Laser-Induced Breakdown Spectroscopy of Laser-Structured Li(NiMnCo)O2 Electrodes for Lithium-Ion Batteries

Abstract

Cathode materials such as Li(NiMnCo)O2 (NMC) are presently under intense investigation regarding an improvement of lithium-ion cell cycling behavior by simultaneously providing reasonable material and manufacturing costs. Lithium-ion batteries require a further increase in cell life-time and a significant improvement in cycle stability for the use as energy storage system in high energy and high power applications such as for stationary devices and electric vehicles. Previous studies have shown that laser processing of three-dimensional (3D) micro-features in electrodes increases the active surface area and therefore the lithium-ion diffusion cell kinetics. Within this study, NMC cathodes were prepared by tape-casting and subsequent ultrafast laser-structuring. The capacity retention of lithium-ion cells with structured/unstructured NMC electrodes was measured by galvanostatic cycling at high charging/discharging currents. Furthermore, laser-induced breakdown spectroscopy (LIBS) was used for post-mortem analysis of lithium concentration in electrochemically cycled NMC cathodes based on calibration studies with electrodes at different State-of-Charges. LIBS was applied for electrochemically cycled NMC cathodes in order to investigate the degradation processes for different cell architectures (structured, unstructured). First results achieved from post-mortem studies using LIBS will be presented.