Reasonable suppression of polysulfides/polyselenides shuttle based on MXene in Na‐SeS <sub>2</sub> batteries
Qiuju Yang, Jing Zhao, Wei Gao, Wei Zhong, Yuruo Qi, Jin Han, Shu‐Juan Bao, Maowen Xu
Abstract
Abstract Metal‐sulfur/selenium batteries have become the focus of new‐generation energy storage systems due to the advantages of low‐cost and high energy density. However, it still suffers from the notorious shuttle of polysulfides/polyselenides, poor electronic conductivity and tremendous volume expansion. Herein, a dual defense system for polysulfides/polyselenides was proposed and constructed based on MXene. The nitrogen‐doped porous carbon (NPC) decorated by Ti 3 C 2 T x MXene (M@NPC) was employed as the SeS 2 host (SeS 2 @M@NPC). Particularly, Ti 3 C 2 T x sheets wrapped on NPC guarantee the rapid ion diffusion and serve as the first barrier for SeS 2 and dissolved sodium polysulfides/polyselenides. Meanwhile, the few‐layered Ti 3 C 2 T x sheets coated on glass fiber separators act as the second barrier for alleviating the shuttle of polysulfides/polyselenides through physical interception and chemical adsorption. With this elaborate design, the integrated Na‐SeS 2 battery achieves a high specific capacity of 1243 mAh·g −1 at 1.0C, revealing a distinct superiority over its counterparts (SeS 2 @M@NPC, 1083 mAh·g −1 at 0.5C; and SeS 2 @NPC, 823 mAh·g −1 at 0.5C). The findings gained in this work provide a creative idea for the construction of durable room‐temperature Na‐SeS 2 batteries based on MXenes and their derivative materials.