Synergistic Dual-Additive Electrolyte Enables Practical Lithium-Metal Batteries.

Abstract

A rechargeable Li metal anode coupled with a high-voltage cathode is a promising approach to high-energy-density batteries exceeding 300 Wh kg-1 . Reported here is an advanced dual-additive electrolyte containing a unique solvation structure and it comprises a tris(pentafluorophenyl)borane additive and LiNO3 in a carbonate-based electrolyte. This system generates a robust outer Li2 O solid electrolyte interface and F- and B-containing conformal cathode electrolyte interphase. The resulting stable ion transport kinetics enables excellent cycling of Li/LiNi0.8 Mn0.1 Co0.1 O2 for 140 cycles with 80 % capacity retention under highly challenging conditions (≈295.1 Wh kg-1 at cell-level). The electrolyte also exhibits high cycling stability for a 4.6 V LiCoO2 (160 cycles with 89.8 % capacity retention) cathode and 4.95 V LiNi0.5 Mn1.5 O4 cathode.