Large-Area Lithium Electroplating on Copper Foil

Abstract

Anode-free lithium metal batteries have attracted much attention due to their high energy density and lack of excess Li. In this work, Li film is deposited on large-area copper foil (64 cm²) with good uniformity by a self-designed electroplating device that quickly assembles and can be operated outside the glove box. By adding the high concentration of LiNO₃ into the lithium bis(trifluoromethylsulfonyl)azanide (LiTFSI)-based electrolyte, the high Li⁺ conductive solid electrolyte interface (SEI) layer regulated the Li⁺ flux, forming the columnar structure at a high current density of 40 mA cm⁻², and compact morphology at 60 mA cm⁻². Even at 100 mA cm⁻², Li film on copper foil (Li@Cu) maintains its macroscopic uniformity. Furthermore, electrolytes, additives, and temperature are further optimized. The symmetric Li@Cu || Li cell cycle life can extend to 80 cycles. This work provides essential information for future manufacturing processes and scale-up.