Batteries and Battery systems State of Charge

Batteries and Battery systems State of Charge

POLITECNICO DI BARI-SMART GRID SEMINARY
E-MOBILITY
Battery technique in E-mobility
Dr.-Ing. Pio Lombardi
Fraunhofer-Institut für Fabrikbetriebund Automatisierung IFF
Bari 02-03.02.2012
Structure
 Introduction
 Battery technique
 Battery test technique
 Battery and battery systems
2
Elektromobilität
Introduction
Developing and market
 Development since 20th century
(1)

1948 maintenance free battery (Neumann)

In the 70th and 80th development for mobile applications (NiMH)

1991 Lithium-Ions cells

2003 rapid growth in Asia (China, Korea, Japan)

European and American Firms in niche applications (traction)
Marketshare of secondary cells, Quelle: Seeking Alpha, Umicore
(1)- A. Jossen, W. Weydanz „Moderne Akkumulatoren richtig einsetzen“
Global Marketshare of Battery Producers (CYcalender year) Quelle: batteryuniversity.com
3
Elektromobilität
Introduction
battery application areas
 Developing for high power batteries

After introduction of hybrid vehicles (12kWh)
Applications and utilized battery-technologies, vgl. (1)
applications
Lead
NiCd
Need of high charge and discharge
power
Starter battery
X
x

Trends to lithium based systems
Hybrid vehicle

Need of battery energy management

Electric traction
X
Solar application
X
equipments
Camera, mobile
phones
NiMH
LiIonen
X
x
X
X
x
x
X
X
Consume
weighting of criteria of batteries for elektromobility Quelle:
Frankenberg 2010
Primary
cells
X
(1)- A. Jossen, W. Weydanz „Moderne Akkumulatoren richtig einsetzen“
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Elektromobilität
Introduction
battery application areas
 Traction application

Secondary elements

High voltage plants

Hogh current

Volume and weight
Overview of voltage levels and power densities for traction applications
Application-Areas of batteries
Quelle: G. Schädlic
Hoppecke, 2010
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Elektromobilität
Battery technique
Nominal values
Nominal voltage different batteries
 Nominal voltage
Nominal voltage per cell
Voltage
Medium voltage by discharging under
nominal conditions
Lead batterie
2,0V
NiCd-Battery
1,2V

Nominal voltage is defined
NiMH-Battery
1,2V

Nominal voltage can increase improving the
technology (i.e. Li-Ion)
Na/NiCl (ZEBRA)
2,58V
LiFePO4-Battery
3,3V
Li-Ions Battery
3,7V

Nominal current and temperature for different
applications Source: A. Jossen, W. Weydanz „Moderne Akkumulatoren richtig
einsetzen“
t
 Nominal capacity
CN (TN )   IN t   dt
o
Anwendung
Nominal
current
Nominal
temperature
Starter battery
0.2C-Rate
20°C
Stationary Battery
1/20C-Rate
27°C
Traction battery
1/5C-Rate
30°C
Solar battery
1/100C-Rate
25°C
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Elektromobilität
Battery technique
Capacity and efficiency
13
 capacity
Usable charged amount

Depends on discharge current, temperature and
age conditions
Spannung [V]
12

t
C( )   I t   dt
10
15,5A
20A
29A
40A
9
8
o
0
1
2
3
4
5
Zeit [h]
Measured discharging-curve of a plumbaccumulator
16
Strom [A]
Ratio between discharged energy an EE and charged
energy EL
16
12
12
8
8
4
Wh 
EE
EL
4
Strom
Spannung
0
0
2
4
0
8
6
Zeit [h]
Measured Loading-curve of a plumb-accumulator
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Elektromobilität
Spannung [V]
 efficiency

11
Battery technique
Energy and power
 Energy and power specific data

Valutation of the technology

Rapresenation as Ragone-Diagram
Ragone Diagram for different storage
technologies Source: Maxwell Technologies
 Typical specific value

Specific Energy between 20 and 200Wh/kg

Specific power up tp max. 5kW/kg

Specific energy content in volume between
50 bis 500 Wh/l
Ragone Diagram for battery technologies
Batterietechnologien Source: GAIA Advanced Lithium Battery Systems 2007
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Elektromobilität
Battery technique
State-of-charge
 Charging condition: State-of-Charge (SoC)

It represents the remaining amount of the charge
in (0,1 or 0, 100%)
SoC and charging characteristic of a E-car with
Lead battery
 Influence on the charging
conditions

Aging condition

Charge-discharge current

Temperature

Measured capacity Cm
Qb   I  dt
t
SoC 
Cm  Qb
Cm
Difference between energy and increment of the
charge
Elektromobilität
9
Battery technique
State-of-health
 Aging of the battery
 Described using the state-of-health (SoH)
 Reduction of the capacity
 Increase of the internal resistances
 Increase of the self-discharge
 Reduction of the nominal voltage
SoH 
Cm
 100%
CN
Durability of a VRLA-Batterie, Quelle: CSB-Battery EVH12150
 State-of-health (SoH)
 Ratio between measured capacity and nominal
capacity
 Limit value 80% (60, 70% possible)
Quelle: www.cadex.com
 Limit value related to the end of the life time
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Elektromobilität
Battery technique
self-discharge
 Self-discharge
 Discharge losses depending on
time
 Dangerous for the cells
 Caused by
 Connected consumers(i.e. BMS)
 Nominal reactions
Tipical representation of self-discharge
 Internal short circuit
 Self-discharge affetcs:
 charging, discharging, pause
100
Kapazität [%]
80
60
40
Berechnung
3 Tage
28 Tage
20
0
0
5
10
QSR 
15
20
25
30
QS
 100%
t Lag  CN
Zeit [d]
Self-discharge of a LiFePO4- battery
Full charge
Pause time
Discharge
Rate of self-discharge
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Elektromobilität
Battery technique
internal resistance
 Internal resistance direct current
 Reduction terminal voltage. It depends on the
current
 It may cause increase of the temperature
 It depends on the SoC and the Temperature
50
Strom [A]
Strom
Spannung
20
40
10
0
30
0
2
4
6
8
Zeit [min]
Principle of DC-resistance identification
10
12
20
14
Spannung [V]
30
Gleichstromwiderstand [mOhm]
Equivalent circuit diagram of a battery
300
250
200
150
100
0
2
4
6
8
10
12
14
Zeit [min]
Calculated distribution of the DC-resistance of a LiFePO4-battery
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Elektromobilität
Battery technique
charging methods
Overview of charging methods
Source: Battery Technology Handbook
 IU-charging methods
 Charging at constant current
 After achieving the end of charge voltage it
charges at constant voltage
 Ending of charging according the current or
time criteria
 applications for lead, Li-Ion, Na/NiCl
Principles of the IU-Loading method Quelle: www.itwissen.info
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Elektromobilität
Battery technique
charging methods
 IUoU- Charging method
 as IU-charging, however the voltage in
the first phase can be higher
 After a specific time the voltage
decreases
 Short charging time is possible
 Application for lead, Li-Ion
Principles of the IUoU-Loading Method Quelle: www.itwissen.info
I-Load og a NiMH-Cell with ΔU-Cut-Off
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Elektromobilität
Battery technique
boost charging method
 Theory of boost charging
 High current. The charge
progressively decreases SoC
(progressively increases)
 The maximal current decreases with
the time
 The charging can be improved by
using negative current pulse
(Depolarization)
Tipical carge-times for boost-charges up to 80% SoC
Ultra-Fast DC-Charge Infrastructures for EV-Mobility and Future Smart Grids
 MCC-CV
 Negative current pulse
for the depolarization
Maximal Load-current over the time
MCC-CV-Boostcharging Method with negative
pulses
Research on Fast Charge Method for Lead-acid EV-Batteries
Elektromobilität
15
Battery technique
boost charging method
 Boost charging NiCd
 I-charging
 IUa-charging
 End after formation of
hydrogen
 Higher charging current
(I>1C)
 Increase of the
temperature reduces the
efficiency
 Charging time lower
than one hour
Potential-diagrams during a pulsecharge R. Groiß,
„Schnellladung und Pulsladung von Bleibatterien“
 Pulse method
 Special case of Icharging
 Variation Pulse/Pause
 Measurement of the
voltage during the
pause
IUa-boost-charge of a LiPo-battery with 3C Performance
Evaluation of Lithium Polymer Batteries for Use in Electric Vehicles
I-boostcharge of a NiCd-battery (6V, 100Ah)
Application Range of Fast-Charging in Ni-Cd Batteries
16
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Battery test technique
overview
 Battery testing :
 Different manufacturer´s data
 Determination of the capacity, temperature
performance, life time, …
 Modification of the batteries for the system
targets
t
Capacity: C
  I t   dt
o
Efficiency:  Ah 
QE
QL
 Standards für the applications and type of
batteries
Battery testing-station up to1000kW (1000A), Quelle: FuelCon
IEC Battery-testing-station, Quelle: Digitron
17
Elektromobilität
Battery test technique
overview
 Field of applications of battery test technique:
Test- Accuracy, Quelle: DIN IEC 61960
 Battery design (optimization)
 Battery producer ( quality, cell selection)
 Equipments design (choice, battery parameter)
 Equipement producer (control of quality)
 Service, operator (SoC, SoH…)
Parameter
accuracy
Voltage
±1%
Current
±1%
Capacity
±1%
Temperature
±2°C
time
±0,1%
Choice of standards for battery testing, Source: Jossen, Weydanz: „Moderne Akkumulatoren richtig einsetzen“
Application
Lead acid
NiCd-Battey
NiMH-Battery
Lithium-Ions Battery
Small traction
IEC 61982-2
BCI-Standard
IEC 60623
Keine Norm
Keine Norm
Traction
IEC 60254-1
AS 2402
IEC 60623
Keine Norm
Keine Norm
EV / HEV
IEC 61982
USABC
IEC 61982
USCAR/USABC
EUCAR
USCAR/USABC
EUCAR
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Elektromobilität
Battery test technique
life time test
 Life time test
 Reduction of the terminal voltage
 It depends on SoC, Temperature
Principle of testing durability
Cycletests for batteries, Quelle: C3 Prozess- und Analysetechnik GmbH
Test-accuracy, Quelle: DIN IEC 61960
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Elektromobilität
Battery test technique
Temperature
 Temperature has an influence on
 Self-discharge
 capacity
 Life time
 Conservation of the charged current
 degradation („thermal runaway“)
Temperature-increasement of a NiMH-hybrid vehicle battery
with a current of100A Quelle: Electro-Thermal Modeling to improve Battery design
 Temperature test
 Temperature chamber
 Infra red thermography
 DIN IEC 21/455/CD
Test-assembling with temperature-chamber
20
Elektromobilität
Batteries and Battery systems
Battery management system
 Battery management system (BMS)
 Controlling of the important safety
parameters (T, I, U)
 Cell balancing
 Estimation of the SoC
 Diagnostic functions and interfaces
Key-functions of a BMS,
Quelle: courtesy of Compact Power Inc.
 Other functions
 Load management
 History
 Autentication
Block diagram of a battery management system, Quelle Hochschule Bochum
21
Elektromobilität
Batteries and Battery systems
Battery management systems
 Cell balancing
 By seriall connection
 Same types cells may be different in
 Time perfomance
 capacity
 Self-discharge
≠
 Temperature performance
Loss of Capacity through un-balanced cells, Quelle: Intersil
Balancing of 3 LiFePO4-cells
22
Elektromobilität
Batteries and Battery systems
State of Charge
 State of charge (SoC)
 Estimation of remaining charge
 Consideration of current and temperature
 Based on the Ah-meter, open circuit
voltage or methods for modeling is
possible
Blockstructure of an Soc-module
 State of the Charge
 Information on the cruise range
 Information on remaining capacity
Compact SoC-module of an electric
vehicle
Elektromobilität
 Indirect information on remaining
charging time
23
Batteries and Battery systems
Heat management
 Heat management for batteries
 Observation of tolerable operation temperature
 Cooling during discharge
 Heating at low ambient temperature (high
temperature battery)
Heat transport from a battery, Battery
Technology Handbook 2008
Battery of PH Toyota Prius with
internal cooling system, Quelle: Autonews
Battery heating- and cooling
system of the Chevrolet Volt, Quelle:
//gm-volt.com
24
Elektromobilität
Batteries and Battery systems
Lead gel battery
Wirkleistung [kW]
 Maintenance free (VRLA) for traction
 Cell voltage: 2V but high weight
 Robust and high life time
 Low priced
100
1.5
Wirkleistung
State of Charge 75
1
50
0.5
25
0
0
2
4
6
State of Charge [%]
2
 Lead battery
0
10
8
Zeit [h]
AC-loadcharacteristics of the electric vehicle
MEGA e-City
Strom [A]
0
-100
-200
-300
Electric vehicle MEGA e-City and interconnection of the
transaction-battery
0
2
4
6
8
10
12
Zeit [min]
14
16
18
20
22
Measured speed profile and current intake of MEGA eCity during an extra urban trip
25
Elektromobilität
Batteries and Battery systems
Lead gel battery
 Operation
 Discharge as deep as necessary
 Before the charging no discharge
 Storing in full charged status
 Aeration needed (Hydrogen can be
produced)
Traction battery of the E-car SAM Quelle: cree
TWIKE
AC- charging characteristic of a Twike
DC-charging characteristic of SAM
26
Elektromobilität
Batteries and Battery systems
Lithium-Ions (Li-Ion)
 Lithium-Ions
 Cells voltage circa 3,7V
 Limited self-discharge
 High efficiency
Costs- and energy density trend of Li-Ions cells Quelle:
batteryuniversity.com
 Lithium
 Leight metal
 0,006% in der earth crust
 High reactiveness
27
Elektromobilität
Batteries and Battery systems
Lithium-Iones-Accumulator (Li-Ion)
 Li-Ion as a transaction battery
 In case of failure thermical energy 6 times
higher than electrical energy
 Prefered for traction because of high energy
density, freedom of maintenance and longlife-cycles
 Gasoline-car with consumption of 3-4l/100km
corrisponds a Li-Ions-loaded vehicle with
europ. current mix, Quelle: S. Voser, EMPA 2010
Li-Ion-Battery of E-Mini Quelle:
Li-Ion-cells for vehicle- applications,
flickR, BMW
Automedienportal.net/Bosch
Construction of a Li-Ion for Hybrid vehicles,
www.automobil-produktion.de
450kg storage-battery unit of Tesla
Roadstar, RW=365km, Kosten 13.300€,
Quelle: heise Autos
Elektromobilität
28
Batteries and Battery systems
Lithium-Polymer (LiPo)
 Lithium-Polymer-Accumulatores (LiPo)
 Seperator made of Polymer
 Very high specific energy-density
 Temperature-sensitive
 Sensitive against mechanical exposures
 Popular field: pattern-making
CCCV-Load of the cellblocks
 Electrical Characteristics
 Nominal voltage ca. 3,7V
Picture and construction of a transaction-battery on the base of LiPO-Cells
 for CCCV-load, decrease of endof-charge-voltage is
advantageous
29
Elektromobilität
Batteries and Battery systems
Lithium-Iron-Phosphate-Accumulator (LiFePO4)
 Lithium-Iron-Phosphate Battery (LiFEPO4)
 Electrical characteristics
 Comperatively a quite „young“
technology
 Nominal tension 3,3V
 Reversible 2-phase-reaction
(very plain potential curves)
 High thermal stability
 Excellent Aging-Characteristics
Strom [A]
40
100
30
75
20
50
10
Ladung [Ah]
LiFePO 4  Li  FePO4
 Good sicurity characteristics
25
Strom
Ladung
0
0
0.5
1
1.5
2
0
2.5
Zeit [h]
Construction of a LiFePO4-System for traction applications and CCCV-chargingcharacteristic
Elektromobilität
30
Batteries and Battery systems
Lithium-Iron-Phosphate-Accumulator (LiFePO4)
Limo-Green Hybrid
LiFePO4-Battery- system Quelle: aquawatt
LiFePO4-Battery- system from GAIA
Quelle: www.solar-sicherheit.de
LiFePO4-Accu (8,6kWh) behind the
back seats of the Jaguar Limo-Green,
Quelle: www.motorvision.de
Electrovehicle Stromos andcurrent profile during loading Stromverlauf
31
Elektromobilität
Batteries and Battery systems
Natrium-Nickel chloride-Accumulator (NaNiCl)
 Natrium-Nickel chloride (NaNiCl)
 Developed in the 1980s (ZEBRA – Zero Emission Battery
Research Activities)
 Battery at high temperature with a cell tension of 2,58V
 temperature range from 250 to 350°C (heating system)
 ZEBRA-complete system (Battery, BMS, battery charger)
 Ampere degree of efficiency of 100%
NaNiCl-accumulator
Quelle: A. Gillhuber, elektroniknet, 09
NaNiCl-accumulatores (ZEBRA) and demonstration of the principle of the battery system Quelle: Dustmann,C. H. “Advances in
ZEBRA batteries”
32
Elektromobilität
Batteries and Battery systems
Natrium-Nickel chloride-Accumulator (NaNiCl)
 Particularity of the ZEBRA-Battery
 1- and 3-phasic battery charger
possible
150
100
100
Temperatur
Spannung
0
4
8
300
1500
1000
Temperatur [°C]
Wirkleistung [W]
2000
16
20
24
Heating-cycle of a ZEBRA-Battery
 Body with thermical isolation
 With CAN the BMS can be read-out
(SoC, U, I, T)
12
Zeit [h]
Temperatur
Spannung
253,5V
3000
2500
200
300
208,6°C
200
200
100
100
500
0
0
2
4
6
8
10
Zeit [h]
Monophasic Load of a ZEBRA-Battery
0
12
Manufacturer´s suggested
battery charger, Quelle: MES-DEA
0
2
4
6
8
0
10
Zeit [d]
Termperature and voltage
characteristic during cooling-down
33
Elektromobilität
Spannung [V]
252V
200
Spannung [V]
 Co-current flow heating (selfdischarge)
300
211,5°C
Temperatur [°C]
 Monophasic alternating current
heating
250
Batteries and Battery systems
Natrium-Nickel chloride-Accumulator (NaNiCl)
Crash-Test with 50km/h (1)
Electric vehicles and hybrid vehicles with ZEBRA-Batteries(1)
(1) Dustmann,C. H. “Advances in ZEBRA batteries”
Self-discharge of a ZEBRA-Battery in parking-mode
34
Elektromobilität
Batteries and Battery systems
Nickel- Metal-hydride –Accumulator (NiMH)
 Nickel-Metal-hydride-Accu
 Advencement of the NiCd-Accu (no
memory-effect anymore)
 Cell voltage of 1,2V
 Relatively high weight
 Mainly used for hybrid vehicles
NiMH-Battery (6,5Ah, 288V) of the Toyota
Prius, Quelle: wapedia
Toyota Rav4-EV caruuu.com
NiMH-Batterypack of Rav4-EV
Quelle: www.techno-fandom.org
AC-load characteristics of the NiMH-Battery of
the Rav4-EV Quelle: Southern California Edison, datasheet, 1999
35
Elektromobilität
Batteries and Battery systems
Nickel- Metal-hydride –Accumulator (NiMH)
 Characteristics of NiMH-Accu
 Storable at every state of charge
 Properties are not inflammable
 Sensitive against overload,
overheating, deep discharge
Phileas Bus (Hybrid) and NiMH-Battery Quelle: G. Schädlich, Hoppecke, 2010
Load- and unload characteristics for the refreshcycle of a NiMHcell
Elektromobilität
Quelle: G. Schädlich, Hoppecke, 2010
36
Batteries and Battery systems
Future Trends
 Developmental potentials
 Cathodic materials
 Safety tecnologies
 Durability
 System of Battery management
 Cost reduction within the mass production
 Start-Stop technology for hybrid and electro
vehicles
Higher nergy densities with new zinc-air-cells
for electric vehicles Quelle: ReVolt
 Application of Nano technologies
 Enlargement of electrode surface
 Optimization of iontransport
Objective for the consumer batteries
costs less
37
Elektromobilität
Thanks for your attention!
Quelle: www.zazzle.de
38
Elektromobilität
Einleitung
Geschichte des Akkumulators
 Die „Bagdad-Batterie“

Ca. 100 v. Chr.

15 cm hohes Tongefäß

Kupferzylinder gefüllt mit Essiglösung

0,5V zwischen Eisenstab und Zylinder
Nachbidung der „Bagdad-Batterie“
Quelle: w³.praschensky.com
 Galvanische Elemente

1780 durch Luigi Galvani entdeckt

Grundlage für elektrochem. Zellen
 Die Voltasche Säule
Nachbidung einer
Voltasäule Quelle: Luigi Chiesa
Galvani‘s Experiment, Quelle: w³.life.com

1799 durch Alessandro Volta entwickelt

Geschichtete Kupfer(Silber)-Zink(Zinn)plättchen

Salzsäure getränktes Papier (Leder) als Separator
39
Elektromobilität