Science Daily December 7, 2022
The issues arising from the low S mass loading and poor cycling stability caused by the shuttle effect of polysulfides seriously limit the operating capacity and cycling capability of room-temperature sodium–sulfur (RT-Na/S) batteries. An international team of researchers (China, Australia) synthesized sulfur-doped graphene frameworks supporting atomically dispersed 2H-MoS2 and Mo1 (S@MoS2-Mo1/SGF) with a record high sulfur mass loading of 80.9 wt.% as an integrated dual active sites cathode for RT-Na/S batteries. They displayed unprecedented cyclic stability with a high initial capacity and a low-capacity fading rate of 0.05% per cycle over 1000 cycles. Experimental and computational results revealed that atomic-level Mo in the integrated dual-active-site forms a delocalized electron system, which could improve the reactivity of sulfur and reaction reversibility of S and Na, greatly alleviating the shuttle effect. According to the researchers the findings provide an effective strategy to fabricate high-performance dual-site cathodes, and better understanding of their enhancement mechanisms at an atomic level…read more. Open Access TECHNICAL ARTICLEÂ
Electron microscopy images. a–c) TEM, HAADF-STEM image… Credit: Advanced Materials, 29 October 2022Â