Large‐Area Lithium Electroplating on Copper Foil

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.