Rapid Growth of Bi<sub>2</sub>Se<sub>3</sub> Nanodots on MXene Nanosheets at Room Temperature for Promoting Sulfur Redox Kinetics
Chuanliang Wei, Baojuan Xi, Peng Wang, Zhengran Wang, Xuguang An, Yuan Li, Jinkui Feng, Shenglin Xiong
Abstract
Li–S batteries are hampered by problems with their cathodes and anodes simultaneously. The improvement of Li–S batteries needs to consider both the anode and cathode. Herein, a Bi 2 Se 3 @MXene composite is prepared for the first time by rapidly growing Bi 2 Se 3 nanodots on two-dimensional (2D) MXene nanosheets at room temperature through simply adding high-reactive hydroxyethylthioselenide in Bi 3+ /MXene aqueous solution. Bi 2 Se 3 @MXene exhibits a 2D structure due to the template effect of 2D MXene. Bi 2 Se 3 @MXene can not only facilitate the conversion of lithium polysulfides (LiPSs) but also inhibit their shuttling in the S cathode due to its catalytic effect and adsorption force with LiPSs. Bi 2 Se 3 @MXene can also be used as an interfacial lithiophilic layer to inhibit Li dendrite growth in the Li metal anode. Theoretical calculations reveal that Bi 2 Se 3 nanodots in Bi 2 Se 3 @MXene can effectively boost the adsorption ability with LiPSs, and the MXene in Bi 2 Se 3 @MXene can accelerate the electron transport. Under the bidirectional regulation of Bi 2 Se 3 @MXene in the Li metal anode and S cathode, the Li–S battery shows an enhanced electrochemical performance.