Organic Eutectic Mixture Incorporated with Graphene Oxide Sheets as Lithiophilic Artificial Protective Layer for Dendrite-Free Lithium Metal Batteries

摘要

For wide and safe applications of Li metal batteries, the suppression of Lidendrite growth during cycling is the most crucial yet challenging topic.In this work, an artificial protective interlayer of GO-BQ@LiTFSI (GBL) isdesigned to overcome this issue. The GBL interlayer is prepared by incorporatinggraphene-oxide sheets with a liquid organic eutectic mixture of1,4-benzoquinone and bis (trifluoromethane) sulfonamide lithium salt.With the exceptional merits of these functional materials, the incorporationendows the GBL interlayer with rich lithiophilic active sites, good ionicconductivity, superior thermal stability and compatibility with the electrolyte,and the precursor supply stations for the formation of a compact and LiF-richsolid-electrolyte interface (SEI). Consequently, the GBL effectively promotesthe uniform nucleation of Li at low over-potentials and regulates the Li-ionflux, leading to the formation of planar Li metal. After utilizing the GBLinterlayer in the Li‖Li symmetric cells, high electrochemical stability for 600 his achieved at a current density of 3 mA cm~(?2) and a capacity of 3 mAh cm~(?2).Remarkably, this modification enables Li‖LiFePO_4 full cells with 1600 cyclesat 1C and a high-capacity retention of 95.23 with a cathode mass loadingof ≈6 mg cm~(?2).