Improved electrochemical properties of patterned Si film electrodes

Cycle performance of patterned Si electrodes fabricated on flat and rough current collectors. [Display omitted] ► Influences of surface roughness of current collectors have been investigated in patterned Si film electrodes. ► An increase in roughness of current collect enhances adhesion with Si film. ► Rough electrode improves cycle performance of patterned Si electrode. ► High structural stability appears at rough electrode. Patterned Si films (electrodes) on flat and rough substrates were fabricated by masking with an expanded metal foil during film deposition. Their electrochemical properties and structural stability during charge–discharge process were examined and compared with each other. The patterned Si film fabricated on the rough substrate (rough electrode) exhibited the improved cycleability (91% of capacity retention after 100 cycles) and the enhanced structural stability compared to the patterned Si film fabricated on the flat substrate (flat electrode). After 50 cycles, some cracks were generated at Si tile in the flat electrode, whereas any structural damages were not observed at the rough electrode. The good electrochemical performance of the rough electrode was attributed to the space between Si tiles and the enhanced structural stability of electrode.