Built-in skeleton Cu/NC-NFs as a sulfur carrier for lithium sulfur batteries

Abstract

Carbon nanofibers are commendable sulfur carriers for Li–S batteries; however, conventional nanofibers often suffer from significant adhesion to each other during the carbonization process, which limits the catalytic activity and the conversion redox of lithium polysulfides. In this study, a Cu/NC-NF material with a uniform nanofiber structure was designed and synthesized as a cathode for Li–S batteries. The built-in skeleton derived from HKUST-1 can prevent the adhesion of the nanofibers, while generating homogeneously distributed catalytic sites for fast lithium polysulfide redox kinetics and the structure stabilizes over extended cycling. The Cu/NC-NFs, serving as a sulfur carrier, exhibit exceptional electrochemical performance for Li–S batteries, achieving a high discharge specific capacity of 884.9 mA h g⁻¹ at 0.5C, while also demonstrating a low capacity fading of only 0.06% per cycle.