Paul Titscher

This work focuses on the deposition mechanism of zinc within nonstirred alkaline cells. A zinc anode based on zinc particles and a 3D copper foam is examined with X‐ray micro tomography to visualize its structural changes after discharging and recharging. To this end, zinc and zinc oxide components of the anode are distinguished in the tomography images, and a 3D model is reconstructed to investigate zinc deposition. The results contribute to the general understanding of structural changes during cycling to develop new concepts to stabilize the zinc anode and enhance the performance of zinc–air batteries.

The use of a high‐intensive ring shear mixing system to produce the composite materials from carbon black and sulfur for cathodes in lithium–sulfur batteries is described. The examined process is evaluated concerning its stress mechanism and its influence on the properties of the resulting composite materials. The architecture of the composites can be described as a core–shell structure, whose size and strength depend on the expended stress input from the mixing process. The comparison of electrodes from these composite particles with a reference cathode based on pure carbon black proves an increase in the energy density of approximately 30%. Furthermore, using the composite particles, a higher amount of additional carbon black enables an increase in the specific capacity of approximately 25% due to the improvement of the mechanical properties of the coating.

Primary zinc–air batteries are well established in the commercial market, but secondary zinc–air batteries still suffer from challenging problems. Multiple charge and discharge cycles result in zinc density migration and the formation of passivating by-products, which can ultimately change the shape of the zinc anode. This work focuses on the use of zinc particles in combination with highly structured current collectors in a cell with a stagnant alkaline electrolyte. Copper weave and copper foam were used as current collectors. The influences of the zinc particle size, the mass loading and the macroscopic structure of the anodes were characterized. Highly structured electrode designs led to improved discharge and cycling performances. Due to the increased active surface area, the electrodes take advantage of highly distributed zinc deposits. The results reveal that the use of multiscale structures within the zinc anode can be beneficial for further applications.

Lithium–sulfur batteries are nearly ready to be commercialized. However, each material composition has specific challenges regarding its adaption to state of the art production lines of lithium‐ion batteries. The influence of the dispersing and calendering process on the battery performance is investigated with an easy‐to‐implement material approach and a solvent‐based process. The slurry is treated by different dispersing intensities using an extruder and a triple roller mill, which leads to increased energy densities. The coating is calendered to increase the energy density by maintaining the specific capacity. The reactions within the sulfur cathodes are investigated by evaluating the potentials of the upper and lower voltage plateaus. It was determined that the variation of the process parameters leads to a changed reactivity of the polysulfide reactions but not to a shift of the sulfur utilization within the sulfur cathodes. The process parameters influence the pore structure of the cathode, resulting in different sensitivities for higher C‐rates.

The quest towards increasing the energy density of traction battery technologies has led to the emergence and diversification of battery materials. The lithium sulfur battery (LSB) is in this regard a promising material for batteries due to its specific energy. However, due to its low volumetric energy density, the LSB faces challenges in mobility applications such as electric vehicles but also other transportation modes. To understand the potential environmental implication of LSB batteries, a comparative Life Cycle Assessment (LCA) was performed. For this study, electrodes for both an NMC111 with an anode graphite and a LSB battery cell with a lithium metal foil as anode were manufactured. Data from disassembly experiments performed on a real battery system for a mid-size passenger vehicle were used to build the required life cycle inventory. The energy consumption during the use phase was calculated using a simulative approach. A set of thirteen impact categories was evaluated and characterized with the ReCiPe methodology. The results of the LCA in this study allow identification of the main sources of environmental problems as well as possible strategies to improve the environmental impact of LSB batteries. In this regard, the high requirements of N-Methyl-2-pyrrolidone (NMP) for the processing of the sulfur cathode and the thickness of the lithium foil were identified as the most important drivers. We make recommendations for necessary further research in order to broaden the understanding concerning the potential environmental implication of the implementation of LSB batteries for mobility applications.