Track 2: EV Technology for Specialty Vehicles:

Thermal and Electrochemical Modelling of Li-ion

Cells for HD xEVs

Jens Groot Ph.D.

ESS Specialist – Cell Characterisation & Modelling

Volvo Group Trucks Technology

Volvo Group Trucks TechnologyAdvanced Technology & Research, Jens Groot

2 2017-02-01

The Volvo Group

JV = Joint venture

SA = Strategic alliance

UD

Trucks

Dongfeng

Trucks EicherMack

Renault

Trucks

Nova

Bus

SDLG

Sunwin JV

Terex

Trucks

Prevost

Volvo

Trucks

Volvo

Penta

Volvo

Construction

Equipment

Volvo

Buses

JV SA

JV

UD

Trucks

Our mission

Driving prosperity through transport solutions

Our vision

Be the most desired and successful

transport solution provider in the world

Volvo Group Trucks TechnologyAdvanced Technology & Research, Jens Groot

3 2017-02-01

RESEARCH AND

TECHNOLOGY DEVELOPMENT

GROUP TRUCKS TECHNOLOGY

for the Volvo Group

Volvo Group Trucks TechnologyAdvanced Technology & Research, Jens Groot

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Challenges

Modelling Cells & Systems

– Empirical models

– Electrochemical models

– State-of-health / ageing

R&D Collaboration within

Swedish Electric & Hybrid Vehicle Center

Outline

Current Collector

Solid phase, electrode

Liquid phase, electrolyte

RSep

RCol

Liquid phase, electrolyte / separator

OCV

CDL

RCT

RSP

CPol

RPol

Rohm

OCV

CDL

RCT

RSP

CPol

RPol

Rohm

OCV

CDL

RCT

RSP

CPol

RPol

Rohm

OCV

CDL

RCT

RSP

CPol

RPol

Rohm

OCV

CDL

RCT

RSP

CPol

RPol

Rohm

Reaction Kinetics / Double Layer / OCV

Segment 1 Segment 2 Segment 3 Segment 4 Segment 5

Volvo Group Trucks TechnologyAdvanced Technology & Research, Jens Groot

5 2017-02-01

Wide range of vehicles…

Scope

Wide range of temperature & usage patterns

• 24/7 operation, -30°C…+50°C ambient

• Long-haul, regional, city, off-road

• Different markets, operators & routes

Volvo Group Trucks TechnologyAdvanced Technology & Research, Jens Groot

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Example: measured power for a power-optimised Li-ion cell

Scope

0 20 40 60 80 1000

100

200

300

400

500

600

700

800

SOC [%]

Pow

er

[W]

Measured Charge Power

2s charge, 40°C

10s charge, 40°C

30s charge, 40°C

2s charge, 23°C

10s charge, 23°C

30s charge, 23°C

2s charge, 0°C

10s charge, 0°C

30s charge, 0°C

2s charge, -15°C

10s charge, -15°C

30s charge, -15°C

2s charge, -30°C

10s charge, -30°C

30s charge, -30°C

0 20 40 60 80 1000

100

200

300

400

500

600

700

SOC [%]

Pow

er

[W]

Measured Discharge Power

2s discharge, 40°C

10s discharge, 40°C

30s discharge, 40°C

2s discharge, 23°C

10s discharge, 23°C

30s discharge, 23°C

2s discharge, 0°C

10s discharge, 0°C

30s discharge, 0°C

2s discharge, -15°C

10s discharge, -15°C

30s discharge, -15°C

2s discharge, -30°C

10s discharge, -30°C

30s discharge, -30°C

Volvo Group Trucks TechnologyAdvanced Technology & Research, Jens Groot

7 2017-02-01

Dimensioning / Basic reqs.

Battery Performance vs.

– Pulse Time

– Temperature

– SOC

– Age / State-of-health

Scope

Design

Dynamic battery response vs.

– Current

– Load cycles / vehicles

– Temperature / cooling

– SOC ranges

– Age / State-of-health

Can be retrieved by

extensive testing

Can only be retrieved through a

combination of testing, modelling

and validation

Volvo Group Trucks TechnologyAdvanced Technology & Research, Jens Groot

8 2017-02-01

Extensive testing – fast parameterization & validation

– >500h in test rig

– Test temperatures (typical): [-30 -15 0 +23 +40]°C

– SOC range: 0-100% in steps of 1-10%

– Current range: at least three, e.g. [-10 -5 -1 1 5 10] C-rate

Empirical Models

Volvo Group Trucks TechnologyAdvanced Technology & Research, Jens Groot

9 2017-02-01

Validation through GITT / pulses

Empirical Models

2.25 2.3 2.35 2.4 2.45 2.5

x 104

3.24

3.25

3.26

3.27

3.28

3.29

Time [s]

Voltage [

V]

CELLT12: Voltage comparison at 21C

Model

Measured

0 10 20 30 40 50 60 70 80 90 1000

5

10

15

SOC[%]

Err

or[

%]

CELLT12: 1Hz Filtered Voltage Error at 21C. Mean Error (optim/ext) = 0.06/0.39%.

Volvo Group Trucks TechnologyAdvanced Technology & Research, Jens Groot

10 2017-02-01

Empirical Models

0 500 1000 1500 2000 2500 30001.9

2

2.1

2.2

2.3

2.4

2.5

2.6

Time [s]

Voltage [

V]

ABT03: Voltage comparison at 24C

1675 1680 1685 1690 1695 1700 1705 1710 1715 1720 1725

2.1

2.15

2.2

2.25

2.3

2.35

Time [s]

Voltage [

V]

ABT03: Voltage comparison at 24C

0 10 20 30 40 50 60 70 80 90 1000

5

10

15

SOC[%]E

rror[

%]

ABT03: 1Hz Filtered Voltage Error at 24C. Mean Error (optim/ext) = 1.2/1.2%.

Analysis

Quantification Approval?

Verification

Volvo Group Trucks TechnologyAdvanced Technology & Research, Jens Groot

11 2017-02-01

Current Collector

Solid phase, electrode

Liquid phase, electrolyte

RSep

RCol

Liquid phase, electrolyte / separator

OCV

CDL

RCT

RSP

CPol

RPol

Rohm

OCV

CDL

RCT

RSP

CPol

RPol

Rohm

OCV

CDL

RCT

RSP

CPol

RPol

Rohm

OCV

CDL

RCT

RSP

CPol

RPol

Rohm

OCV

CDL

RCT

RSP

CPol

RPol

Rohm

Reaction Kinetics / Double Layer / OCV

Segment 1 Segment 2 Segment 3 Segment 4 Segment 5

Battery Modelling

Current Collector

Solid phase, electrode

Liquid phase, electrolyte

RSep

RCol

Liquid phase, electrolyte / separator

OCV

CDL

RCT

RSP

CPol

RPol

Rohm

OCV

CDL

RCT

RSP

CPol

RPol

Rohm

OCV

CDL

RCT

RSP

CPol

RPol

Rohm

OCV

CDL

RCT

RSP

CPol

RPol

Rohm

OCV

CDL

RCT

RSP

CPol

RPol

Rohm

Reaction Kinetics / Double Layer / OCV

Segment 1 Segment 2 Segment 3 Segment 4 Segment 5

Volvo Group Trucks TechnologyAdvanced Technology & Research, Jens Groot

12 2017-02-01

Battery Modelling

Current Collector

Solid phase, electrode

Liquid phase, electrolyte

RSep

RCol

Liquid phase, electrolyte / separator

OCV

CDL

RCT

RSP

CPol

RPol

Rohm

OCV

CDL

RCT

RSP

CPol

RPol

Rohm

OCV

CDL

RCT

RSP

CPol

RPol

Rohm

OCV

CDL

RCT

RSP

CPol

RPol

Rohm

OCV

CDL

RCT

RSP

CPol

RPol

Rohm

Reaction Kinetics / Double Layer / OCV

Segment 1 Segment 2 Segment 3 Segment 4 Segment 5

0 5 10 15 20 25 30 35-10

-5

0

5

10

Time [min]

Cu

rren

t [C

-rat

e]

Anode segment 1

Anode segment 2

Anode segment 3

Anode segment 4

Anode segment 5

Cell Current

Power-optimised LFP//graphite, +4C/-4C, 0-100% SOC, +29°C

Distribution of current →

Distribution of losses

Distribution of temperature

Distribution of ageing

Volvo Group Trucks TechnologyAdvanced Technology & Research, Jens Groot

13 2017-02-01

Battery Modelling

Current Collector

Solid phase, electrode

Liquid phase, electrolyte

RSep

RCol

Liquid phase, electrolyte / separator

OCV

CDL

RCT

RSP

CPol

RPol

Rohm

OCV

CDL

RCT

RSP

CPol

RPol

Rohm

OCV

CDL

RCT

RSP

CPol

RPol

Rohm

OCV

CDL

RCT

RSP

CPol

RPol

Rohm

OCV

CDL

RCT

RSP

CPol

RPol

Rohm

Reaction Kinetics / Double Layer / OCV

Segment 1 Segment 2 Segment 3 Segment 4 Segment 5

Distribution of current →

Distribution of SOC

Distribution of losses

Distribution of temperature

Distribution of ageing

Power-optimised LFP//graphite, +4C/-4C, 0-100% SOC, +29°C

Cathode Anode0

10

20

30

40

50

60

70

80

90

100

Sep

ara

tor

Ca

tho

de c

urr

en

t co

llecto

r

An

od

e c

urr

en

t co

llecto

r

Ele

ctro

de

SO

C [

%]

Start of discharge

Start of discharge

End of discharge

Start of discharge

End of discharge

Volvo Group Trucks TechnologyAdvanced Technology & Research, Jens Groot

14 2017-02-01

Fast-Charging of Large Energy-Optimised Li-ion Cells for Electrified Drivelines

Ageing & State-of-Health

Material Research-electrodes

-electrolytes

-electrochemistry

Modeling-physical models

-empirical models

-thermal models

-ageing models

Application-light-duty vehicles

-heavy-duty vehicles

-cell/module/system

Uppsala

University

KTH

Scania CV

Volvo Group

Volvo Cars

Chalmers

Volvo Group Trucks TechnologyAdvanced Technology & Research, Jens Groot

15 2017-02-01

Fast-Charging of Large Energy-Optimised Li-ion Cells for Electrified Drivelines

Ageing & State-of-Health

Ageing

0 200 400 600 800 1000 1200 1400 1600 180060

65

70

75

80

85

90

95

100

105

110

Capacity Throughput [No. of Full Cycles]

Capacity [

%]

EOL Limit

-1C/+2C 20-80%

-1C/+3C 20-80%

-1C/+4C 20-80%

Increasing charge rate

Simple cycles ’Mixed-mode’ cycles

Volvo Group Trucks TechnologyAdvanced Technology & Research, Jens Groot

16 2017-02-01

Fast-Charging of Large Energy-Optimised Li-ion Cells for Electrified Drivelines

Ageing & State-of-Health

Post-mortem analysisRaman spectroscopy

EC:Li+

EC

DMC DMC:Li+

Calendar, cell A

Calendar, cell B

XPS SEM & EDX

NMC NMCElectrolyte

Volvo Group Trucks TechnologyAdvanced Technology & Research, Jens Groot

17 2017-02-01

Fast-Charging of Large Energy-Optimised Li-ion Cells for Electrified Drivelines

Ageing & State-of-Health

ModellingThermal Model Electrochemical Model Ageing

Volvo Group Trucks TechnologyAdvanced Technology & Research, Jens Groot

18 2017-02-01

Jens Groot Ph.D.

ESS SpecialistVolvo GTT – ATR

jens.groot@volvo.com

http://www.volvogroup.com/en-en/about-us/r-d-and-innovations.html