Hybridization of Sulfur-Defective MoS₂ and Holey Expanded Graphite for a Long Cycling Lithium Oxygen Battery Cathode

The development of MoS₂ as a cathode electrocatalyst for lithium-oxygen batteries (LOBs) has attracted considerable attention due to its natural abundance, excellent catalytic activity, and chemical stability. However, the sluggish and complicated kinetic of insulating and bulk discharge products on the electrode surface is one of major factors for MoS₂ as a cathode for high performance LOBs. Defect engineering of an electrocatalyst and its hybridization with highly conductive frameworks are effective strategies to address this critical issue. Herein, we report a hybrid of rich sulfur-defective MoS₂ (MoS_2-) nanosheets grown on highly conductive holey expanded graphite (hEG) with well-defined "worm-like" and holey structures (MoS_2-/hEG). Benefiting from rich sulfur defects of MoS_2- and the highly conductive nature and holey structures of hEG, the MoS_2-/hEG hybrid as a cathode for LOBs displays outstanding electrochemical performance with an extremely high discharge capacity of 19000.3 mAh g^-1 at 500 mA g^-1 and an ultralong cycling life of over 500 cycles at 1000 mA g^-1 with a controlled specific capacity of 1000 mAh g^-1.