Rational Design of Bimetal-Organic Framework-Derived ZnSnS3 Nanodots Incorporated into the Nitrogen-Doped Graphene Framework for Advanced Lithium Storage

Owing to their abundant resources and high theoretical capacities, nanostructured metal sulfides exhibit attractive potential to be used as anode materials for lithium-ion batteries. However, engineering complex metal sulfide nanostructures is still an urgent challenge to achieve advanced performance, enhancing the electrical conductivity and maintaining the structural integrity. Herein, a facile and novel strategy is rationally designed to fabricate ZnSnS3 nanodots directly derived from bimetal (Sn/Zn)-organic frameworks, which are encapsulated into the interconnected three-dimensional N-doped graphene framework (denoted as ZnSnS3@NG). In this hierarchical architecture ZnSnS3@NG, the synergistic effect of high-capacity ZnSnS3 and the superior-conductive graphene network provides a stable structural framework to restrain the structure pulverization without agglomeration and shortens the charge transport pathways simultaneously, significantly enhancing the Li+-storage capability. As expected, the ZnSnS3@NG composite can deliver an excellent reversible capacity of 1354 mA h g(-1) at 1 A g(-1). Meanwhile, it obtains a high reversible capacity of 516.5 mA h g(-1) after 1500 long cycles at an ultrahigh rate of 5 A g(-1), with capacity retention as high as 98.55%. This well-designed strategy can pave a way for rational construction of bimetallic sulfides with excellent performance in energy-storage area.