Mesoporous carbon prepared by etching halloysite nanotubes (HNTs) with pyrrole as a precursor for a sulfur carrier of superior lithium–sulfur batteries

Abstract

Using pyrrole as a carbon precursor and halloysite nanotubes (HNT) as a templating agent, mesoporous carbon (MC) was prepared by template etching and combined with sulfur as a composite cathode for lithium–sulfur batteries. The mesoporous carbon/sulfur (MC/S) composite cathode exhibits a first cycle discharge specific capacity of 1355 mA h g⁻¹ at 0.2C, and the utilization rate of active sulfur can reach 80.9%. Even after 500 cycles, the discharge specific capacity still remains at 496.9 mA h g⁻¹ when tested at 0.5C. Furthermore, the hollow groove structure present in the MC/S electrode provides a large number of active sites for electrochemical reactions. The prepared MC/S composite cathode not only has a high discharge specific capacity and good cycle stability, but also increases the energy density of the lithium–sulfur battery. Therefore, this preparation process of MC is more conducive to practical application.