Micromechanical examination of ageing effects in lithium-ion battery materials
Nanoindentation, simulation and SEM-based operando observation

Battery materials are repeatedly loaded by mechanical stresses during charge/discharge cycles which results in a multitude of ageing phenomena one of which is cracking. The degradation in terms of the mechanical properties of the material is quantified by statistical and targeted nanoindentation and the underlying mechanisms are analysed using SEM-based methods such as real-time observation of the electrode microstructure changes or comparative STEM examinations of pristine and cycled electrodes. A novel combination of a heat treatment and nanoindentation is used to evaluate different degradation mechanisms separately. The experimental work is supported by a coupled chemo-mechanical finite element simulation model.