Building Fast Diffusion Channel by Constructing Metal Sulfide/Metal Selenide Heterostructures for High-Performance Sodium Ion Batteries Anode

Heterostructure engineering is one of the most promising modification strategies toward improving sluggish kinetics for the anode of sodium ion batteries (SIBs). Herein, we report a systemic investigation on the different types of heterostructure interfaces’ effects of discharging products (Na 2 O, Na 2 S, Na 2 Se) on the rate performance. First-principle calculations reveal that the Na 2 S/Na 2 Se interface possesses the lowest diffusion energy barrier (0.39 eV) of Na among three kinds of interface structures (Na 2 O/Na 2 S, Na 2 O/Na 2 Se, and Na 2 S/Na 2 Se) due to its smallest recorded interface deformation, similar electronegativity, and lattice constant. The experimental evidence confirms that the metal sulfide/metal selenide (SnS/SnSe 2 ) hierarchical anode exhibits outstanding rate performance, where the normalized capacity at 10 A g –1 compared to 0.1 A g –1 is 45.6%. The proposed design strategy in this work is helpful to design high rate performance anodes for advanced battery systems.