Preparation and properties of carbon-modified Ni-CNT@C applied to high-performance lithium-sulfur battery

In this study, we developed a novel carrier material (Ni-CNT@C) by using a hard template method and in situ growth of carbon nanotubes within a porous carbon framework. We conducted a comprehensive analysis of the electrochemical properties of this material. Our results show that Ni-CNT@C features a highly porous, hierarchical structure that significantly enhances the catalytic activity. This structure reduces the shuttle effect of lithium polysulfides and improves their utilization rate. Electrochemical tests reveal that the Ni-CNT@C/S-based battery achieves an impressive initial discharge capacity of 1212 mAh/g at a current density of 0.5 A/g. After 100 cycles, the battery retains a capacity of 849 mAh/g. At a higher current density of 1 A/g, the capacity remains at 585 mAh/g after 300 cycles. Remarkably, at a current density of 5 A/g, the battery maintains a substantial capacity of 362 mAh/g. Furthermore, reducing the current density to 0.1 A/g causes the capacity to rebound to 933 mAh/g, showcasing the exceptional rate performance of the Ni-CNT@C/S cathode material. Additionally, extensive adsorption tests and impedance analyses confirm the superior polysulfide adsorption capability of Ni-CNT@C. This approach integrates the catalytic properties of nickel, the unique structural features of carbon materials, and nitrogen doping, providing a promising solution to the challenges faced by lithium-sulfur batteries.