A melt-diffusion strategy for tunable sulfur loading on CC@MoS2 for lithium–sulfur batteries
Chengxiang Tian, Juwei Wu, Zheng Ma, Bo Li, Xu Zhang, Xiaotao Zu, Xia Xiang, Sean Li
Abstract
For lithium–sulfur batteries, 3D cathodes might be of interest for containing the active material and trapping the polysulfides during cycling, owing to their binder-free and freestanding features. In this work, the MoS2 grown on the 3D structured Carbon Cloth ([email protected]2) is firstly used to fabricate the Li–S battery and the sulfur loading can be freely tuned by adjusting thermal annealing time at 200 °C. A two-step melt-diffusion strategy is reported for fabrication of cathodes, which involves in melting and diffusion of sulfur covered by [email protected]2 composites instead of dissolution of sulfur in the toxic organic solvents. Compared with the non-polar carbon cloth, the [email protected]2 composites exhibit better adsorption capacity for polysulfides due to more edge active sites, which could effectively facilitate polysulfide redox kinetics. The SEM images of the [email protected]2 cathode after 300 cycles show that MoS2 can still maintain the nanosheet morphology. After 300 cycles at 0.5 C, the [email protected]2 cathodes loaded with 2 mg sulfur exhibit a better reversible capacity of 698 mA h g−1 compared with [email protected]2 loaded with 1 mg sulfur (604 mA h g−1) and [email protected]2 loaded with 4 mg sulfur (420 mA h g−1). This work proposes an environmentally friendly method to fabricate the lithium–sulfur battery cathode material and the sulfur loading can be freely adjusted.