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

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 MoS nanosheets (EMoS) as an artificial SEI are scalable transfer-printed on Li-anode (EMoS@Li). The EMoS 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 EMoS@Li effectively suppresses the growth of Li dendrites and repeat breaking/reforming of the SEI. As a result, the assembled EMoS@Li||LiFePO and EMoS@Li||LiNiCoMnO 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. Ultrasonic transmission technology confirms the admirable ability of EMoS@Li to inhibit Li dendrites in practical pouch batteries. Remarkably, the Ah-class EMoS@Li||LiNiCoMnO pouch battery exhibits an energy density of 403 Wh kg over 100 cycles with the low negative/positive capacity ratio of 1.8 and electrolyte/capacity ratio of 2.1 g Ah. The strategy of constructing an artificial SEI by sulfur vacancies-rich and 1T phase-rich ultrathin MoS nanosheets provides new guidance to realize high-energy-density LMBs with long cycling stability.