Replication of the thermal behaviour of lithium-ion cells with substitute cells
The performance as well as the lifetime of lithium-ion battery cells are strongly temperature-dependent. To achieve optimal results in both aspects, efficient thermal management systems are needed in the automotive application. Along the development process of these systems, manufacturers face certain obstacles considering the validation of battery systems. An extensive experimental infrastructure is required and […]
Data compression techniques applied to long-term recordings of battery data from electric vehicles
Data compression offers the possibility to decrease the amount of storage or the bandwidth of a communication channel required to save or transmit collected data. In battery packs of electric vehicles (EV), the data over time contains values of voltage, current, temperature, state of charge and others depending on the battery management feasibility. Compression of […]
Impact of Level of Homogenization in 3D Thermal Simulation of Li-ion battery cells [1]
Temperature has a large impact on the performance and aging behavior of Li-ion batteries. Therefore, the temperature range for optimal performance and minimum aging of Li-ion batteries should be ensured during operation. The knowledge of the internal temperature field in Li-ion batteries is essential in this respect. Since in-situ measurements of the internal temperature distribution […]
Equivalent circuit model of a 180 Ah LFP/graphite home storage cell for model-based state diagnostics
State of Charge (SOC) and State of Health (SOH) are important parameters for the users and manufacturers of home storage systems. The state diagnostics of LFP/graphite cells is challenging due to the inherent thermodynamic hysteresis and the flat, but unsymmetrical discharge/charge characteristics. Battery models allow a knowledge-based and therefore more reliable state diagnostics. We present […]
Li-ion batteries studied with Scanning Electron Microscopy and combined analytical methods
The complex interaction in batteries is most clearly visible at the interfaces between anode, cathode, separator and electrolyte. A post-mortem microstructural examination of changes on the surfaces of the anode, cathode and separator offers great potential on the way to understand the complex interaction in batteries during ageing. The combination of scanning electron microscopy (SEM) […]
Optimal power split for heterogeneous storage systems – A comparative study of model predictive control and dynamic programming
Li-ion batteries are commonly used in stationary and mobile energy systems, and its markets are growing rapidly. Due to the high impact of energy costs on the economics and life cycle assessment, the efficiency of storing electrical energy becomes one of the main points of interest. This can be reached by improving the general efficiency […]
Influence of (meta-)parameters on the behavior of state of charge estimation using an extended Kalman Filter
State estimation is a core function of any battery management system (BMS) in order to ensure safe operating conditions and to prolong the lifetime of the energy storage system. In this context the state of charge (SOC) is an important indicator for the remaining useable battery capacity. This variable is not a measurable value, but […]
Experimental validation of Parallel-Connected Lithium-Ion Cells with Controllable Interconnection Resistance
Due to the broad use of parallel-connected cells across multiple applications, it is essential to understand the current distribution between them. Variations in resistance, temperature and capacity can lead to an inhomogeneous current distribution and have a deleterious influence on ageing and safety. It is therefore crucial to investigate the current distribution within such systems. […]
A Comparison of Different Methods for Physically Motivated Parameterization of High Power Lithium-Ion Battery Cells
The development of lithium-ion batteries with high power density is currently being driven by their potential applications in mild hybrid vehicles. A 48 V electrical system in passenger cars can provide an efficiency advantage and reduce CO_2 emissions by about 10 % to 15 %. Pouch bag cells having a lithium-titanate (Li_4Ti_5O_12) anode and a […]
A Comparison of Different Methods for Physically Motivated Parameterization of High Power Lithium-Ion Battery Cells
The development of lithium-ion batteries with high power density is currently being driven by their potential applications in mild hybrid vehicles. A 48 V electrical system in passenger cars can provide an efficiency advantage and reduce CO_2 emissions by about 10 % to 15 %. Pouch bag cells having a lithium-titanate (Li_4Ti_5O_12) anode and a […]