High-performances of Li4Ti5O12 anodes for lithium-ion batteries via modifying the Cu current collector through magnetron sputtering amorphous carbon

Abstract Interface performances between the electroactive materials and current collector plays a significant role in lithium-ion batteries. However, up to now, rare studies have focused on reducing the contact resistance of the interface by optimizing the interfacial properties between the electroactive materials and current collector. In this work, the internal resistance is significantly reduced by the amorphous carbon film onto copper current collector (C–Cu) deposited via magnetron sputtering, which can significantly improve Li storage performances of Li4Ti5O12 (LTO) anode. The Li4Ti5O12 cell using C–Cu current collector has a superior capacity (162.51 mAh g−1) at 1C, which is 24.74% higher than that of using pure copper foil. The C–Cu-LTO cell has a capacity retention of up to 96.68% after charging/discharging at 1C for 400 cycles. X-ray photoelectron spectroscopy (XPS) analysis confirms that this amorphous carbon film acts as the protective film for the C–Cu current collector, effectively preventing the copper foil from being oxidized, thereby improving the chemical stability of the C–Cu current collector and prolonging the cycle life of cell. In view of the validity and mass productivity of magnetron sputtering, this study highlights the potential route for industrial preparation of C–Cu.