ИСТИНА

The discharge capacity at galvanostatic cycling (C/8) of Si-O-Al electrodes was stable for no less than 100 cycles and was about 2800 mAh/g (1.1 mAh/cm2). During the multiple cycles of lithium insertion-extraction the composite thickness increases. Thickness growth happens unequally along the electrode surface. The total thickness of layered composites increases by 10-30-fold after 100-180 cycles. The elemental composition of Si-O-Al films changes during the cycling, specifically, fluorine and phosphorous appears at the surface and in the bulk of the composite. Simultaneously oxygen and carbon contents increase. This suggests the formation of passive film on the pillars’ surface, due to electrolyte reduction. Irregularity of thickness growth of Si-O-Al can be a consequence of non-uniform current density distribution, which can be related with different resistance in different areas.