Besides green energy harvest the storage of energy is one major problem in modern world. The state-of-the-art battery systems nearly reached their theoretical limit. Therefore new approaches are neccessary. Silicon electrodes for Li-batteries have a ten times higher gravimetric energy density than current graphite electrodes. Silicon is easily available and non-hazardous. Silicon electrodes can be used also in future battery systems such as lithium sulfur-cells. Their major drawback is the strong capacity fading. One reason is the massive volume expansion and the associated rupture of the solid electrolyte interface layer during lithiation. Therefore an artificial SEI-layer and the related aging shall be investigated using operando neutron reflectometry and electrochemical characterization. To gain insights in aging effects we want to investigate 10 cycles.