A spatially-microscopic-confined strategy to realize the completely reversible self-healing lattice restoration of MoS2 for ultrastable reversible sodium ion storage

On account of multiple electron exchange reaction process, transition metal sulfides with high specific capacities are considered as promising electrode materials for sodium-ion batteries. However, their poor electrical conductivity and fragile structure always result in poor cycling performance and low rate capability, which hinder their practical applications. Herein, based on a spatially-microscopic-confined “LEGO” strategy, double-layer carbon-encapsulated MoS2 (C@MoS2@C) nanocubes were synthesized by using nitrogen-doped hollow carbon nanocubes as precursor, and used as the anode materials. Due to the self-healing capacity of MoS2 during the charging process, microstructure of MoS2 was effectively restored and the electrode microstructure maintained stable under ultra-long-term cycling. With these synergistic effects, the C@MoS2@C anode exhibited a remarkable reversible capacity of 163.9 mA∙h∙g-1 after 10,000 cycles even at an ultrahigh current density (10 A∙g-1), with capacity fading as low as 0.004% per cycle. The current findings of spatially-microscopic-confined “LEGO” strategy could provide a promising way for rational design of high capacity electrodes.