Au-embedded mesoporous molecular sieve enables robust organic/inorganic hybrid solid electrolyte interphase for high-performance lithium metal batteries

The solid electrolyte interphase (SEI) determines the lithium (Li) deposition behavior for long-term lithium metal batteries. However, the naturally formed fragile SEI would cause the nonuniform lithium deposition and random dendrite growth due to weak interaction of the heterogeneous distributed inorganic and organic species. Herein, we designed Au-embedded mesoporous molecular sieve as an electrolyte modifier to feasibly form a robust organic/inorganic hybrid SEI. Such hybrid SEIs, composed of Si-O interlinked polycarbonates (poly(CO3)) which is derived from the Au-induced electrocatalytic polymerization of EC (ethylene carbonate), possess an ultrahigh Young's modulus of 11.6 GPa, achieving uniform lithium deposition and suppression of lithium dendrites. Assembled by the Au@MCM-41-modified electrolyte, the Li||Li symmetrical cells exhibit a recyclable behavior of Li deposition/dissolution over 900 h at 0.5 mA cm−2, and the Li||LFP (LiFePO4) full cells maintain a high capacity of 123 mAh g−1 even after 300 cycles at 1.0 C. This work explores a new route to in situ develop a robust and effective SEI for prospective lithium metal batteries in practical application and social requirement.