Effect of NiCoO2-x-CNTs/S cathode on electrochemical performance of Lithium-sulfur batteries

Lithium-sulfur batteries are a potential choice for future energy storage due to their low cost, abundant resources, non-toxicity, and environmental friendliness. However, problems such as insufficient battery conductivity, volume expansion, and shuttle effect constrain their further development. In this study, carbon nanotubes (CNTs) were composited with NiCoO2-x, an oxygen vacancy bimetallic oxide with excellent electrochemical properties, as cathode materials for lithium-sulfur batteries. The experiment result shows that the NiCoO2-x/CNTs composite material outperformed pure CNTs. At a 0.1 C rate, the discharge specific capacity of the composite was 1289.9 mAh/g, with an active material utilization of 77%, compared to 881.9 mAh/g and 52.65% for pure CNTs. The composite material exhibited excellent rate performance, maintaining a high discharge specific capacity even at higher rates. Long-term cycling tests revealed a capacity retention of 74.68% after 200 cycles for the composite material, compared to significantly lower retention for CNTs. This study provides new ideas for the study of lithium-sulfur batteries.