SnP_0.94 nanodots confined carbon aerogel with porous hollow superstructures as an exceptional polysulfide electrocatalyst and “adsorption nest” to enable enhanced lithium-sulfur batteries

The realization of the high energy density of lithium-sulfur batteries (Li-S) has always been one of the targets pursued by researchers. However, the shuttling effect, dissolution of sulfur/lithium polysulfides (LiPSs), and sluggish redox kinetics in Li-S batteries restricted its long-term application and development. Herein, an advanced sulfur immobilizer composed of SnP_0.94 nanodot electrocatalysts@porous hollow carbon aerogel (SnP_0.94@PHCA) was synthesized. As expected, the synergistic sulfur host can not only act as a good electrochemical interface but also provide adequate accommodation for active materials to alleviate the LiPS diffusion. More importantly, SnP_0.94 nanodot electrocatalysts supported on the conductive PHCA skeleton effectively expedited the conversion/redox reaction kinetics and also constructed a stronger adsorption system for LiPSs to inhibit the LiPS shuttling behavior. Correspondingly, the SnP_0.94@PHCA composite endowed the sulfur cathode the outstanding specific capacity of 1017.8 mAh g⁻¹ under a high sulfur loading (2.94 mg cm⁻²) at 0. 1 C, superior rate performance (579.8 mAh g⁻¹ at 1 C), excellent cycling stability (the capacity decay rate of 0.13% per cycle at 0.5 C), and a high areal capacity of 6.9 mAh cm⁻² under starved electrolyte conditions (8.6 μL mg_s⁻¹). This work opens up a new direction for constructing the electroactive hosts in Li-S batteries.