@article{KomsiyskaBuchbergerDiehletal.2021, author = {Komsiyska, Lidiya and Buchberger, Tobias and Diehl, Simon and Ehrensberger, Moritz and Hanzl, Christian and Hartmann, Christoph and H{\"o}lzle, Markus and Kleiner, Jan and Lewerenz, Meinert and Liebhart, Bernhard and Schmid, Michael and Schneider, Dominik and Speer, Sascha and St{\"o}ttner, Julia and Terbrack, Christoph and Hinterberger, Michael and Endisch, Christian}, title = {Critical review of intelligent battery systems}, volume = {14}, pages = {5989}, journal = {Energies}, subtitle = {challenges, implementation, and potential for electric vehicles}, number = {18}, publisher = {MDPI}, address = {Basel}, issn = {1996-1073}, doi = {https://doi.org/10.3390/en14185989}, year = {2021}, abstract = {This review provides an overview of new strategies to address the current challenges of automotive battery systems: Intelligent Battery Systems. They have the potential to make battery systems more performant and future-proof for coming generations of electric vehicles. The essential features of Intelligent Battery Systems are the accurate and robust determination of cell individual states and the ability to control the current of each cell by reconfiguration. They enable high-level functions like fault diagnostics, multi-objective balancing strategies, multilevel inverters, and hybrid energy storage systems. State of the art and recent advances in these topics are compiled and critically discussed in this article. A comprising, critical discussion of the implementation aspects of Intelligent Battery Systems complements the review. We touch on sensing, battery topologies and management, switching elements, communication architecture, and impact on the single-cell. This review contributes to transferring the best technologies from research to product development.}, language = {en} } @article{StoettnerHanzlTerbracketal.2025, author = {St{\"o}ttner, Julia and Hanzl, Christian and Terbrack, Christoph and Endisch, Christian}, title = {Holistic evaluation and optimization of multilevel inverter designs for electric vehicle applications}, volume = {2025}, journal = {Energy Reports}, number = {13}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2352-4847}, doi = {https://doi.org/10.1016/j.egyr.2025.03.001}, pages = {3561 -- 3573}, year = {2025}, abstract = {To advance the development of multilevel inverters (MLIs) for electric vehicle applications, this study introduces novel asymmetric MLI (AMLI) configurations featuring buffer modules to enhance efficiency. A comprehensive comparative analysis of 125 distinct inverter systems is conducted, integrating five different microtopologies and 25 representative symmetrical MLI (SMLI) and AMLI systems. Unlike previous studies, this work employs a successive design process with a graph-based approach to systematically minimize conduction losses. Furthermore, experimental loss measurements ensure practical relevance. By applying Pareto optimization with cost, energy losses, and total harmonic distortion as objective functions, the study identifies the most promising MLI systems among all considered ones. While the cascaded H-bridge MLI emerges as the most cost-effective solution, specific SMLI configurations with 12 or 18 battery cells per module and AMLI designs featuring buffer modules exhibit lower inverter losses. In both cases, the incorporation of microtopologies that enable parallel operation leads to a remarkable reduction in inverter losses by more than 30 \% compared to the least efficient MLI systems. Finally, a comparative assessment against a conventional B6-bridge SiC inverter highlights the significant advantages of these optimized MLI configurations in terms of efficiency and system performance.}, language = {en} } @inproceedings{KleinerHeiderHanzletal.2020, author = {Kleiner, Jan and Heider, Alexander and Hanzl, Christian and Komsiyska, Lidiya and Elger, Gordon and Endisch, Christian}, title = {Thermal behavior of an intelligent li-ion cell under vehicle conditions}, booktitle = {Proceedings: IECON 2020 The 46th Annual Conference of the IEEE Industrial Electronics Society}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-5414-5}, issn = {2577-1647}, doi = {https://doi.org/10.1109/IECON43393.2020.9254336}, pages = {2081 -- 2086}, year = {2020}, language = {en} } @article{SchmidGebauerHanzletal.2020, author = {Schmid, Michael and Gebauer, Emanuel and Hanzl, Christian and Endisch, Christian}, title = {Active model-based fault diagnosis in reconfigurable battery systems}, volume = {36}, journal = {IEEE Transactions on Power Electronics}, number = {3}, publisher = {IEEE}, address = {Piscataway}, issn = {1941-0107}, doi = {https://doi.org/10.1109/TPEL.2020.3012964}, pages = {2584 -- 2597}, year = {2020}, language = {en} } @article{HanzlHartmannHoelzleetal.2021, author = {Hanzl, Christian and Hartmann, Christoph and H{\"o}lzle, Markus and Liebhart, Bernhard and Schmid, Michael and Endisch, Christian}, title = {Current commutation in a switched lithium-ion cell used in cascaded half-bridge multilevel inverters}, volume = {14}, journal = {IET Power Electronics}, number = {6}, publisher = {Wiley}, address = {Hoboken}, issn = {1755-4543}, doi = {https://doi.org/10.1049/pel2.12088}, pages = {1073 -- 1088}, year = {2021}, abstract = {In order to improve the efficiency of battery electric vehicles, the utilization of reconfigurable batteries and multilevel inverters based on low-voltage Si MOSFETs gains growing attention. Focusing on the half-bridge as basic switching unit, this paper examines voltage and current waveforms during switching. It is shown that the current commutation speed depends on various factors such as sign and amplitude of the current as well as the particular switching scenario. For instance, turning off a positive cell current takes 0.21 𝜇s while turning it on takes 0.9 𝜇s. In addition, it is revealed that depending on the switching scenario and current direction, the lithium-ion cell supports or opposes the remagnetization of the parasitic inductances and therefore the switching losses of the MOSFETs. Switching a positive load current of 125 A from active to bypass converts 276 𝜇J into heat while switching from bypass to active converts merely 32.5 𝜇J into heat.}, language = {en} } @inproceedings{MayerArnetGankinetal.2019, author = {Mayer, Sebastian and Arnet, Christian and Gankin, Dennis and Endisch, Christian}, title = {Standardized framework for evaluating centralized and decentralized control systems in modular assembly systems}, booktitle = {2019 IEEE International Conference on Systems, Man and Cybernetics (SMC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-4569-3}, doi = {https://doi.org/10.1109/SMC.2019.8914314}, pages = {113 -- 119}, year = {2019}, language = {en} } @inproceedings{MayerGankinArnetetal.2019, author = {Mayer, Sebastian and Gankin, Dennis and Arnet, Christian and Endisch, Christian}, title = {Adaptive production control with negotiating agents in modular assembly systems}, booktitle = {2019 IEEE International Conference on Systems, Man and Cybernetics (SMC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-4569-3}, doi = {https://doi.org/10.1109/SMC.2019.8914498}, pages = {120 -- 127}, year = {2019}, language = {en} } @inproceedings{GerngrossHerrmannWestermaieretal.2017, author = {Gerngroß, Martin and Herrmann, Patrick and Westermaier, Christian and Endisch, Christian}, title = {Highly flexible needle winding kinematics for traction stators based on a standard industrial robot}, booktitle = {2017 7th International Electric Drives Production Conference (EDPC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-5386-1069-5}, doi = {https://doi.org/10.1109/EDPC.2017.8328147}, year = {2017}, language = {en} } @inproceedings{GerngrossHerrmannEndischetal.2019, author = {Gerngroß, Martin and Herrmann, Patrick and Endisch, Christian and Westermaier, Christian}, title = {Optimization of the End Winding Patterns in Needle Wound Traction Stators}, booktitle = {Proceedings, 2019 IEEE International Conference on Mechatronics (ICM)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-5386-6959-4}, doi = {https://doi.org/10.1109/ICMECH.2019.8722897}, pages = {314 -- 320}, year = {2019}, language = {en} } @article{StoettnerHanzlEndisch2023, author = {St{\"o}ttner, Julia and Hanzl, Christian and Endisch, Christian}, title = {Experimental investigation of parasitic side effects in MOSFET-based multilevel inverter for electric vehicle applications}, volume = {2023}, pages = {109197}, journal = {Electric Power Systems Research}, number = {218}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-2046}, doi = {https://doi.org/10.1016/j.epsr.2023.109197}, year = {2023}, language = {en} } @article{WilliamsNgaleuTheilerStrasseretal.2022, author = {Williams Ngaleu, Guy and Theiler, Michael and Straßer, Xenia and Hanzl, Christian and Komsiyska, Lidiya and Endisch, Christian and Lewerenz, Meinert}, title = {Influence of Switching on the Aging of High Power Lithium-Ion Cells}, volume = {8}, pages = {33}, journal = {Batteries}, number = {4}, publisher = {MDPI}, address = {Basel}, issn = {2313-0105}, doi = {https://doi.org/10.3390/batteries8040033}, year = {2022}, abstract = {For intelligent battery systems that are able to control the current flow for each individual cell, the multilevel inverter is an interesting approach to replace the bidirectional AC/DC-converter and improve flexibility of charging system and signal quality in both directions. Therefore, the cells are modulated by switching varying the duty cycle, the current and the frequency up to the kHz-range. This is only beneficial if the switching does not lead to a significant additional aging. The scientific gap to assess and understand the impact of switching is investigated in this paper by testing 22 high-power 18650 lithium-ion cells (Samsung 25R). The cells are tested at 50 Hz and 10 kHz switching frequency during charge, discharge and charge/discharge at 50\% duty cycle. The tests are compared to eight reference tests with continuous current flow performed at the average and the maximum current for charge and discharge, respectively. The results are obtained by evaluating the remaining capacity, resistance, electrochemical impedance spectroscopy and dV/dQ analysis. Before reaching rollover, the investigated cells lose homogeneity and cathode capacity but no significant difference for the aging parameters are found. After rollover, the cell-to-cell variation is greater than the aging induced by the different cycling parameters.}, language = {en} } @inproceedings{HanzlStoettnerHoelzleetal.2023, author = {Hanzl, Christian and St{\"o}ttner, Julia and H{\"o}lzle, Markus and Endisch, Christian}, title = {Experimental Investigation and Analytical Modeling of Half-Bridge Switching Losses in Reconfigurable Lithium-Ion Cells}, booktitle = {ICPE 2023 - ECCE Asia: 11th International Conference on Power Electronics - ECCE Asia}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-89-5708-350-5}, doi = {https://doi.org/10.23919/ICPE2023-ECCEAsia54778.2023.10213901}, pages = {1058 -- 1065}, year = {2023}, language = {en} } @inproceedings{KohlerHerreraGerngrossetal.2024, author = {Kohler, Markus and Herrera, Christian and Gerngroß, Martin and Kennel, Ralph and Endisch, Christian}, title = {Empirical Investigation and Feed-Forward Control of Wire Tension in Needle Winding Processes}, booktitle = {2024 IEEE 33rd International Symposium on Industrial Electronics (ISIE), Proceedings}, publisher = {IEEE}, address = {Piscataway}, isbn = {979-8-3503-9408-5}, doi = {https://doi.org/10.1109/ISIE54533.2024.10595747}, year = {2024}, language = {en} } @article{StrasserWilliamsNgaleuHanzletal.2023, author = {Straßer, Xenia and Williams Ngaleu, Guy and Hanzl, Christian and Azzam, Mohamed and Endisch, Christian and Lewerenz, Meinert}, title = {Influence of Switching on the Aging of High Energy Lithium-Ion Cells}, volume = {9}, pages = {139}, journal = {Batteries}, number = {2}, publisher = {MDPI}, address = {Basel}, issn = {2313-0105}, doi = {https://doi.org/10.3390/batteries9020139}, year = {2023}, abstract = {An AC-battery or multilevel inverter used to increase safety and flexibility is realizable by switching the cells and modules on and off in a defined way and thus can replace the bidirectional converter. Assessing possible additional aging due to switching, the results of a previous study for a high-power optimized cell showed no influence on the current rates or the switching. In this paper, a highly energy-optimized LG 18650-cell is investigated to discuss the influence of switching during the charge and discharge process, respectively, as well as combining both processes together with clear performance differences when applying higher charge and discharge currents. Moreover, the influence of switching is discussed for the two frequencies (50 Hz and 10 kHz) and different duty cycles. The aging is analyzed by capacity loss and resistance increase, by dV/dQ analysis, and by electrochemical impedance spectroscopy. We found no clear negative influence of switching but a positive effect if the cells are switched during charge. The best performance is found for switching during charge as well as during discharge. The cell aging during switching is clearly determined by the average and not the maximum current applied. This work shows no negative effects of multilevel inverter applications on the tested cells.}, language = {en} } @inproceedings{HanzlEndisch2026, author = {Hanzl, Christian and Endisch, Christian}, title = {Closed-Form Modeling of MOSFET Switching Losses Including Variable Gate-Drain Capacitance and Zero-Voltage Switching}, booktitle = {Proceedings of the 2025 IEEE Transportation Electrification Conference and Expo, Asia-Pacific (ITEC Asia-Pacific)}, publisher = {IEEE}, address = {Piscataway}, isbn = {979-8-3315-5984-7}, doi = {https://doi.org/10.1109/ITECAsia-Pacific63742.2025.11345027}, year = {2026}, language = {en} } @article{StoettnerHanzlEndisch2022, author = {St{\"o}ttner, Julia and Hanzl, Christian and Endisch, Christian}, title = {Extensive investigation of symmetrical and asymmetrical cascaded multilevel inverters for electric vehicle applications}, volume = {2022}, pages = {108009}, journal = {Electric Power Systems Research}, number = {209}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-2046}, doi = {https://doi.org/10.1016/j.epsr.2022.108009}, year = {2022}, language = {en} } @article{SchwertnerBuchbergerDiehletal.2025, author = {Schwertner, Stefan and Buchberger, Tobias and Diehl, Simon and Ferg, Rebekka and Hanzl, Christian and Hartmann, Christoph and H{\"o}lzle, Markus and Kleiner, Jan and Komsiyska, Lidiya and Lewerenz, Meinert and Liebhart, Bernhard and Schmid, Michael and Schneider, Dominik and Scholz, Florian and Speer, Sascha and St{\"o}ttner, Julia and Terbrack, Christoph and Hinterberger, Michael and Endisch, Christian}, title = {Design and Implementation of an Intelligent Reconfigurable High-Voltage Battery System for Next-Generation Electric Vehicles}, volume = {11}, pages = {11110424}, journal = {Batteries}, number = {11}, publisher = {MDPI}, address = {Basel}, issn = {2313-0105}, doi = {https://doi.org/10.3390/batteries11110424}, year = {2025}, abstract = {Battery system engineers face the challenge of balancing competing requirements regarding performance, maintainability, sustainability, safety, and cost—especially in the automotive industry. IBS potentially offer a solution with fewer trade-offs. They feature a battery management system with advanced sensing and data analysis capabilities that facilitate improved battery monitoring and operation. Reconfigurable energy storage units enable sophisticated operating strategies, including complete cell state control, full energy content utilization, and a measured response to faults. This article presents the design, development, and operation of a full-scale intelligent battery system prototype comprising 324 automotive lithium-ion cells with a nominal voltage of 400V. The system exhibits a modular single cell architecture and an advanced centralized battery management system. We detail the system architecture, hardware and software component design, and system integration. Initial tests demonstrate the battery's operability, extended functionality, and enhanced safety. Our analysis shows that the additional losses introduced by reconfigurability are more than offset by the benefits of full energy utilization—even for new cells, with increasing advantage as aging progresses. The results underscore the potential of intelligent battery systems and motivate further research and development toward economic assessment and industrial adoption.}, language = {en} } @article{KleinerKomsiyskaElgeretal.2019, author = {Kleiner, Jan and Komsiyska, Lidiya and Elger, Gordon and Endisch, Christian}, title = {Thermal modelling of a prismatic lithium-ion cell in a battery electric vehicle environment}, volume = {13}, pages = {62}, journal = {Energies}, subtitle = {influences of the experimental validation setup}, number = {1}, publisher = {MDPI}, address = {Basel}, issn = {1996-1073}, doi = {https://doi.org/10.3390/en13010062}, year = {2019}, abstract = {In electric vehicles with lithium-ion battery systems, the temperature of the battery cells has a great impact on performance, safety, and lifetime. Therefore, developing thermal models of lithium-ion batteries to predict and investigate the temperature development and its impact is crucial. Commonly, models are validated with experimental data to ensure correct model behaviour. However, influences of experimental setups or comprehensive validation concepts are often not considered, especially for the use case of prismatic cells in a battery electric vehicle. In this work, a 3D electro-thermal model is developed and experimentally validated to predict the cell's temperature behaviour for a single prismatic cell under battery electric vehicle (BEV) boundary conditions. One focus is on the development of a single cell's experimental setup and the investigation of the commonly neglected influences of an experimental setup on the cell's thermal behaviour. Furthermore, a detailed validation is performed for the laboratory BEV scenario for spatially resolved temperatures and heat generation. For validation, static and dynamic loads are considered as well as the detected experimental influences. The validated model is used to predict the temperature within the cell in the BEV application for constant current and Worldwide harmonized Light vehicles Test Procedure (WLTP) load profile.}, language = {en} } @article{ErikssonThomassonEkbergetal.2018, author = {Eriksson, Lars and Thomasson, Andreas and Ekberg, Kristoffer and Reig, Alberto and Eifert, Mark and Donatantonio, Fabrizio and D'Amato, Antonio and Arsie, Ivan and Pianese, Cesare and Otta, Pavel and Held, Manne and V{\"o}gele, Ulrich and Endisch, Christian}, title = {Look-ahead controls of heavy duty trucks on open roads — six benchmark solutions}, volume = {2019}, journal = {Control Engineering Practice}, number = {83}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-6939}, doi = {https://doi.org/10.1016/j.conengprac.2018.10.014}, pages = {45 -- 66}, year = {2018}, language = {en} } @article{LiebhartSatzkeKomsiyskaetal.2020, author = {Liebhart, Bernhard and Satzke, Martin and Komsiyska, Lidiya and Endisch, Christian}, title = {Application of nonlinear impedance spectroscopy for the diagnosis of lithium-ion battery cells under various operating conditions}, volume = {2020}, pages = {228673}, journal = {Journal of Power Sources}, number = {480}, publisher = {Elsevier}, address = {New York}, issn = {1873-2755}, doi = {https://doi.org/10.1016/j.jpowsour.2020.228673}, year = {2020}, language = {en} } @article{LiebhartKomsiyskaEndisch2019, author = {Liebhart, Bernhard and Komsiyska, Lidiya and Endisch, Christian}, title = {Passive impedance spectroscopy for monitoring lithium-ion battery cells during vehicle operation}, volume = {2020}, pages = {227297}, journal = {Journal of Power Sources}, number = {449}, publisher = {Elsevier}, address = {New York}, issn = {1873-2755}, doi = {https://doi.org/10.1016/j.jpowsour.2019.227297}, year = {2019}, language = {en} } @article{SchneiderVoegeleEndisch2019, author = {Schneider, Dominik and V{\"o}gele, Ulrich and Endisch, Christian}, title = {Model-based sensor data fusion of quasi-redundant voltage and current measurements in a lithium-ion battery module}, volume = {2019}, pages = {227156}, journal = {Journal of Power Sources}, number = {440}, publisher = {Elsevier}, address = {New York}, issn = {1873-2755}, doi = {https://doi.org/10.1016/j.jpowsour.2019.227156}, year = {2019}, language = {en} } @article{KleinerStuckenbergerKomsiyskaetal.2021, author = {Kleiner, Jan and Stuckenberger, Magdalena and Komsiyska, Lidiya and Endisch, Christian}, title = {Advanced monitoring and prediction of the thermal state of intelligent battery cells in electric vehicles by physics-based and data-driven modeling}, volume = {7}, pages = {31}, journal = {Batteries}, number = {2}, publisher = {MDPI}, address = {Basel}, issn = {2313-0105}, doi = {https://doi.org/10.3390/batteries7020031}, year = {2021}, abstract = {Novel intelligent battery systems are gaining importance with functional hardware on the cell level. Cell-level hardware allows for advanced battery state monitoring and thermal management, but also leads to additional thermal interactions. In this work, an electro-thermal framework for the modeling of these novel intelligent battery cells is provided. Thereby, a lumped thermal model, as well as a novel neural network, are implemented in the framework as thermal submodels. For the first time, a direct comparison of a physics-based and a data-driven thermal battery model is performed in the same framework. The models are compared in terms of temperature estimation with regard to accuracy. Both models are very well suited to represent the thermal behavior in novel intelligent battery cells. In terms of accuracy and computation time, however, the data-driven neural network approach with a Nonlinear AutoregRessive network with eXogeneous input (NARX) shows slight advantages. Finally, novel applications of temperature prediction in battery electric vehicles are presented and the applicability of the models is illustrated. Thereby, the conventional prediction of the state of power is extended by simultaneous temperature prediction. Additionally, temperature forecasting is used for pre-conditioning by advanced cooling system regulation to enable energy efficiency and fast charging.}, language = {en} } @article{TheilerEndischLewerenz2021, author = {Theiler, Michael and Endisch, Christian and Lewerenz, Meinert}, title = {Float Current Analysis for Fast Calendar Aging Assessment of 18650 Li(NiCoAl)O2/Graphite Cells}, volume = {7}, pages = {22}, journal = {Batteries}, number = {2}, publisher = {MDPI}, address = {Basel}, issn = {2313-0105}, doi = {https://doi.org/10.3390/batteries7020022}, year = {2021}, abstract = {Float currents are steady-state self-discharge currents after a transient phase—caused by anode overhang, polarization, etc.—is accomplished. The float current is measured in this study with a standard test bench for five 18650 cells (Samsung 25R) at potentiostatic conditions while the temperature is changed in 5 K steps from 5 °C to 60 °C. The entire test is performed in about 100 days resulting in 12 measurement points per cell potential for an Arrhenius representation. The float current follows the Arrhenius law with an activation energy of about 60 kJ/mol. The capacity loss measured at reference condition shows a high correlation to the results of float currents analysis. In contrast to classical calendar aging tests, the performed float current analysis enables determining the aging rate with high precision down to at least 10 °C. Returning from higher temperatures to 30 °C reference temperature shows reducing float currents at 30 °C for increasing temperature steps that may originate from an hysteresis effect that has to be investigated in future publications.}, language = {en} } @article{MayerClassenEndisch2021, author = {Mayer, Sebastian and Classen, Tobias and Endisch, Christian}, title = {Modular production control using deep reinforcement learning: proximal policy optimization}, volume = {32}, journal = {Journal of Intelligent Manufacturing}, number = {8}, publisher = {Springer Nature}, address = {Cham}, issn = {1572-8145}, doi = {https://doi.org/10.1007/s10845-021-01778-z}, pages = {2335 -- 2351}, year = {2021}, abstract = {EU regulations on CO2 limits and the trend of individualization are pushing the automotive industry towards greater flexibility and robustness in production. One approach to address these challenges is modular production, where workstations are decoupled by automated guided vehicles, requiring new control concepts. Modular production control aims at throughput-optimal coordination of products, workstations, and vehicles. For this np-hard problem, conventional control approaches lack in computing efficiency, do not find optimal solutions, or are not generalizable. In contrast, Deep Reinforcement Learning offers powerful and generalizable algorithms, able to deal with varying environments and high complexity. One of these algorithms is Proximal Policy Optimization, which is used in this article to address modular production control. Experiments in several modular production control settings demonstrate stable, reliable, optimal, and generalizable learning behavior. The agent successfully adapts its strategies with respect to the given problem configuration. We explain how to get to this learning behavior, especially focusing on the agent's action, state, and reward design.}, language = {en} } @article{MoralesTorricosBergFiggemeieretal.2025, author = {Morales Torricos, Pablo and Berg, Sascha and Figgemeier, Egbert and Endisch, Christian and Lewerenz, Meinert}, title = {The important role of lithiation-induced pressure change on apparent aging of lithium-ion batteries during accelerated cyclic aging tests}, volume = {2025}, pages = {117323}, journal = {Journal of Energy Storage}, number = {131, Part A}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2352-1538}, doi = {https://doi.org/10.1016/j.est.2025.117323}, year = {2025}, abstract = {In assessing the lifespan of lithium-ion batteries in laboratory conditions, the measured capacity declines during accelerated cyclic aging tests but increases when the cells are left idle. This recoverable capacity loss, known in literature as apparent aging, results from an inhomogeneous lithium distribution in the anode appearing in dV/dQ and capacity difference analysis. This study explores the origin of the apparent aging by correlating lithium distribution in the anode and recoverable capacity loss, with the lithiation induced pressure change and generated electrolyte motion during cycling. To this end, we compressed five commercial pouch lithium-ion cells (NMC/Gr) with holder stiffnesses ranging from 0.9 to 15.4 MPa/mm and offset pressure from 289 to 681 kPa and subjected them to continuous cyclic aging tests. While offset pressure had no significant impact, we observed, that holder stiffnesses over 3.3 MPa/mm induces an apparent capacity loss, which is recoverable by 35 \% during a resting phase. The root cause is the so-called electrolyte motion induced salt inhomogeneity (EMSI), driven by continuous high current cycling and electrolyte motion, which is intensified by higher holder stiffness but not by offset pressure. These insights are crucial for improving the accuracy of accelerated aging tests and enhancing battery lifespan predictions.}, language = {en} } @article{YuKiranEhrensbergeretal.2025, author = {Yu, Qing and Kiran, Iqra and Ehrensberger, Moritz and Streck, Luiza and Roth, Thomas and Jossen, Andreas and Endisch, Christian and Lewerenz, Meinert}, title = {Assigning Calendar Aging during Open Circuit and Float Current Analysis to Anode and Cathode Aging Using Three-Electrode Cells}, volume = {172}, pages = {060523}, journal = {Journal of the Electrochemical Society}, number = {6}, publisher = {IOP Publishing}, address = {Bristol}, issn = {1945-7111}, doi = {https://doi.org/10.1149/1945-7111/ade295}, year = {2025}, abstract = {Analyzing calendar aging by float current analysis, instead of solely repeating capacity tests, gains more insights into aging. However, the underlying mechanisms of the recharge current required to keep the voltage constant are not yet fully understood. Therefore, this study performs float current and additional open circuit voltage (OCV) tests on 3-electrode cells for four different voltages at 30 °C. By monitoring the potentials of the anode and the cathode over time individually, the aging rate on both electrodes and the present capacity can be calculated based on adjusting the electrode-specific OCV curves according to the voltage slippery theory. The electrode-specific aging and the capacity prediction show high agreement among both methods and the capacity tests at the end of the experiment. As a result, the capacity loss appears linear-like and is associated with the loss of active lithium mainly due to SEI formation on the anode. Additionally, a significant cathode voltage decay is observed especially for higher cell voltage. According to the literature, this is associated with cathode lithiation where the conductive salt is decomposed by inserting active lithium into the cathode masking SEI losses. Finally, OCV and float current analysis return comparable results and support present 2-electrode evaluation approaches.}, language = {en} } @inproceedings{RauscherStenzelEndisch2025, author = {Rauscher, Andreas and Stenzel, Peer and Endisch, Christian}, title = {Investigation of Factors Influencing the End-of-Line Partial Discharge Testing of Electrical Machines}, booktitle = {2025 IEEE Workshop on Electrical Machines Design, Control and Diagnosis (WEMDCD)}, publisher = {IEEE}, address = {Piscataway}, doi = {https://doi.org/10.1109/WEMDCD61816.2025.11014117}, year = {2025}, language = {en} } @article{SchreiberLinSommeretal.2025, author = {Schreiber, Markus and Lin, Yilei and Sommer, Alessandro and Wassiliadis, Nikolaos and Morales Torricos, Pablo and Rogge, Marcel and Lewerenz, Meinert and Grosu, Cristina and Endisch, Christian and Jossen, Andreas and Lienkamp, Markus}, title = {Apparent vs. true battery aging: Impact of various load characteristics on accelerated aging tests}, volume = {2025}, pages = {116924}, journal = {Journal of Energy Storage}, number = {127}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2352-1538}, doi = {https://doi.org/10.1016/j.est.2025.116924}, year = {2025}, abstract = {Vehicle applications involve highly dynamic and variable operating conditions. These result from changing driving profiles and diverse driving behaviors. To accelerate battery aging tests, experiments are often based on constant load cycles. While efficient, this approach distorts the natural degradation behavior of the cells. This study compares cell aging under real-world and laboratory load conditions. For this purpose, we compare realistic driving profiles measured in a test vehicle in the field with synthetic constant power cycles. Average discharge power and charging sequences are kept identical for comparability. Results show that constant power cycles cause stronger cell aging than dynamic loads. Differential voltage analysis indicates more lithium inventory loss and active material loss at the negative electrode under static loads. Static loading also leads to strong inhomogeneity in the negative electrode and altered charge transfer and diffusion kinetics, as shown by impedance data. After 15 months of rest, the cells recovered up to 52 of lost capacity and 66 of the resistance increase. Impedance assessment and differential voltage analysis confirm the recovery and rehomogenization of the negative electrode. These findings show that conventional accelerated tests are strongly influenced by relaxation and load dynamics. As a result, their applicability to specific use cases, such as automotive applications, is strongly limited . Therefore, andraditional test strategies require reconsideration and redesign.}, language = {en} } @article{AzzamAydinEndischetal.2025, author = {Azzam, Mohamed and Aydin, Atakhan and Endisch, Christian and Sauer, Dirk Uwe and Lewerenz, Meinert}, title = {Float Current Analysis for Lithium-Ion Battery Aging: Insights into SEI Growth and Cathode Lithiation with EIS and ICP OES}, volume = {172}, pages = {070529}, journal = {Journal of The Electrochemical Society}, number = {7}, publisher = {IOP Publishing}, address = {Bristol}, issn = {1945-7111}, doi = {https://doi.org/10.1149/1945-7111/adef85}, year = {2025}, abstract = {This study investigates calendar-aging mechanisms in lithium-ion batteries, focusing on cathode lithiation due to decomposition of conductive salt and SEI growth, by correlating quantified float currents, capacity loss rates, and pulse resistances with changes in electrochemical impedance spectroscopy (EIS) spectra. Seven SamSung 25 R cells are aged at different float voltages with periodic EIS measurements at 30 °C. Using a pre-characterization cell, the internal processes via EIS are allocated across various states of charge and temperatures and GITT measurements are performed to derive scaling factors. GITT, float currents and capacity loss rate measurements at 30 °C enables the separation of SEI growth ISEI growth and cathode lithiation current ICL based on float current behavior across a temperature range of 5 °C to 50 °C. The distribution of relaxation times (DRT) method is employed to deconvolute overlapping electrochemical processes. EIS and DRT analyses showed significant changes in cathode charge transfer resistance and diffusion, confirming that cathode lithiation correlates substantially to elevated internal resistance at high cell voltages. The theory of ISEI growth and ICL is further supported using inductively coupled plasma atomic emission spectroscopy by quantifying elemental inventory changes and linking phosphorus release and lithium consumption to degradation mechanisms.}, language = {en} } @inproceedings{GankinMayerZinnetal.2021, author = {Gankin, Dennis and Mayer, Sebastian and Zinn, Jonas and Vogel-Heuser, Birgit and Endisch, Christian}, title = {Modular Production Control with Multi-Agent Deep Q-Learning}, booktitle = {Proceedings: 2021 26th IEEE International Conference on Emerging Technologies and Factory Automation (ETFA)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-2989-1}, doi = {https://doi.org/10.1109/ETFA45728.2021.9613177}, year = {2021}, language = {en} } @article{SchmidKneidingerEndisch2020, author = {Schmid, Michael and Kneidinger, Hans-Georg and Endisch, Christian}, title = {Data-driven fault diagnosis in battery systems through cross-cell monitoring}, volume = {21}, journal = {IEEE Sensors Journal}, number = {2}, publisher = {IEEE}, address = {New York}, issn = {1558-1748}, doi = {https://doi.org/10.1109/JSEN.2020.3017812}, pages = {1829 -- 1837}, year = {2020}, language = {en} } @article{KleinerSinghSchmidetal.2020, author = {Kleiner, Jan and Singh, Randeep and Schmid, Michael and Komsiyska, Lidiya and Elger, Gordon and Endisch, Christian}, title = {Influence of heat pipe assisted terminal cooling on the thermal behavior of a large prismatic lithium-ion cell during fast charging in electric vehicles}, volume = {2021}, pages = {116328}, journal = {Applied Thermal Engineering}, number = {188}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1359-4311}, doi = {https://doi.org/10.1016/j.applthermaleng.2020.116328}, year = {2020}, language = {en} } @article{SchmidGebauerEndisch2021, author = {Schmid, Michael and Gebauer, Emanuel and Endisch, Christian}, title = {Structural analysis in reconfigurable battery systems for active fault diagnosis}, volume = {36}, journal = {IEEE Transactions on Power Electronics}, number = {8}, publisher = {IEEE}, address = {New York}, issn = {1941-0107}, doi = {https://doi.org/10.1109/TPEL.2021.3049573}, pages = {8672 -- 8684}, year = {2021}, language = {en} } @inbook{AltmannshoferEndisch2017, author = {Altmannshofer, Simon and Endisch, Christian}, title = {Robuste Parametersch{\"a}tzung f{\"u}r reale Anwendungen}, booktitle = {Intelligente Verfahren: Identifikation und Regelung nichtlinearer Systeme}, editor = {Schr{\"o}der, Dierk and Buss, Martin}, edition = {2., erweiterte Auflage}, publisher = {Springer Vieweg}, address = {Berlin}, isbn = {978-3-662-55327-5}, doi = {https://doi.org/10.1007/978-3-662-55327-5_12}, pages = {399 -- 472}, year = {2017}, language = {de} } @article{WiedererLeitnerEndischetal.2016, author = {Wiederer, Julian and Leitner, Lukas and Endisch, Christian and Reiss, Hans}, title = {Fast Crank-Angle Based 0D Simulation of Combustion Engine Cold Tests including Manufacturing Faults and Production Spread}, volume = {9}, journal = {SAE International Journal of Passenger Cars - Mechanical Systems}, number = {1}, publisher = {SAE International}, address = {Warrendale}, issn = {1946-4002}, doi = {https://doi.org/10.4271/2016-01-1374}, pages = {321 -- 335}, year = {2016}, language = {en} } @article{JardanStumpfVargaetal.2016, author = {J{\´a}rd{\´a}n, Rafael K. and Stumpf, P{\´e}ter and Varga, Zolt{\´a}n and Endisch, Christian and Sipos, P{\´e}ter and Simon, Mikl{\´o}s}, title = {Laboratory system for measurement of iron losses in high speed drives}, volume = {41}, journal = {International Journal of Hydrogen Energy}, number = {29}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0360-3199}, doi = {https://doi.org/10.1016/j.ijhydene.2016.01.061}, pages = {12650 -- 12658}, year = {2016}, language = {en} } @article{StolzeKaramanakosKenneletal.2014, author = {Stolze, Peter and Karamanakos, Petros and Kennel, Ralph and Manias, Stefanos and Endisch, Christian}, title = {Effective variable switching point predictive current control for ac low-voltage drives}, volume = {88}, journal = {International Journal of Control}, number = {7}, publisher = {Taylor \& Francis}, address = {London}, issn = {0020-7179}, doi = {https://doi.org/10.1080/00207179.2014.942699}, pages = {1366 -- 1378}, year = {2014}, language = {en} } @inproceedings{OkonOpferkuchEndisch2020, author = {Okon, Michael and Opferkuch, Johannes and Endisch, Christian}, title = {Modular gear transmission model for analyzing production tolerances in electric drivetrains}, booktitle = {Proceedings, 2020 IEEE International Conference on Industrial Technology}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-5754-2}, doi = {https://doi.org/10.1109/ICIT45562.2020.9067240}, pages = {709 -- 716}, year = {2020}, language = {en} } @inproceedings{GerngrossKohlerEndischetal.2020, author = {Gerngroß, Martin and Kohler, Markus and Endisch, Christian and Kennel, Ralph}, title = {Model-based control of nonlinear wire tension in dynamic needle winding processes}, booktitle = {Proceedings, 2020 IEEE International Conference on Industrial Technology}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-5754-2}, doi = {https://doi.org/10.1109/ICIT45562.2020.9067168}, pages = {381 -- 388}, year = {2020}, language = {en} } @inproceedings{KleinerKomsiyskaElgeretal.2019, author = {Kleiner, Jan and Komsiyska, Lidiya and Elger, Gordon and Endisch, Christian}, title = {Modelling of 3D temperature behavior of prismatic lithium-ion cell with focus on experimental validation under battery electric vehicle conditions}, booktitle = {2019 25th International Workshop on Thermal Investigations of ICs and Systems (THERMINIC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-2078-2}, doi = {https://doi.org/10.1109/THERMINIC.2019.8923604}, year = {2019}, language = {en} } @inproceedings{SchneiderEndisch2020, author = {Schneider, Dominik and Endisch, Christian}, title = {Robustness and reliability of model-based sensor data fusion in a lithium-ion battery system}, booktitle = {IEEE CCTA 2020, 4th IEEE Conference on Control Technology and Applications}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-7140-1}, doi = {https://doi.org/10.1109/CCTA41146.2020.9206336}, pages = {685 -- 691}, year = {2020}, language = {en} } @inproceedings{SchneiderLiebhartEndisch2021, author = {Schneider, Dominik and Liebhart, Bernhard and Endisch, Christian}, title = {Adaptive Variance Estimation of Sensor Noise within a Sensor Data Fusion Framework}, booktitle = {2021 IEEE International Instrumentation and Measurement Technology Conference (I2MTC 2021) Proceedings}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-9539-1}, issn = {2642-2077}, doi = {https://doi.org/10.1109/I2MTC50364.2021.9459790}, year = {2021}, language = {en} } @article{TheilerSchneiderEndisch2022, author = {Theiler, Michael and Schneider, Dominik and Endisch, Christian}, title = {Kalman Filter Tuning Using Multi-Objective Genetic Algorithm for State and Parameter Estimation of Lithium-Ion Cells}, volume = {8}, pages = {104}, journal = {Batteries}, number = {9}, publisher = {MDPI}, address = {Basel}, issn = {2313-0105}, doi = {https://doi.org/10.3390/batteries8090104}, year = {2022}, abstract = {To ensure a reliable and safe operation of battery systems in various applications, the system's internal states must be observed with high accuracy. Hereby, the Kalman filter is a frequently used and well-known tool to estimate the states and model parameters of a lithium-ion cell. A strong requirement is the selection of a suitable model and a reasonable initialization, otherwise the algorithm's estimation might be insufficient. Especially the process noise parametrization poses a difficult task, since it is an abstract parameter and often optimized by an arbitrary trial-and-error principle. In this work, a traceable procedure based on the genetic algorithm is introduced to determine the process noise offline considering the estimation error and filter consistency. Hereby, the parameters found are independent of the researcher's experience. Results are validated with a simulative and experimental study, using an NCA/graphite lithium-ion cell. After the transient phase, the estimation error of the state-of-charge is lower than 0.6\% and for internal resistance smaller than 4mΩ while the corresponding estimated covariances fit the error well.}, language = {en} } @inproceedings{NachtsheimHartmannEndisch2022, author = {Nachtsheim, Martin and Hartmann, Thomas and Endisch, Christian}, title = {Physically Inspired Neural Network for Modeling Induction Machine Nonlinear Magnetic Saturation}, booktitle = {ITEC+2022: 2022 IEEE/AIAA Transportation Electrification Conference and Electric Aircraft Technologies Symposium (ITEC+EATS)}, publisher = {IEEE}, address = {Piscataway (NJ)}, isbn = {978-1-6654-0560-7}, doi = {https://doi.org/10.1109/ITEC53557.2022.9813908}, pages = {874 -- 881}, year = {2022}, language = {en} } @inproceedings{KohlerFendtEndisch2022, author = {Kohler, Markus and Fendt, David and Endisch, Christian}, title = {Modeling Geometric Wire Bending Behavior in Needle Winding Processes Using Circular Arcs with Tangential Linear Functions}, booktitle = {ITEC+2022: 2022 IEEE/AIAA Transportation Electrification Conference and Electric Aircraft Technologies Symposium (ITEC+EATS)}, publisher = {IEEE}, address = {Piscataway (NJ)}, isbn = {978-1-6654-0560-7}, doi = {https://doi.org/10.1109/ITEC53557.2022.9814041}, pages = {894 -- 901}, year = {2022}, language = {en} } @inproceedings{MayerHoehmeGankinetal.2020, author = {Mayer, Sebastian and H{\"o}hme, Nikolas and Gankin, Dennis and Endisch, Christian}, title = {Adaptive Production Control in a Modular Assembly System - Towards an Agent-based Approach}, booktitle = {Proceedings, 2019 IEEE 17th International Conference on Industrial Informatics (INDIN)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-2927-3}, doi = {https://doi.org/10.1109/INDIN41052.2019.8972152}, pages = {45 -- 52}, year = {2020}, language = {en} } @inproceedings{MayerEndisch2019, author = {Mayer, Sebastian and Endisch, Christian}, title = {Adaptive production control in a modular assembly system based on partial look-ahead scheduling}, booktitle = {Proceedings, 2019 IEEE International Conference on Mechatronics (ICM)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-5386-6959-4}, doi = {https://doi.org/10.1109/ICMECH.2019.8722904}, pages = {293 -- 300}, year = {2019}, language = {en} } @inproceedings{HerrmannStenzelVoegeleetal.2016, author = {Herrmann, Patrick and Stenzel, Peer and V{\"o}gele, Ulrich and Endisch, Christian}, title = {Optimization Algorithms for Maximizing the Slot Filling Factor of Technically Feasible Slot Geometries and Winding Layouts}, booktitle = {2016 6th International Electric Drives Production Conference (E|DPC): Proceedings}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-5090-2909-9}, doi = {https://doi.org/10.1109/EDPC.2016.7851327}, year = {2016}, language = {en} } @inproceedings{MuellerEndisch2016, author = {M{\"u}ller, Tino and Endisch, Christian}, title = {Compensation techniques for iterative rig control in multi-axial durability testing}, booktitle = {2016 IEEE 21st International Conference on Emerging Technologies and Factory Automation (ETFA)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-5090-1314-2}, doi = {https://doi.org/10.1109/ETFA.2016.7733517}, year = {2016}, language = {en} } @inproceedings{LeitnerLagrangeEndisch2016, author = {Leitner, Lukas and Lagrange, Antoine and Endisch, Christian}, title = {End-of-line fault detection for combustion engines using one-class classification}, booktitle = {2016 IEEE International Conference on Advanced Intelligent Mechatronics (AIM)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-5090-2065-2}, doi = {https://doi.org/10.1109/AIM.2016.7576768}, pages = {207 -- 213}, year = {2016}, language = {en} }