SnS/N-Doped carbon composites with enhanced Li+ storage and lifetime by controlled hierarchical submicron- and nano-structuring†
Hollow and dense SnS sub-microspheres constructed from self-assembled nanosheets wrapped in a nitrogen-doped carbon shell were prepared by a low-cost, facile solvothermal process followed by annealing. The lithium-ion storage capacities of the hollow and dense spheres were tested and compared as anodes in lithium-ion battery half cells. The hollow microspheres showed low internal charge transfer resistance, good buffering of volume changes during lithiation and delithiation and good rate and cycling performance. After 1000 cycles, the hollow SnS composite still delivered a capacity of 420 mA h g−1 at 1.0 A g−1, which is 2.5 times higher than that of the dense spheres. The capacity retention from the second cycle on was 84% and 75%, respectively. The superior lithium storage performance of the hollow particles arise from their pronounced porosity, hierarchical architecture from the self-assembled nanosheets and well-controlled uniform carbon shells.