Effect of S-doped carbon nanotubes as a positive conductive agent in lithium-ion batteries

In this paper, sulfur-doped carbon nanotubes were synthesized and modified at 600, 700, and 800 °C. The results showed that the amount of sulfur doped in carbon nanotubes increased with the increase of temperature, which were 0.78%, 0.98%, and 1.07%, respectively, but the carbon/sulfur binding mode did not change. At the same time, sulfur doping significantly increased the specific surface area, which was conducive to improving the infiltration of the electrolyte into the electrode piece. Sulfur-doped carbon nanotubes are used as conductive agents for the cathode NCM523 of lithium-ion batteries, and compared with untreated carbon nanotubes, they effectively improve the battery polarization, reduce the internal resistance, and greatly improve the ratio performance, and in terms of cycling performance, the capacity retention rate of the battery is increased from 71.3% to 81~85%.