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Safety is a universal concern for all products, their production, their use, and the handling of incidents. Several general methodologies have been developed to qualitatively and quatitatively assess the risks. Some of these have been written into law, others are standards applicable to special classes of products or guidelines issued by professional associations. They represent the state-of-the art that has to be taken into account by all parties involved to assure safety at all stages of the life of a product. The nature of risks emanating from batteries are electrical, chemical, thermal, and mechanical. In this book, these risks are examined for batteries with aqueous electrolytes like lead acid, for lithium primary and lithium-ion rechargeable batteries with a focus on the latter. Starting from the nature of risks of batteries to recycling of battery materials, safety is discussed in general terms and reference is made to the chapters in this book which deal with these topics.

To minimize the risks for the user of the Li battery, safety devices are installed at all system levels. Battery powered devices are safe as long the operator obeys by certain rules. First, he should follow the manufacturer’s instructions. He must not operate the batteries outside of the defined operating window, which in most cases is determined and controlled by the BMS. The battery or the device must not be modified by users. The same applies to repairing a battery. If safety devices have shut down the battery, the battery functionality must not be restored, e.g., by defeating safety devices. The user must observe the regulations for transport and disposal. Stakeholders along the battery value chain, such as distributors, repair and maintenance shops, and recyclers, also need to manage the risks associated with their special tasks, which are often dependent also of the application (consumer, EV, stationary storage). They also must follow all applicable regulations.

Lithium batteries can be classified by the anode material (lithium metal, intercalated lithium) and the electrolyte system (liquid, polymer). Rechargeable lithium-ion batteries (secondary cells) containing an intercalation negative electrode) should not be confused with nonrechargeable lithium primary batteries (containing metallic lithium). The superior performance of lithium-ion batteries has made them the main power source for portable applications. They also offer attractive performance advantages for both automotive and standby power applications. Efforts to develop secondary cells with lithium metal anodes have shown problems of stability and safety.

Due to ever-growing energy requirements, the world’s population is dependent on fossil energy sources, which will result in a shortage of these resources and possible climate changes. It is widely recognized that energy production increasingly needs to be covered by renewable energy sources. This trend has been fueled by the rapid economic growth of the so-called emerging countries and the decision by some industrial nations to phase out nuclear energy production. The increased use of renewable energies, such as solar and wind power, has ultimately resulted in the necessity to store electric power temporarily in order to bridge the gap between the time of producing energy and consuming it. Batteries can provide part of the required capacity, ranging from battery units for homes with several kWh of storage capacity through to large batteries with capacities in the MWh range suitable as grid storage systems. Other systems such as pump storage systems or compressed-air storage systems already exist, but can only be expanded to a limited extent because they require a specific geographical environment. In addition, other electrochemical storage systems are currently being applied or developed in the stationary battery system segment such as high-temperature batteries and redox-flow systems.

Die Abhangigkeit der Versorgung des stets wachsenden Energiebedarfs der Weltbevolkerung von fossilen Energietragern wird zu einer Verknappung derselben fuhren und zu moglichen Veranderungen des Klimas beitragen. Es wird allgemein anerkannt, dass die Energieerzeugung immer starker durch erneuerbare Quellen abgedeckt werden muss. Dieser Trend wird durch das rapide Wirtschaftswachstum der sogenannten Schwellenlander sowie den geplanten Ausstieg einiger Industriestaaten aus der Atomenergieerzeugung noch beschleunigt. Die verstarkte Nutzung erneuerbarer Energiequellen wie Solar- und Windenergie fuhrt letztendlich zu der Notwendigkeit, die so erzeugte elektrische Energie zwischenzuspeichern, um die zeitliche Verschiebung zwischen Energieerzeugung und Bedarf auszugleichen. Batterien bis in den MWh-Bereich konnen einen Teil der benotigten Speicherkapazitaten schaffen. Andere Systeme wie Pumpspeicherkraftwerke oder Druckluftspeicher existieren bereits, konnen aber nur beschrankt ausgebaut werden, da sie an gewisse geographische Gegebenheiten gebunden sind. Im Bereich der stationaren Batteriesysteme sind noch andere elektrochemische Speicher wie Hochtemperaturbatterien und Redox-Flow-Systeme in der Anwendung bzw. Entwicklung.

In order to find a wide range of applications using a new cell chemistry, many different factors such as cell voltage, energy density, power density, safety, reliability, life, cost and environmental impact have to be considered. The lithium-ion or SWING system demonstrated a specific energy of more than 100 Wh/kg in small cells and more than 80 Wh/kg in large cells with an approximately 100 Wh energy centent, and a cycle life of more than 1000 cycles in cells with LiCoO2 cathodes. When a manganese oxide-based cathode was used it has furthermore the potential to become a low cost system without the use of heavy metals.

1,3-Aryl migrations of title compounds (2) are shown to be triggered by base catalysis under mild conditions. Alternative rearrangement conditions, limiting factors, as well as the occurrence of byproducts, and competing products are investigated. A crossover experiment reveals the purely intramolecular nature of the Chapman-type rearrangement. The structure of the rearrangement product 1-(2,6-dichlorophenyl)-2-(2-methylallylimino)hexahydro-1,3-diazepine (3a) is confirmed by X-ray analysis. An explanation for the directionality of the reaction is furnished by an MNDO calculation on the reaction enthalpy.

The matrix power series expansion is used for deriving the static geometric stiffness and elastic stiffness matrix of a hybrid displacement model. No restrictions about the number of interpolation functions within the interior of the element are introduced. The generalized degrees-of-freedom are not defined on nodal points but in an abstract way on element boundaries. Plate bending problems are considered to demonstrate the method.

Based on a generalized complementary energy principle the derivation of the element matrices is presented for calculation of natural frequencies. The degrees-of-freedom are not defined on nodal points but in an abstract way. No restrictions about the number of interpolation functions in the interior and at the boundaries of the element have been introduced. The exact solution of the discretized element equations leads to the dynamic stiffness matrix while the approximate solution results in a linear eigenvalue problem. Plate bending problems are used to study the convergence of frequencies depending on the degrees of interpolation functions within the element and on its boundaries and on the number of elements.

The excitations connected with quantum condensation of a fermion gas are calculated quantitatively along the lines of a previous paper. We find exact agreement with earlier results: excitations of the phonon type in the absence of Coulomb interaction, strong indications for their nonexistence in the presence of this interaction.