Abstract:
Molybdenum disulfide (MoS
2) and tin disulfide (SnS
2), known for their high theoretical capacities and large interlayer spacings, have been widely used as anode materials in lithium-ion batteries. The composite materials formed between them are an even greater research focus. However, conventional MoS
2/SnS
2 composites suffer from severe volume changes and structural fragmentation during the charge–discharge cycles, leading to rapid decay in specific capacity, which hinders the cycling stability that MoS
2/SnS
2 composite electrodes should ideally possess. In this work, a novel MoS
2/PDA/SnS
2 nanotube was designed and synthesized. Specifically, a hollow MoS
2 nanotube was coated with a polydopamine (PDA) layer as a confinement structure to prevent the structural breakdown of MoS
2 in subsequent processes. Subsequently, MoS
2/PDA/SnS
2 nanotubes were successfully prepared by growing a layer of SnS
2 nanosheets on the polydopamine (PDA) surface through a hydrothermal method. This preparation method not only prevented the rupture of the hollow tubular structure but also facilitated the growth of SnS
2 nanosheets through the free dopamine molecules. This superior structural design significantly enhances the stability of the material while also improving its electrical conductivity. The composite electrode demonstrates excellent cyclability, retaining a specific discharge capacity of 1330.2 mAhg
−1 over 90 cycles at 0.1 A g
−1. Notably, even after 800 cycles at a high rate of 1 A g
−1, the capacity remains virtually unchanged at 1366.3 mAhg
−1.