Porous Heteroatom-Doped Ti<sub>3</sub>C<sub>2</sub>T<sub><i>x</i></sub> MXene Microspheres Enable Strong Adsorption of Sodium Polysulfides for Long-Life Room-Temperature Sodium–Sulfur Batteries
Weizhai Bao, Ronghao Wang, Chengfei Qian, Zherui Zhang, Ruijun Wu, Yuhao Zhang, Fangyang Liu, Jingfa Li, Guoxiu Wang
Abstract
The practical application of Na–S batteries is largely hindered by their low mass loading, inferior rate capability, and poor cycling performance. Herein, we report a design strategy for encapsulation of sodium polysulfides using Ti3C2Tx MXene. Porous nitrogen-doped Ti3C2Tx MXene microspheres have been synthesized by a facile synthesis method. Porous nitrogen-doped Ti3C2Tx MXene microspheres contain abundant pore structures and heteroatom functional groups for structural and chemical synergistic encapsulation of sodium polysulfides. Sodium–sulfur batteries, based on the as-proposed cathode, demonstrated outstanding electrochemical performances, including a high reversible capacity (980 mAh g–1 at 0.5 C rate) and extended cycling stability (450.1 mAh g–1 at 2 C after 1000 cycles at a high areal sulfur loading of 5.5 mg cm–2). This MXene-based hybrid material is a promising cathode host material for polysulfide-retention, enabling high-performance Na–S batteries.