SnP0.94 nanodots confined carbon aerogel with porous hollow superstructures as an exceptional polysulfide electrocatalyst and “adsorption nest” to enable enhanced lithium-sulfur batteries
By Gao, Xiaogang; Huang, Ying; Li, Xiang; Gao, Heng; Li, Tiehu
Published in Chemical Engineering Journal
2021
Abstract
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 SnP0.94 nanodot electrocatalysts@porous hollow carbon aerogel (SnP0.94@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, SnP0.94 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 SnP0.94@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 mgs−1). This work opens up a new direction for constructing the electroactive hosts in Li-S batteries.