter-cell active cooling plates
Inter-cell HT plates + PCM + active base plate
Inter-cell HT plates + active base plate
PCM
No cooling
1
2
4
Maximum Discharge Rate [C]
10+
Thermal Pack Model Simulation
TMETC have developed a Li-Ion pouch cell electro thermal 3D CAE model
• It allows engineers to simulate heat generation as a function of electrical discharge/SOC
• It is an insightful design tool, facilitating the virtual evaluation and development of battery
thermal management systems prior to sourcing hardware/test
Task 1.6 Develop BMS Algorithms/Hardware
Hardware for Master & Slave
and associated embedded
software with integrated SOC
estimation
File: A10_NEDCx3_41%SOC_020610_log3
20
3.7
10
Load Current - [A]
Terminal Voltage - [V]
State-of-Charge Comparison: Commercial BMS v EKF
3.75
3.65
3.6
3.55
3.5
0
1000
2000
3000
-20
0
1000
2000
3000
4000
50
State-of-Charge - [%]
Temperature - [oC]
-10
-30
4000
25.8
25.6
25.4
25.2
25
0
0
1000
2000
3000
4000
Commercial BMS
EKF
45
40
35
30
25
0
1000
2000
3000
4000
Graph shows a cell being discharged
The WS1-developed BMS is shown to give
a more realistic step change and is far less
noisy than the commercial BMS
Task 1.7- Long-Term Targets & Next Generation
Technologies & 1.8 Recycling Issues
1.7 Long Term Targets
Report analysing the likely OEM demand for EV
batteries by 2020, and the required changes in battery
capacity, power, weight, lifetime and recycling needs
1.7 Next Generation Technologies
Forward-looking report covering the likely
developments in traction batteries by 2020
1.8 Battery Recycling Issues
Report showing potential range of 2nd life
usages adding value for vehicle OEM
battery packs. Report highlights barriers to
be addressed and issues with battery cell
recycling
Task 1.9 –Tata & JLR GTV Battery
Concept Packaging
Tata Battery Concept Packaging
• Battery packaged centrally under floor
• EV Target = 25.5 kWh, 320V Nominal
• WS1 Module Solution:
> 3x 10S4P modules +
> 3x 22S4P modules
• Total Pack: 96S4P (25.3 kWh, 317V
Nominal)
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Battery packaged under floor together with
APU fuel tank
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RE-EV Target = 12.75 kWh, 320V Nominal
WS1 Module Solution:
> 5x 20S2P modules
Total Pack: 100S2P (13.2 kWh, 330V
Nominal)
•
JLR Battery concept Packaging
• Target = 12kWh useable
• Target = 360V
• Use 475.2V (144s1p)
Task 1.9 Concept Module
• Hardware build requirements
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Mini modules (2P, 3S) for abuse testing
• Thermal shock
• Thermal runaway
• Propagation
• Spare
1
1
1
1
• Full modules (2P, 12S) for dynamic testing
• Mechanical shock 3
• Vibration
1
• Demonstration unit 1
(Note: Demonstration unit is a fully functioning battery
module complete with wiring harness)
Conclusions
Modelling
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Initial cell and pack models have been created to simulate performance which are suitable
for further development
Testing
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Results from comprehensive cell testing will provide valuable information on comparative
performance for range of cells
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Performance and abuse testing
Battery Management System
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Initial work on algorithms, hardware and software for a cell agnostic battery management
system has been completed which is suitable for further development
Module
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Phase 1 design and feasibility of the module concept has been delivered
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This will provide flexible design to meet pack requirements of JLR and Tata GTV’s
Questions
Thank You
Any Questions?