N‐Type Doped Silicon Thin Film on a Porous Cu Current Collector as the Negative Electrode for Li‐Ion Batteries

This work reports the preparation of a three‐dimensional Si thin film negative electrode employing a porous Cu current collector. A previously reported copper etching procedure was modified to develop the porous structures inside a 9 μm thick copper foil. Magnetron sputtering was used for the deposition of an n‐type doped 400 nm thick amorphous Si thin film. Electrochemical cycling of the prepared anode confirmed the effectiveness of utilizing the approach. The designed Si thin film electrode retained a capacity of around 67 μAh cm(−2) (1675 mAh g(−1)) in 100(th) cycle. The improved electrochemical performance resulted in an enhancement of both areal capacity and capacity retention in contrast with flat and rough current collectors that were prepared for comparison.