Sulfur Vacancies and 1T Phase-Rich MoS2 Nanosheets as an Artificial Solid Electrolyte Interphase for 400Wh 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||LiNi0.8 Co0.1 Mn0.1 O2 batteries demonstrate high-capacity retention of 93.5% and 92% after 1000 cycles and 300 cycles, respectively, at ultrahigh cathode loading of 20mg 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||LiNi0.8 Co0.1 Mn0.1 O2 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.