Sulfur Vacancies and 1T Phase-Rich MoS2 Nanosheets as an Artificial Solid Electrolyte Interphase for 400 Wh kg-1 Lithium Metal Batteries

Abstract

Constructing large-area artificial solid electrolyte interphase (SEI) to suppress Li dendrites growth and electrolyte consumption is essential for high-energy-density Li metal batteries (LMBs). Herein, chemically exfoliated ultrathin MoS₂ nanosheets (EMoS₂) as an artificial SEI are scalable transfer-printed on Li-anode (EMoS₂@Li). The EMoS₂ with a large amount of sulfur vacancies and 1T phase-rich acts as a lithiophilic interfacial ion-transport skin to reduce the Li nucleation overpotential and regulate Li⁺ flux. With favorable Young's modulus and homogeneous continuous layered structure, the proposed EMoS₂@Li effectively suppresses the growth of Li dendrites and repeat breaking/reforming of the SEI. As a result, the assembled EMoS₂@Li||LiFePO₄ and EMoS₂@Li||LiNi_0.8Co_0.1Mn_0.1O₂ batteries demonstrate high-capacity retention of 93.5% and 92% after 1000 cycles and 300 cycles, respectively, at ultrahigh cathode loading of 20 mg cm^-2. Ultrasonic transmission technology confirms the admirable ability of EMoS₂@Li to inhibit Li dendrites in practical pouch batteries. Remarkably, the Ah-class EMoS₂@Li||LiNi_0.8Co_0.1Mn_0.1O₂ pouch battery exhibits an energy density of 403 Wh kg^-1 over 100 cycles with the low negative/positive capacity ratio of 1.8 and electrolyte/capacity ratio of 2.1 g Ah^-1. The strategy of constructing an artificial SEI by sulfur vacancies-rich and 1T phase-rich ultrathin MoS₂ nanosheets provides new guidance to realize high-energy-density LMBs with long cycling stability.

Keywords: 1T phase; artificial solid electrolyte interphase; exfoliated MoS2; high‐energy density; lithium metal anodes; sulfur vacancies.