Preparation and Application of Nanorod FeOOH/CNT@S Composites for High-Performance Lithium-Sulfur Batteries

The shuttle effect from the dissolution of intermediate lithium polysulfides in the electrolyte and the poor conductivity of sublimated sulfur hinder the commercialization of lithium-sulfur (Li-S) batteries. A one-step hydrothermal method is used to synthesize a nanorod iron hydroxide/carbon nanotube (FeOOH/CNT) composite. The UV-vis experiment shows that the FeOOH/CNT composite is beneficial to adsorption of the Li2S6 solution, which can be attributed to the strong interaction between the Li2S6 solution and the FeOOH/CNT composite. Meanwhile, the introduction of CNTs facilitates rapid electron transfer, leading to a decreased charge-Transfer resistance value of the whole electrode. The FeOOH/CNT@S-M composite was prepared by mixing sulfur particles and the FeOOH/CNT composite with ball milling. Further, the synthesized FeOOH/CNT@S-A provides a strong interaction between the FeOOH/CNT composite and sulfur particles after annealing. The S-O and C-S bonds observed in XPS results further confirmed the strong adsorption ability between the two substances, resulting in a suppressed shuttle effect. Eventually, the FeOOH/CNT@S-A electrode has an initial discharge specific capacity of 1290 mA h g-1 at a current density of 0.1 A g-1. After cycling for 200 cycles, the electrode displays a discharge specific capacity of 742 mA h g-1 (at 1 A g-1) with â 88.5% capacity retention, revealing its good cycling stability. This work demonstrates the potential application of FeOOH/CNT@S-A composite materials in high-performance Li-S batteries.