Lead –acid batteries are the most common type of secondary cells used in automotive industry. This diploma thesis deals with the influence of temperature on their lifetime. In the preamble of this work is shortly described their history, division, construction and processes during battery operation. There are noted unfavorable phenomena which have an impact on increasing the temperature inside the battery. The first experimental part is devoted to evaluation the effects of addition on the temperature rise during charging. The second part is focused on conditions simulation in hot areas at the temperature above 30 °C and effects of this temperature on the function of lead – acid batteries.

Målet med arbetet var att undersöka vilka tekniker som finns för att bekämpa bränder i elbilar ombord på fartyg och vilka farliga gaser som elbilar med litiumjonbatterier avger när de brinner.  För att svara på dessa gjordes en metaanalys för att undersöka hälsoriskerna med några av de farliga gaserna som uppstår, hur man minskar hälsorisken som följer bränder i litiumjonbatteri genom användning av särskild utrustning, samt vilka åtgärder som går att utnyttja ombord på fartyg,   Litiumjonbatterier har även visats sig problematiska att släcka, men det har dykt upp särskilda släckmedel för att bekämpa dessa bränder. I arbetet undersöks några av dessa släckmedel. Då teknologin bakom batteridrift i fordon fortfarande är relativt ny och precis börjar bli vanligt på våra gator, så finns det ännu inte mycket direktiv om vilka åtgärder som bör tas för en effektiv släckning, förhindra återtändning och skydda personers hälsa ombord på fartyg. Därför har vi valt att titta på vilka rutiner det finns i land för att se om de går att tillämpa ombord. / The purpose of this thesis was to examine which techniques exists to fight fires in electrical vehicles aboard ships and which harmful substances electrical vehicles releases when burning. To answer these questions, we performed a meta-analysis to understand some of the harmful gases that will be present during an EV fire, how to minimize the health hazard that comes with fires in lithium-ion batteries using certain equipment and what measures that can be taken aboard ships.  Li-ion batteries have also proven to be problematic to extinguish, but there have emerged certain extinguishing agents to fight these types of fires. In this thesis we look at some of these extinguishing agents. As technology being used in battery powered vehicles is still new and just becoming common on our streets, there is not a whole lot of directives on how to be effective in extinguishing them, prevent reignition and protect the health of people abord ships. That is why we have chosen to look at what is being used on shore and see if it can be applied on ships.

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Diese Arbeit beschäftigt sich mit dem besonders kritischen Ausschaltvorgang bipolarer Leistungsdioden, bei dem das im Durchlass vorhandene Ladungsträgerplasma abgebaut wird. Schwerpunkt ist dabei die Untersuchung von zwei ungewollten Phänomenen, die während des Ausschaltens auftreten können. Diese sind ein plötzliches Abreißen des Rückstroms während der Kommutierung und eine Zerstörung der Diode mit einem lokalen Aufschmelzen in der aktiven Fläche. Betrachtet wird dazu der Ladungsträgerberg, der sich während des Schaltvorgangs bildet. Durch die Analyse des Verhaltens der Ladungsträgerbergfronten, lässt sich sowohl der Einfluss von Schaltbedingungen auf den Plasmaabbau als auch der Unterschied von anodenseitigen und kathodenseitigen Stromfilamenten erklären. Die Erkenntnisse werden auf das moderne Diodenkonzept CIBH (Controlled Injection of Backside Holes) angewandt. Das Potential von CIBH-Dioden zur Verbesserung der Höhenstrahlfestigkeit und Stoßstromfestigkeit wird aufgezeigt. Schließlich wird das neue Anodenemitterkonzept IDEE (Inverse Injection Dependency of Emitter Efficiency) vorgestellt, welches in Kombination mit CIBH die Gesamteigenschaften von Dioden maßgeblich verbessert. Die aktuelle Version Dissertation_Roman_Baburske_2011_11_21.pdf ist um einige Tippfehler bereinigt. / This work concerns the reverse-recovery process of bipolar power diodes. The focus is the investigation of two undesirable phenomena. These are the sudden strong reverse-current decay and the destruction of the diode with a local melting of the chip in the active area. The plasma layer, which arises during the switching period, is considered. An analysis of the plasma-layer front dynamics allows an understanding of the influence of switching parameters on the plasma extraction and the different behavior of anode-side and cathode-side filaments. The results of the analysis are used to describe the operation of the modern diode concept CIBH (Controlled Injection of Backside Holes). The potential of CIBH diodes to improve cosmic-ray stability and surge-current ruggedness is investigated. Finally, a new anode-emitter concept called IDEE (Inverse Injection Dependency of Emitter Efficiency) is introduced, which improves in combination with CIBH the overall performance of a power diode.

<p>This work focuses on the collection and analysis of Lithium-ion battery operational and temperature data during nail penetration testing through two different experimental approaches. Raman spectroscopy, machine learning, and internal temperature sensors are used to collect and analyze data to further investigate the effects on cell operation during and after nail penetrations, and the feasibility of using this data to predict future performance.</p> <p><br></p> <p>The first section of this work analyzes the effects on continued operation of a small Lithium-ion prismatic cell after nail penetration. Raman spectroscopy is used to examine the effects on the anode and cathode materials of cells that are cycled for different amounts of time after a nail puncture. Incremental capacity analysis is then used to corroborate the findings from the Raman analysis. The study finds that the operational capacity and lifetime of cells is greatly reduced due to the accelerated degradation caused by loss of material, uneven current distribution, and exposure to atmosphere. This leads into the study of using the magnitude and corresponding voltage of incremental capacity peaks after nail puncture to forecast the operation of damaged cells. A Gaussian process regression is used to predict discharge capacity of different cells that experience the same type of nail puncture. The results from this study show that the method is capable of making accurate predictions of cell discharge capacity even with the higher rate of variance in operation after nail puncture, showing the method of prediction has the potential to be implemented in devices such as battery management systems.</p> <p><br></p> <p>The second section of this work proposes a method of inserting temperature sensors into commercially-available cylindrical cells to directly obtain internal temperature readings. Characterization tests are used to determine the effect on the operability of the modified cells after the sensors are inserted, and lifetime cycle testing is implemented to determine the long-term effects on cell performance. The results show the sensor insertion causes a small reduction in operational performance, and lifetime cycle testing shows the cells can operate near their optimal output for approximately 100-150 cycles. Modified cells are then used to monitor internal temperatures during nail penetration tests and how the amount of aging affects the temperature response. The results show that more aging in a cell causes higher temperatures during nail puncture, as well as a larger difference between internal and external temperatures, due mostly to the larger contribution of Joule heating caused by increased internal resistance.</p>

Indiana University-Purdue University Indianapolis (IUPUI) / Lithium-ion batteries are widely used for portable electronics due to high energy density, mature processing technology and reduced cost. However, their applications are somewhat limited by safety concerns. The lithium-ion battery users will take risks in burn or explosion which results from some internal components failure. So, a practical method is required urgently to find out the failures in early time. In this thesis, a new method based on temperature difference between internal point and surface (TDIS) of the battery is developed to detect the thermal failure especially the thermal runaway in early time. A lumped simple thermal model of a lithium-ion battery is developed based on TDIS. Heat transfer coefficients and heat capacity are determined from simultaneous measurements of the surface temperature and the internal temperature in cyclic constant current charging/discharging test. A look-up table of heating power in lithium ion battery is developed based on the lumped model and cyclic charging/discharging experimental results in normal operating condition. A failure detector is also built based on TDIS and reference heating power curve from the look-up table to detect aberrant heating power and bad parameters in transfer function of the lumped model. The TDIS method and TDIS detector is validated to be effective in thermal runaway detection in a thermal runway experiment. In the validation of thermal runway test, the system can find the abnormal heat generation before thermal runaway happens by detecting both abnormal heating power generation and parameter change in transfer function of thermal model of lithium ion batteries. The result of validation is compatible with the expectation of detector design. A simple and applicable detector is developed for lithium ion battery catastrophic failure detection.