MoS2/SnS@B, P-doped hollow multi-channel carbon fibers for lithium-ion batteries

Abstract

Stannous sulfide (SnS) with a unique two-dimensional layered structure is a potential anode material for advanced lithium-ion batteries due to its large interlayer spacing (4.04 Å) and high theoretical specific capacity (1138 mA h g⁻¹). However, large volume expansion and low conductivity lead to poor cycle performance of SnS. In this work, MoS₂ modified SnS@ hollow multichannel carbon fibers (MoS₂/SnS@HMCFs) were prepared by an electrospinning technique and a hydrothermal method. The resulting material has a unique hollow structure with a heterojunction formed between SnS and MoS₂. It not only mitigates the volume change of SnS in the lithiation/delithiation process but also improves the interfacial transport of Li⁺ and enhances the structural stability of the electrode materials. MoS₂/SnS@HMCFs can maintain a reversible specific capacity of 610.1 mA h g⁻¹ (at 0.5 A g⁻¹) after 500 cycles. On this basis, B and P elements were doped into MoS₂/SnS@HMCFs to generate lattice defects and accelerate electron transport and further ameliorate the electrical conductivity (from 5.34 S cm⁻¹ to 9.58 S cm⁻¹). In light of the above advantages, the reversible specific capacity of MoS₂/SnS@BP-HMCFs is increased to 854.4 mA h g⁻¹ (0.5 A g⁻¹) after 500 cycles compared with MoS₂/SnS@HMCFs. Therefore, an anode with a unique hollow structure, heterogeneous structural framework, and doped heteroatoms was constructed, providing a method for the preparation of anode materials tailored for high-performance lithium-ion batteries.