Facile decoration of fluorinated metal-organic frameworks on copper foil for regulated lithium deposition and robust...

Lithium metal is one of the most promising anode materials for Li-ion batteries. However, lithium metal anodes suffer from low coulomb efficiency, short cycle life, and even serious safety issues, owing to the incompatible Cu/Li interface and brittle solid electrolyte interface (SEI). A facile strategy is proposed to construct stable lithium metal anodes by regulating both the Cu/Li interface and SEI membrane with a thin layer of copper-tetrafluoroterephthalate (CuTFBDC), which can guide the uniform lithium deposition and the LiF-rich SEI. The prepared CuTFBDC@Cu foils can be applied as current collectors, and the assembled Li@CuTFBDC@Cu//Li symmetric cell exhibits a stable performance at a current density of 0.5 mA cm^-2 for more than 3000 h, with a small voltage hysteresis of less than 11.5 mV, surpassing that of the bare Cu foil. The assembled Li@CuTFBDC@Cu//LFP (LiFePO₄) full cell proceeds smoothly for 200 cycles at a current density of 2 C with a specific capacity of 133.8 mAh/g, and the capacity can be maintained at 125.29 mAh/g after 250 cycles. This facile strategy can provide a solution for both the Cu/Li interface and SEI membrane, showing an excellent prospect for practical applications in lithium metal batteries.