PCCM for Peak Thermal Load Shaving of LIB During 6C Fast Charge
Lithium-Ion Secondary Batteries (LIB) have a narrow operational window in terms of cell temperature. The optimum working temperature is between 15 and 45°C. Thus, modern battery systems for electric vehicles have complex active thermal management systems allowing for heating and cooling to operate the LIB in its desired temperature range. These systems often need to […]
State of Health Estimation of Lithium-Ion Batteries under Real-World Operational Conditions
Due to the transition to electric mobility the interest for the battery as core component of every battery electric vehicle (BEV) and its State of Health (SOH) rises. Multiple supervised machine learning methods have been applied to the regression task of SOH estimation of lithium-ion batteries from the charging curve under laboratory operational conditions [1–6]. […]
Parametrization & time-domain transformation of discrete transmission line models for graphite electrodes
Transmission line model (TLM) or mixed conducting networks are used frequently for the characterization of porous electrodes based on the electrodes’ impedance data, showing the influence of the porous morphology and of spatially distributed behavior in the frequency domain. For this purpose, transfer functions are used to characterize the TLM, representing the overall polarization behavior […]
Dilatometry relaxation as a detection method for reversible lithium deposition in lithium-ion batteries
Fast-charging of lithium-ion batteries at low temperatures and high states of charge (SOC) can lead to accelerated ageing. The primary mechanism that causes the loss of cyclable lithium inventory under those conditions is the irreversible deposition of metallic lithium on the surface of the graphitic anode. The more significant share of the metallic lithium is […]
Measurement of the Frequency Dependent Acoustical Transmission for the Characterisation of Mechanical Changes in Lithium-Ion Cells
The poster describes the performed steps in order to develop a reproducible ultrasonic-based diagnosis method for lithium-ion cells. In order to assess how useful this method can be several measurements where performed to answer the following questions: How easily can variations in temperature or the sensor coupling affect the results? Secondly, what are typical statistical […]
Development of an online State-of-Health estimation method for lithium-ion batteries, based on bus fleet data
This study contributes to the development of an online-capable estimation method for State of Health (SoH) estimation for Li-Ion batteries. Implemented on the battery control unit, it is possible to register the aging based on four state variables. These variables include the state of charge (SoC), depth of discharge (DoD), voltages, temperatures, and current rates […]
Electrochemical modeling, validation and parameter identification under high current discharge conditions for a commercial Li-ion battery.
Extreme scenarios of high discharge current must be understood for better battery management system design. Physics-based modeling can give a better insight into the battery response compared to equivalent circuit models but can be challenging due to the large number of parameters. In this work, an electrochemical pseudo-2D model is developed and used in the […]
A new method for the mechanical characterization of automotive lithium-ion pouch cells
Large-format pouch cells are widely used in the automotive industry and stacked in modules to increase energy density on battery level. Since pouch cells are packaged in a flexible foil (pouch bag) a mechanically stable module design is crucial for battery safety and optimum lifetime [1]. Design of such requires information about the mechanical properties […]