Highly stable and dendrite-free lithium metal batteries enabled by a novel artificial interphase layer
Lithium metal batteries (LMBs) face critical barriers of inferior cycling stability and safety hazards from uncontrolled lithium dendrite growth. This study constructs a multifunctional hybrid protection layer of Li3Bi/LiF via spontaneous reduction between Li and BiF3. The lithiophilic Li3Bi serves as nucleation seeds to reduce the nucleation barrier and guide uniform Li deposition, while LiF with high ionic conductivity promotes Li+ diffusion kinetics and homogenizes Li+ flux during plating/stripping. The BiF3-Li symmetric cell exhibits excellent Li plating/stripping behavior over 2500 h at 3 mA cm−2 for 3 mAh cm−2 with a low voltage hysteresis of 60 mV. The BiF3-Li||LiFePO4 full cell demonstrates a remarkable capacity retention of 73% after 1700 cycles at 1 C. This work provides a facile strategy for developing multifunctional artificial interlayers and offers valuable insights for the design and fabrication of high-performance LMBs.