TY - CHAP A1 - Bohn, Gunther A1 - Taub, J. A1 - Linke, Andreas A1 - Bayer, Sven A1 - Oeser, David A1 - Ziegler, Andreas A1 - Ettl, P. A1 - Ackva, Ansgar T1 - High-resolution Interferometric Measurement of Thickness Change on a Lithium-Ion Pouch Battery T2 - 3rd International Conference on Environmental and Energy Engineering (IC3E 2019) N2 - Volume change of graphite leads to change in thickness of battery storage layers during discharging and charging. Pouch cell lithium ion batteries are used in the field of electric vehicles and solar home storage. This paper shows a measurement setup for the three-dimensional measurement of thickness change on a flat 6.7mm thick pouch cell using a white light interferometer. With a measuring field of 7.05mm diameter the resulting 3D thickness change record contains 226000 3D readings. The measuring points have a lateral distance of 13.1μm. The repeatability of the measurement is 312.8nm for the individual values and 64.1nm for the average value. In addition, this paper shows how the storage capacity of this pouch cell drops over 30 charge cycles. Y1 - 2019 U6 - https://doi.org/10.1088/1755-1315/281/1/012030 VL - 281 ER - TY - CHAP A1 - Buschhaus, Arnd A1 - Blank, Andreas A1 - Ziegler, Christian A1 - Franke, Jörg T1 - Highly efficient control system enabling robot accuracy improvement T2 - 5TH CIRP Conference on Assembly Technologies and Systems (CATS), Dresden N2 - A significant challenge when using industrial robots as flexible handling devices - for example in the area of creating miniaturized conductive patterns on three dimensional molded interconnect devices - is their relatively low absolute accuracy, which is caused by inaccuracies in the robots kinematic chain. This characteristic has to be considered, especially if complex and precise 3D-movements are needed. One approach to overcome this problem investigated at FAPS is the usage of a specially designed robot control system with parallel data processing for real-time correction value determination and usage of these values for remote control of a robot to improve its accuracy. The developed control system utilizes existing network technologies and uses data of sensor systems for continuous process monitoring to derive the robots actual state in course of its movement. In case of a high speed camera the image data is acquired by the control system via a first thread and subsequently the actual robot position is calculated based on this data. At the same time, for determining the robots target state, the system continuously requests the robots nominal position from the robot controller by utilizing a parallel second thread. The information describing the robots actual state is then compared with the sensor data for calculating offset values. These offset values are subsequently filtered and a correction value is calculated. In a third parallel thread new movement instructions are generated, considering the offset values as well as the robots target trajectory. Finally, for remote control of the robot, these movement instructions are transferred to the robot controller. Y1 - 2014 U6 - https://doi.org/10.1016/j.procir.2014.03.200 VL - 23 SP - 200 EP - 205 ER - TY - JOUR A1 - Ziegler, Andreas A1 - Oeser, David A1 - Hein, Thiemo A1 - Montesinos Miracle, Daniel A1 - Ackva, Ansgar T1 - Reducing Cell to Cell Variation of Lithium-Ion Battery Packs During Operation Y1 - 2021 U6 - https://doi.org/10.1109/ACCESS.2021.3057125 VL - 9 SP - 24994 EP - 25001 ER - TY - JOUR A1 - Ziegler, Andreas A1 - Oeser, David A1 - Hein, Thiemo A1 - Montesinos Miracle, Daniel A1 - Ackva, Ansgar T1 - Run to Failure: Aging of Commercial Battery Cells beyond Their End of Life JF - Energies Y1 - 2020 U6 - https://doi.org/10.3390/en13081858 VL - 13 IS - 8 ER - TY - THES A1 - Ziegler, Andreas Rainer ED - Montesinos Miracle, Daniel ED - Ackva, Ansgar T1 - Possibilities and limitations of active battery management systems for lithium-ion batteries N2 - (English) Lithium-Ion Batteries (LIBs) are being used in more and more areas of application. At the same time, their chemical composition and their designs are constantly evolving. Major developments are also taking place in the field of Battery Management Systems (BMSs), which are essential for the safe operation of LIBs. The focus is on intelligent charge redistribution between individual cells, called Active Balancing (AB). This thesis deals with the possibilities and limitations of AB. An empirical long-term experiment provides new insights into the ageing behaviour of batteries that are actively balanced during their entire service life. The main objective of this work is to to demonstrate influences on the ageing behaviour of batteries that are still unknown at present. A literature study shows that previous work in this area is often based on theoretical approaches and rarely has a functional proof through measurement results. Most significant statements from literature are examined. These include the increase in discharge capacity, energy efficiency and service life associated with AB, as well as lower parameter variation of the individual cells installed in the battery. Before starting the empirical experiment, the current state of the art is captured and a universal AB topology is selected from a large number of known systems. The operating behaviour as well as the balancing algorithms are explained in detail in order to be able to understand the influences occurring during the ageing of the batteries. The ageing experiment itself is a comparison test between commercial Passive Balancing (PB) and the novel AB. Two identical battery packs are aged under uniform conditions, but with the two different BMSs mentioned above. At the end of the ageing process, the battery packs are disassembled and the parameters of all individual cells are determined for further investigation. The main contribution of this work is the proof of effects through AB, especially with large battery loads. Both the increase in discharge capacity and the service life are demonstrated. The work shows how parameter variation of individual cells can be made visible during operation. It also presents diagnosis and calculation methods. The energetic efficiency of the batteries cannot be increased, since the self-consumption of the power electronics of the AB system is always higher than with PB. However, the overall efficiency of the battery increases due to an increase in capacity and an extension of the service life. The thesis also shows that with lower battery loads, the use of AB is not beneficial any more or may lead to negative effects. In such applications conventional PB is sufficient. The results obtained during pack ageing are additionally substantiated and extended by the measurement results of the individual cells. At the end of the thesis, all results and contributions are summarised. Suggestions for optimisation as well as further research ideas are presented as a possible starting point for further scientific studies. (Català) Les bateries d’ions de liti (Lithium Ion Batteries, en anglès) s’usen en més aplicacions. Al mateix temps, la seva composició química i dissenys estan en evolució constant. Els sistemes de gestió del bateries (Battery Management Systems, en anglès), que són essencials per l’operació de les LIB, també estan en constant evolució. El focus principal està en la distribució intel·ligent de càrrega elèctrica entre cel·les individuals, l’anomenat balanceig actiu (Active Balancing, en anglès). Un assaig empíric, de llarga durada, com el dut a terme en aquest treball, dona molt informació en el procés d’envelliment de les cel·les durant tota la seva vida. El principal objectiu d’aquest treball és demostrar les influències encara desconegudes en el procés d’envelliment de les cel·les. L’estudi de la literatura mostra que el treball previ en aquesta àrea està sovint basat en aproximacions teòriques i estranyament ensenya resultats empírics que ho corroborin. En aquest treball s’examinen la majoria de presumpcions que es poden trobar a la literatura. Aquestes inclouen l’increment en la capacitat, l’eficiència energètica i la vida útil associada a un balanceig actiu de les cel·les, així com la reducció de la variació dels paràmetres de cada cel·la en una bateria. Abans de procedir amb l’experiment empíric, es revisa l’estat de l’art en els aspectes fonamentals per aquest estudi. També se selecciona una tipologia de sistema de balanceig actiu per tal de realitzar l’experiment. El treball detalla el procediment d’operació així com l’algoritme de balanceig actiu implementat per tal d’entendre els fenòmens que influencien la degradació de les cel·les durant la seva vida. L’experiment d’envelliment és una comparació entre un sistema de balanceig passiu (Passive Balancing, en anglès) i un de balanceig actiu. Per això s’escullen dues bateries idèntiques, però gestionades diferentment per dos sistemes de gestió diferents. Al final de l’assaig, les bateries es desmunten i s’analitza cada cel·la de forma individual per tal de determinar-ne els seus paràmetres i el seu envelliment. La principal contribució d’aquest treball es el demostrar els efectes del balanceig actiu , sobretot en bateries amb una càrrega elevada. El treball demostra que el balanceig actiu millor gla capacitat de la bateria i la vida útil. El treball també mostra com la variació dels paràmetres de les cel·les es pot fer visible durant la seva operació. També presenta nous mètodes de diagnosi i càlcul d’aquests paràmetres. L’eficiència energètica de les bateries no es pot augmentar degut al consum propi i les pèrdues del sistema de balanceig actiu basat en electrònica de potencia. Si que augmenta l’eficiència global de la bateria, ja que augmenta la seva capacitat i la vida útil. El treball també mostra que en bateries sotmeses a baixa càrrega, el balanceig actiu no aporta cap avantatge respecte el balanceig passiu. Fins i tot en algunes situacions, els efectes del balanceig actiu són negatius. En aquestes aplicacions, es recomana l’ús d’un sistema de balanceig passiu. Els resultats obtinguts durant l’assaig de la bateria queden reforçats quan es fa l’anàlisi de cada cel·la de forma individual. Al final del treball, es resumeixen tots els resultats a més de proporcionar suggereixes per la optimització així com possibles línies de futures investigacions Y1 - 2022 U6 - https://doi.org/10.5821/dissertation-2117-380367 PB - Universitat Politècnica de Catalunya ER - TY - JOUR A1 - Oeser, David A1 - Hein, Thiemo A1 - Ziegler, Andreas A1 - Seefried, Michael A1 - Gielinger, Sebastian A1 - Montesinos-Miracle, Daniel A1 - Bohn, Gunther A1 - Ackva, Ansgar T1 - Age-related development of cell-to-cell variation under various operating conditions in commercial NMC/graphite lithium-ion cells JF - Journal of Energy Storage N2 - In real applications, lithium-ion cells are usually used in individual interconnections, with the worst cell determining capacity, performance and service life. Due to different ageing rates of the assembled cells, cell-to-cell variation changes over lifetime. In literature, cell-to-cell variation is usually investigated near room temperature under one operating condition. Data regarding cell-to-cell variation above and below room temperature under different operating conditions are hard to find. To fill the gap in literature, this study considers cell-to-cell variation as a function of different charge/discharge currents at ambient temperatures between 0 °C and 40 °C on commercial NMC/graphite cells (Samsung SDI ICR18650-26J). The results demonstrate that cell-to-cell variation strongly depends on the selected operating conditions. In particular, operating conditions near the lithium plating boundary at the beginning of the ageing process have a particularly high risk of developing a pronounced variation. Fast charging or charging at lower temperatures should therefore be avoided. Operation at moderate temperatures and currents, on the other hand, only leads to a slight increase in cell-to-cell variation in the tests carried out. A 24-month storage during the testing period at 30% SOC and room temperature of the same cells shows even a slight reduction in cell-to-cell variation. Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:863-opus-57585 VL - 101 PB - Elsevier ER - TY - THES A1 - Ziegler, Andreas ED - Montesinos-Miracle, Daniel ED - Ackva, Ansgar T1 - Possibilities and limitations of active battery management systems for lithium-ion batteries N2 - Lithium-Ion Batteries (LIBs) are being used in more and more areas of application. At the same time, their chemical composition and their designs are constantly evolving. Major developments are also taking place in the field of Battery Management Systems (BMSs), which are essential for the safe operation of LIBs. The focus is on intelligent charge redistribution between individual cells, called Active Balancing (AB). This thesis deals with the possibilities and limitations of AB. An empirical long-term experiment provides new insights into the ageing behaviour of batteries that are actively balanced during their entire service life. The main objective of this work is to to demonstrate influences on the ageing behaviour of batteries that are still unknown at present. A literature study shows that previous work in this area is often based on theoretical approaches and rarely has a functional proof through measurement results. Most significant statements from literature are examined. These include the increase in discharge capacity, energy efficiency and service life associated with AB, as well as lower parameter variation of the individual cells installed in the battery. Before starting the empirical experiment, the current state of the art is captured and a universal AB topology is selected from a large number of known systems. The operating behaviour as well as the balancing algorithms are explained in detail in order to be able to understand the influences occurring during the ageing of the batteries. The ageing experiment itself is a comparison test between commercial Passive Balancing (PB) and the novel AB. Two identical battery packs are aged under uniform conditions, but with the two different BMSs mentioned above. At the end of the ageing process, the battery packs are disassembled and the parameters of all individual cells are determined for further investigation. The main contribution of this work is the proof of effects through AB, especially with large battery loads. Both the increase in discharge capacity and the service life are demonstrated. The work shows how parameter variation of individual cells can be made visible during operation. It also presents diagnosis and calculation methods. The energetic efficiency of the batteries cannot be increased, since the self-consumption of the power electronics of the AB system is always higher than with PB. However, the overall efficiency of the battery increases due to an increase in capacity and an extension of the service life. The thesis also shows that with lower battery loads, the use of AB is not beneficial any more or may lead to negative effects. In such applications conventional PB is sufficient. The results obtained during pack ageing are additionally substantiated and extended by the measurement results of the individual cells. At the end of the thesis, all results and contributions are summarised. Suggestions for optimisation as well as further research ideas are presented as a possible starting point for further scientific studies. Y1 - 2023 UR - http://hdl.handle.net/10803/687388 ER - TY - JOUR A1 - Hein, Thiemo A1 - Oeser, David A1 - Ziegler, Andreas A1 - Montesinos-Miracle, Daniel A1 - Ackva, Ansgar T1 - Aging Determination of Series-Connected Lithium-Ion Cells Independent of Module Design JF - Batteries N2 - In this work, a battery consisting of eight commercial NMC/graphite cells connected in series was cycled to 60% of its initial capacity. During the test, special care was taken to ensure that the results were not influenced by either the module assembly or the module design. For this purpose, the cells were virtually connected in a laboratory environment with the help of the test device as if they were operated together in a battery. Extrinsic influences that affect cell aging were thus reduced to a minimum. Differential Voltage Analysis (DVA), Electrochemical Impedance Spectrum (EIS), and relaxation measurements were performed to analyze the aging behavior of each cell. The results show that despite a theoretically perfect module design, Cell-to-Cell Variations (CtCV) occurred during aging. The shifting Depth of Discharge (DoD) values among the cells further amplify CtCV. Lithium plating was also observed in the faster aging cells after cyclic aging, suggesting that this aging effect contributes significantly to the development of CtCV. After the aging test, the battery was equipped with an active balancing system that maximizes capacity utilization. More important, the balancing charges which are calculated iteratively within the used balancing algorithm show a strong correlation to the pure capacity losses and thus provide a new way to determine the capacity values of each cell individually without disassembling the battery. Y1 - 2023 U6 - https://doi.org/10.3390/batteries9030172 VL - 9 IS - 3 ER - TY - JOUR A1 - Gielinger, Sebastian A1 - Hein, Thiemo A1 - Ziegler, Andreas A1 - Oeser, David A1 - Breitfelder, Sebastian A1 - Bohn, Gunther T1 - A Short Time Expansion Measurement Method for the Detection of Aging Effect of Lithium Ion Cells Using a High Resolution Laser Interfometric Setup JF - IEEE Access N2 - In this work a new expansion measurement methodology for the detection of ageing mechanisms in lithium ion cells is described and evaluated. For this purpose, a polarization-optical homodyne Michelson interferometer with a resolution of approx. 10 nm was set up to allow measurements of different cell types, cell sizes, and cell chemistry within a Memmert IP55 climate chamber. The used interferometric measurement setup is ten times more accurate than measurement systems commonly used for battery measurements in the literature. The better spatial resolution of an interferometer setup enables the recording of the expansion response to short current pulses with low transferred charge. This offers the possibility to detect ageing mechanisms such as lithium plating within short measuring times. With this measurement setup, a lithium iron phosphate pouch cell from the company A123, with the model identification AMP20M1HD-A, is measured. First, an expansion measurement over a full charge and discharge cycle with a constant load of ± C 20 (b=1 A) is performed. Here, the cell undergoes an expansion of about 42 μm. Subsequently, the in this work proposed measurement methodology is presented to show the influence of effects such as the formation of overshooting graphite stages or lithium plating on cell expansion. For this purpose, at a residual capacitance of 50%, the cell is pulsed with current of different intensity I ∈ {±20A,±80A} for t = {240 s, 60 s}, at T = {10 ◦C, 20 ◦C, 30 ◦C}, respectively, and the mechanical response is recorded using the high accuracy interferometer setup. A mechanical relaxation of the cell after the pulses with a time constant in the range between 10 s and 20 s can be observed. It is shown that this relaxation behavior can be associated with effects of the anode known from the literature, such as the formation of overshooting graphite stages or lithium plating. These effects can be recorded by the very high-resolution measurement already with little transferred charge and within a short measurement time. Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:863-opus-53654 VL - 11 PB - IEEE ER - TY - JOUR A1 - Hein, Thiemo A1 - Ziegler, Andreas A1 - Oeser, David A1 - Ackva, Ansgar T1 - A capacity-based equalization method for aged lithium-ion batteries in electric vehicles JF - Electric power systems research Y1 - 2021 U6 - https://doi.org/10.1016/j.epsr.2020.106898 SN - 0378-7796 VL - 191 ER - TY - CHAP A1 - Ziegler, Andreas A1 - Oeser, David A1 - Hein, Thiemo A1 - Ackva, Ansgar T1 - Development and Application of an Active Balancing System for Lithium-Ion Cells T2 - 2019 IEEE Vehicle Power and Propulsion Conference (VPPC) Y1 - 2019 SN - 978-1-7281-1249-7 U6 - https://doi.org/10.1109/VPPC46532.2019.8952317 SP - 1 EP - 6 ER - TY - CHAP A1 - Ziegler, Andreas A1 - Oeser, David A1 - Arndt, Bernhard A1 - Ackva, Ansgar ED - University of Košice, Technical T1 - A Universal, Modular and Bidirectional Active Balancing System for Lithium-Ion Cells T2 - Proceedings of the 10th International Scientific Symposium on Electrical Power Engineering Y1 - 2019 SN - 978-80-553-3324-3 SP - 400 EP - 405 ER - TY - CHAP A1 - Ziegler, Andreas A1 - Oeser, David A1 - Arndt, Bernhard A1 - Ackva, Ansgar T1 - Comparison of Active and Passive Balancing by a Long Term Test Including a Post-Mortem Analysis of all Single Battery Cells T2 - 2018 International IEEE Conference and Workshop in Óbuda on Electrical and Power Engineering (CANDO-EPE) Y1 - 2018 SN - 978-1-7281-1154-4 U6 - https://doi.org/10.1109/CANDO-EPE.2018.8601165 SP - 15 EP - 20 ER - TY - CHAP A1 - Oeser, David A1 - Ziegler, Andreas A1 - Arndt, Bernhard A1 - Ackva, Ansgar T1 - Effectiveness of Active Balancing on High Dispersion Batteries T2 - 2018 International IEEE Conference and Workshop in Óbuda on Electrical and Power Engineering (CANDO-EPE) Y1 - 2018 SN - 978-1-7281-1154-4 U6 - https://doi.org/10.1109/CANDO-EPE.2018.8601129 SP - 21 EP - 26 ER - TY - JOUR A1 - Oeser, David A1 - Ziegler, Andreas A1 - Ackva, Ansgar T1 - Single cell analysis of lithium-ion e-bike batteries aged under various conditions JF - Journal of power sources Y1 - 2018 U6 - https://doi.org/10.1016/j.jpowsour.2018.06.101 SN - 0378-7753 VL - 397 SP - 25 EP - 31 ER - TY - THES A1 - Ziegler, Andreas T1 - Erweiterung und Optimierung eines aktiven Batteriemanagementsystems für Fahrzeuge Y1 - 2016 ER - TY - THES A1 - Ziegler, Andreas T1 - Leistungselektronische Schaltungen für das aktive Batteriemanagement in Hybrid- und Elektrofahrzeugen in Verbindung mit deren Ladesystemen Y1 - 2017 ER -