Thickness effect on the three-dimensional sculptured SiCu thin films used as negative electrodes in lithium ion batteries

SiCu (10 %at. Cu) composite three dimensional sculptured films with different thicknesses have been fabricated by an ion-assisted glancing angle co-deposition technique. The films have been evaluated as anodes considering morphological and structural differences depending on the different evaporation durations. The galvanostatic tests show that after 50^th cycles the thin film delivers 2124 mAh g^-1, but the thick electrode performs 685 mAh g^-1 as dicharge capacities. It is believed that the thin film electrode has a better electrochemical performance because increase in process time causes deformation in the helice's morphology, increase in ohmic resistance and generation of more stress in the electrode.