Lithium-Ion Battery—3D Micro-/Nano-Structuring, Modification and Characterization

Abstract

Laser processing technologies for micro-/nanostructuring of electrode materials have a great potential in improving the electrochemical performance and operational lifetime of lithium-ion cells. Different types of laser structuring were used on different surfaces such as metallic current collectors and thin or thick film electrodes. For thin metallic current collector foils, at anode and cathode sides, the self-organized structuring by laser-induced periodical surface structures and laser interference methods were successfully applied for improving electrode film adhesion and cell impedance. For thin and thick film electrode layers direct laser ablation with structure sizes down to the micrometer range and high aspect ratios were found most powerful in order to create three-dimensional (3D) cell architectures with benefits regarding cell performance and a homogenous wetting of composite electrodes with liquid electrolyte. A huge impact of laser formed 3D batteries regarding capacity retention and cell lifetime at high charging and discharging rates was detected. The impact on diffusion kinetics of laser structured 3D electrodes was studied using classical methods such galvanostatic intermittent titration technique and cyclic voltammetry. A further improvement of 3D battery performance due to an operation in high potential regime and for advanced high energy silicon anode material was achieved by joining of laser structuring and thin-film passivation either of active particles before laser patterning or by passivating of complete 3D electrodes after laser processing. Finally, laser-induced breakdown spectroscopy will be presented as a powerful tool for elemental mapping of entire 2D and 3D electrodes. The impact of 3D architectures on lithium distribution and chemical degradation processes in 2D batteries was investigated and analyzed.