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

Abstract

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.