Investigation of electrochemical performance of Co-NC@CNT@MoS2/S composite materials as cathodes for lithium-sulfur batteries

To address the challenges of volume expansion and the shuttle effect in lithium-sulfur batteries, a composite material comprising porous carbon, carbon nanotubes, and molybdenum disulfide has been developed. The porous carbon material Co-NC is derived from the pyrolysis of the metal–organic framework ZIF-67. It exhibits a high specific surface area and an extensive pore structure, which enhance battery performance. Carbon nanotubes (CNTs) provide excellent electrical conductivity to the composites. Additionally, the inclusion of MoS2 enables the absorption of dissolved polysulfides and catalyzes their conversion into insoluble forms, effectively suppressing the shuttle effect and mitigating capacity degradation. This composite effectively combines the beneficial properties of porous carbon Co-NC and the multi-component CNT@MoS2, significantly improving the electrochemical performance of the battery. At a current density of 0.1 C, the Co-NC@CNT@MoS2 composite achieves an impressive initial discharge specific capacity of up to 1325.3 mAh/g. After 500 cycles at 1 C, the composite demonstrates a capacity retention rate of 70 %, while maintaining a coulombic efficiency above 98 %.