Confining ultrafine SnS nanoparticles in hollow multichannel carbon nanofibers for boosting potassium storage properties

SnS has been extensively investigated as a potential anode material in potassium-ion batteries (PIBs) for its high theoretical capacity. Nonetheless, it suffers a limited cyclic lifespan owing to its poor electronic conductivity and huge volume expansion. This work proposed a facile approach where SnS nanocrystals are confined in the walls of hollow multichannel carbon nanofibers (denoted SnS@HMCFs) to tackle the issues above. In contrast to previous studies, impregnated ultrafine SnS nanocrystals in HMCFs compactly can increase the SnS loading number per unit area of the carbon matrix. Furthermore, the unique hollow multichannel carbon nanofibers are used as a robust carrier to uniformly distribute the SnS nanocrystals. This can significantly accelerate K⁺/electron transport, resulting in large specific capacity, outstanding rate performance, and steady cycling property for PIBs. High reversible capacities of 415.5 mAh g⁻¹ at 0.1 A g⁻¹ after 300 cycles and 245.5 mAh g⁻¹ at 1 A g⁻¹ after 1000 cycles are retained, suggesting great potential of SnS@HMCFs as a negative electrode material for PIBs. Additionally, when the SnS@HMCF anode is assembled with the KVPO₄F cathode, the obtained full cell shows a large discharge capacity of 165.3 mAh g⁻¹ after 200 cycles at 0.1 A g⁻¹.