Construction of Organic-Inorganic Solid Electrolyte Interphase by Gas-Liquid Plasma for High Performance Lithium Metal Anodes.

The construction of high-quality solid electrolyte interphase (SEI) on Li metal is one of the key strategies to improve the performance of Li metal anodes. Herein, we propose a novel gas-liquid hybrid source plasma technology to construct composite SEI consisting of organic lithium methyl carbonate (LMC) and inorganic lithium nitride (LiN) and lithium oxide (LiO) on the lithium metal. Supported by the theoretical calculation, the inorganic LiN and LiO phases possess low diffusion barrier potentials, favorable for fast Li transportation, and enhanced lithophilicity. Meanwhile, the organic LMC can effectively accommodate the volume expansion of lithium metal due to its high mechanical flexibility. Accordingly, the lithium metal anode modified by plasma-made SEI has a low overpotential of 11.4 mV at 1 mAh cm for 950 h with an average Coulombic efficiency of 99.7%, superior to the unmodified Li metal anode. When coupled with LiNiCoMnO (NCM811) cathode, the assembled full cell is proven with a higher capacity retention of 87.77% after 100 cycles at 0.5 C, indicating its significantly enhanced cycling stability due to the synergistic effect between LiN, LiO, and LMC in the composite SEI. This research demonstrates that plasma is a unique method for constructing high-quality SEI to achieve enhanced lithium anodes for energy storage.