External and internal Cultivation: Design for Mo-doped SnS2/SnO2 heterostructure on N-doped graphene achieves Kinetics-Enhanced and Superior-Lithium storage performance

Abstract

In this work, the Mo-doped SnS2/SnO2 with N-doped graphene (Mo-SnS2/SnO2/NG) composites were composited by a simple one-step hydrothermal method. This hybrid material is of supreme importance to improving the charge storage kinetics and practicality of tin-based materials from the inside out. The density functional theory (DFT) calculations revealed the Mo-doped SnS2/SnO2 heterojunction interface is more favorable for charge transport and interfacial reaction kinetics than pure SnO2 and SnS2, and the coupling between heterojunctions can alleviate the drawbacks of individual building blocks, thereby enhancing the Li+ storage capacity. Furthermore, Mo-SnS2/SnO2 quantum dots (2.5–4.5 nm) with nanoscale morphology can effectively shorten the Li+ diffusion path and mitigate the volume change, while the N-doped graphene (NG) substrate can provide superior electrical conductivity and stability. As a result, as an anode material for Li+ batteries, it has initial coulombic efficiency of close to 80 % and can maintain the excellent performance of 2052.4 mAh g-1 for 100 cycles at 0.1 A g-1. This work suggests that Mo-SnS2/SnO2/NG nanohybrid materials will have great potential as an anode material for lithium-ion batteries.