Carbon Atom Modulation of 2H-MoS2 Promotes Sodium Storage Kinetics by a Unique "Intercalation-Conversion" Mechanism

High theoretical capacity, stabilized and layered 2H phase molybdenum disulfide (2H) is regarded as a promising material for superior kinetics anode in sodium ion battery, but the inherent semiconducting properties and sluggish sodium ions diffusion limit the development of 2H based anode. Hence, this study builds a unique metalloid phase with high electronic conductivity and suitable layer structure by screening non-metallic carbon atoms doped in 2H (2H-C). As experimental and simulation results, 2H-C of metalloid properties after carbon atom modulation exhibit superior sodium storage kinetics and reversibility by a unique mechanism that promotes ion intercalation under high voltage window, and further good for the later uniformly conversion at lower voltage (intercalation-conversion mechanism). The 2H-C anode material delivers a remarkable reversible capacity of 156 mAh g(-1) at ultra-high 100.0 A g(-1), long-term life of 6000 cycles, and superior performance at low temperatures of -10 degrees C. Otherwise, 2H-C/Na3V2(PO4)(3) full cell also performs charge/discharge capacity of 80.0/76.7 mAh g(-1) with 87% capacity retention after 140 cycles at 0 degrees C. This discovery further explores the unique mechanism and application of 2D layered materials in sodium-ion battery anodes for fast kinetics under extreme conditions.