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.