2. Aging of Lithium Ion Batteries
Dr. Falko Schappacher
MEET Battery Research Center, University of Münster, Germany
September 28th, 2017, Powering Mobility, Enschede, Netherlands

3. Battery-Performance: The wish list is comprehensive
Cost (Competitiveness, Economy, Product Acceptance)
Energy (Range, Operating Time)
Power (Performance, Dynamics)
Safety (Failure, Abuse, Maintenance, Accident)
Lifetime (Cycles, Immobilization Time)

4. Lithium Ion Battery Mode of Operation
Charge
Discharge
Anode
SEI
Cathode
Separator
Electrolyte

5. There is no „The Lithium Ion Battery“

6. Aging
Young
Middle-Aged
Aged

7. Aging: „Power Fade“ and „Capacity Fade“U I
Concentration
Polarization
IR Drop
Open Circuit Voltage U0 (OCV)
Activation
Young
Middle-Aged
Aged P I
min. Power
Young
Middle-Aged
Aged
Cycle life / Calendar life
Capacity
Initial capacity = C0
Residual
capacity
= Cm
(measured
capacity)
Capacity loss
State of Health: SoH = Cm / C01)

8. Battery Aging: Electrochemical, Mechanical, Thermal
Cycle Life
Calendar Life
Full Cycles
Charge, Discharge, Overcharge
Load Profile
Temperature
State-of-Charge (SOC)
Temperature
 Self Discharge

9. Lifetime of Lithium Ion Batteries: Why is the lifetime limited?
Wasteage: „Nothing lasts forever":
LIB-Materials „breath“ on intercalation and de- intercalation of Li  mechanical stability of the active material and the electrode decreases (esp. fully charged respectively fully discharged state)
Swelling of electrodes/separators with electolyte
Contamination causes corrosion, damages sealings, housing, current collectors, et cetera
2) Electrochemical reactivity ( high cell voltage)
Highly reductive conditions at the anode
Highly oxidative conditions at the cathode
In both cases:  High reactivity of electrodes and electrolyte:  electrolyte decomposition  gasing and formation of interphases  corrosion of the electrodes

10. Lithium Ion Battery Aging: Anode

11. Lithium Ion Battery Aging: Cathode

12. Lithium Ion Battery Aging What are the Influencing Factors?

13. Lithium Ion Battery Aging Cycling at Different Temperatures
18650-type cell
Samsung, 2,2Ah

14. Lithium Ion Battery Aging Influence of Charge/Discharge-Rate

15. Lithium Ion Battery Aging Influence of Loadprofile and Temperature

16. Conclusion There is no “the Lithium Ion Battery”
Lithium Ion Batteries are designed for special applications
Lithium Ion Battery Aging can be categorized into “cyclic” and “calendric” aging
Several aging mechanisms take place at all components of a LIB at the same time
Charge/Discharge rate and temperature have major influence on the aging
Even at the limits of the specification modern LIB “live” for hundreds of thousands of kilometers

17. Aknowledgement Prof. Dr. Martin Winter Team „Cell System“
Markus Börner, Alex Friesen, Jan Haetge, Debbie Berghus
Team „Analytics and Environment“
MEET Team
Federal Ministry of Education and Research (BMBF) for funding of the project „SafeBatt“ (FKZ: 03X4631N)