Uniform Fast-Kinetic Anode/Cathode Electrolyte Interphases Enable High Performance 3C Li-Metal Batteries with > 99.9% Coulombic Efficiencies

Lithium metal batteries (LMBs) represent one of the most promising energy storage systems due to unparalleled energy density. However, in commercial electrolytes, their practical high-power performance is still hampered by unstable electrolyte interfaces, leading to severe anode dendrite growth and cathode degradation. Here, 4-fluoro-3-nitrophenylboronic acid is introduced as a dual-function additive, contributing to uniform N-/F-rich interphase layers at both electrodes of the LMBs. Therefore, in the optimized electrolyte, Li-metal electrodes demonstrate enhanced plating/stripping reversibility of > 700 h (vs. 250 h at 1 mA cm^-2 and 0.5 mAh cm^-2) and coulombic efficiency of 98.2% (vs. 84.2%). Moreover, the corresponding LMBs achieve 99.9% capacity retention (vs. 44.7%) after 500 cycles at 3C rate, simultaneously maintaining > 99.9% coulombic efficiencies. The impressive fast-charging performance attributes to not only the uniform and compact Li deposition at the anode, but also the inhibited uncontrolled electrolyte decomposition and active species loss at the cathode due to the robust electrolyte interphases. This work highlights that proper electrolyte additive is crucial for fast-charging metal batteries.