Zinc acetate activation-enhanced performance of hollow nano silica/carbon composite nanofibers for lithium-sulfur batteries

Here we develop a facile and scalable method to prepare silica/activated carbon nanofibers (SiO₂/ACNFs) via electrospinning a mixture of PAN and hollow SiO₂ nanospheres with following heat treatment, during which Zn(CH₃COO)₂ activation and PAN carbonization are simultaneously completed. When applied in lithium sulfur battery, the coin cells using S/SiO₂/ACNF composites as cathode material exhibit a high discharge specific capacity and long cycling life. The specific capacity at 0.5 and 1 C rates after 300 cycles still remains at 584 and 513 mA h g⁻¹, respectively, and the corresponding capacity decay is just 0.09% at 0.5 C and 0.13% at 1 C per cycle. The Zn(CH₃COO)₂ activation benefits sulfur loading and volume expansion suppression by creating numerous hierarchical pores in carbon nanofibers. Additionally, hollow SiO₂ nanospheres contribute to restrain the “shuttle effects” by adsorbing and releasing polysulfides reversibly. This kind of SiO₂/ACNF material and its fabrication method hold high potential for Li-S battery.