Lithiated metallic molybdenum disulfide nanosheets for high-performance lithium-sulfur batteries

Batteries based on redox chemistries that can store more energy than state-of-the-art lithium-ion systems will play an important role in enabling the energy transition to net zero carbon emissions. Lithium-sulfur (Li-S) batteries have shown extraordinary promise, where the electrically insulating sulfur must be loaded onto a conducting host. Here we report the use of pre-lithiated metallic 1T phase two-dimensional (2D) molybdenum disulfide (LixMoS2) as a sulfur host material for high-performance Li-S batteries under lean electrolyte conditions. The lithiation of conductive and lyophilic 1T phase MoS2 nanosheets leads to improved adsorption of lithium polysulfides, enhanced Li+ transport, accelerated electrochemical reaction kinetics and superior electrocatalytic activity for polysulfide conversion. These attributes enable pouch cell batteries to deliver energy density of 441 Wh kg(-1) and 735 Wh l(-1), together with capacity retention of 85.2% after 200 cycles. Our results provide insights into the design of practical Li-S cathodes based on electrocatalytically active and conducting 2D materials.