Sulfur-Deficient Porous SnS Microflowers as Superior Anode for Alkaline Ion Batteries.

SnS as a high energy anode material has attracted extensive research interest recently. However, the fast capacity decay and low rate performance in alkaline-ion batteries associated with repeated volume variation and low electrical conductivity plague them from practical application. Herein, we propose a facile method to solve this problem by synthesizing porous SnS microflowers with in-situ formed sulfur vacancies. The flexible porous nanosheets in the three-dimensional flower-like nanostructure provide facile strain relaxation to avoid stress concentration during the volume changes. Rich sulfur vacancies and porous structure enable the fast and efficient electron transport. The porous SnS microflowers exhibit outstanding performance for lithium ion battery in terms of high capacity (1375 mAh g at 100 mA g) and outstanding rate capability (827 mA h g at high rate of 2 A g). For sodium ion battery, a high capacity (~522 mAh g) can be achieved at 5 A g after 200 cycles for SnS microflowers. The rational design in nanostructures, as well as the chemical compositions, might create new opportunities in designing the new architecture for highly efficient energy storage devices.