Robust 3D macroporous structures with SnS nanoparticles decorating nitrogen-doped carbon nanosheet networks for high performance sodium-ion batteries

Abstract

There still remains a great technological challenge for the development of advanced rechargeable batteries for future electric vehicles and for storage for a more renewable energy grid. In this paper a reliable and simple method for the preparation of three-dimensional (3D) hierarchical nanohybrids with tin sulfide (SnS) nanoparticles decorating nitrogen-doped carbon nanosheet networks (SnS/N-CNNs) as an anode material for SIBs is reported. The interconnected network structure, associated with its unique porous feature, endows the developed SnS/N-CNNs with enough straining space for mitigating the effect of volume expansion upon cycling, and also ensures highly favorable transport kinetics for both electrons and sodium ions. Accordingly, the SnS/N-CNNs exhibit an outstanding electrochemical performance with a high capacity and long-term cycling performance at a high mass loading, delivering high reversible capacity of 484 and 322 mA h g⁻¹ at the current rate of 1.0 and 5.0 A g⁻¹, respectively, for 1000 cycles, running at a mass loading of 1.5 mg cm⁻². Capacities of 428 and 331 mA h g⁻¹ were obtained at the current densities of 1 A g⁻¹ at 2.8 and 4.3 mg cm⁻² loading, respectively. The first principles theoretical calculations indicated that robust binding between SnS and nitrogen-doped CNNs was of great significance for maintaining the 3D network structure that achieves high capacity, high rate capability, and superior long cyclic stability even at a high mass loading.