Coupled interfacial desolvation regulation and LiF-Rich SEI for fast-charging lithium metal batteries in carbonate electrolytes

Lithium metal anode is considered as the most promising candidates for next-generation batteries due to its high specific energy. However, fast charging of lithium metal batteries in widely used carbonate electrolytes remains highly challenging, as insufficient interfacial desolvation and non-ideal solid electrolyte interphase (SEI) formation compromise lithium deposition uniformity. Here, we demonstrate that fast-charging lithium metal batteries can be enabled through a coupled regulation of interfacial desolvation behavior and LiF-rich SEI formation, achieved by introducing a stable molecular layer at the lithium surface without altering the bulk electrolyte composition for high Li⁺ conductivity. Consequently, during the fast-charging process, lithium metal maintains the spherical morphology of deposition, even at the ultra-high current density of 6 mA cm−2. And the dense dendrite-free lithium growth can still retain under the ultra-high deposition capacity of 100 mAh cm−2. The assembled Li||LFP full cell delivers high capacity retention of 85% after 3000 cycles under ultra-high rate of 20 C. This work offers insights on unlocking the fast-charging potential of lithium metal batteries in high-rate applications.