Sweetening Lithium Metal Interface by High Surface and Adhesive Energy Coating of Crystalline α-d-Glucose Film to Inhibit Dendrite Growth

The notorious growth of lithium (Li) dendrites and the instability of the solid electrolyte interface (SEI) during cycling make Li metal anodes unsuitable for use in commercial Li-ion batteries. Herein, the use of simple sugar coating (α-d-glucose) is demonstrated on top of Li metal to halt the growth of Li dendrites and stabilize the SEI. The α-d-glucose layer possesses high surface and adhesive energies toward Li, which promote the homogenous stripping and plating of Li ions on top of the Li metal. Density functional theory reveals that Li-ion diffusion within the α-d-glucose layer is governed by hopping around the bare sides of the O atoms and along the apparent passages formed by the glucose molecules. Stable cycling performance is achieved when combining α-d-glucose–coated Li (G|Li) anodes with sulfur- and LiFePO₄-based cathodes in both LiTFSI (ether) and LiPF₆ (carbonate) electrolyte systems. A G|Li–based symmetrical cell operates at a current density of 1 mA cm⁻² and areal capacity of 1 mAh cm⁻² displays a stable overpotential profile for over 9 months (7000 h) of continuous charge/discharge cycling.