Ion‐ and Electron‐Conductive Buffering Layer‐Modified Si Film for Use as a High‐Rate Long‐Term Lithium‐Ion Battery Anode

Abstract The rational design of electrochemically and mechanically stable Si anodes is of great importance for the development of high energy density lithium‐ion batteries. In this study, patterned Si‐based (Si/ZnO/C) trilayer composite films were synthesized by magnetron sputtering with the assistance of a patterned mask. The electron‐conductive C layer at the top of the composite film is deposited to enhance the interfacial stability between active film and electrolyte. The ion‐ and electron‐conductive Li 2 O–Zn middle layer can be ingeniously introduced by means of the poor reversed conversion reaction between ZnO and Li + ions after the first cycle. The resultant Si/Li 2 O–Zn/C trilayer composite film delivers a high reversible capacity of 1536 mAh g −1 after 800 cycles at a current density of 1.0 A g −1 and a long high‐rate cycling stability (1400 mAh g −1 after 6000 cycles even at a high current density of 10.0 A g −1 ). Excellent rate capability and improved Coulombic efficiency are also achieved. The influences of the patterned structure and each modified layer on the electrochemical properties are analyzed systematically. This work offers a new and promising direction to enhance the lithium‐storage properties of Si‐based thin‐film anodes.