Surface Restraint Synthesis of an Organic-Inorganic Hybrid Layer for Dendrite-Free Lithium Metal Anode

Li metal is considered to be the most attractive anode for next-generation batteries because of its high specific capacity and low reduction potential. However, uncontrolled Li dendrite growth and low Coulombic efficiency cause severe capacity decay and safety issues. Here we propose a LiCl contained inorganic-organic hybrid layer on Li metal surface by a surface restraint dehalogenation reaction, which is highly uniform and features lithiophilic property as well as high ionic conductivity that can inhibit Li dendrite growth effectively. Consequently, the surface protected Li metal electrodes enable Li | Li symmetric cells to maintain a stable and low overpotential of 20 mV at a current density of 1 mA cm^-2 after cycling over 3000 h, and enable Li | LiFePO₄ pouch cell to decay only 0.05% in capacity per cycle at 5.0 C for 500 cycles, indicating excellent cycle stability and high rate capability. This work offers a simple and facile method to protect Li metal anode and promise a potential direction for industrialization of Li metal batteries.