The shuttle effect and slow reaction kinetics of soluble lithium polysulfides (LiPSs) have a significant impact on the cycle life and rapid charging and discharging capacity of lithium-sulfur (Li-S) batteries. Herein, the Fe-based MBene material was adopted to alleviate the above problems. Unlike previous LiF etching techniques, petal-shaped Fe2Al1-xB2 was obtained through simple, nontoxic alkaline solution etching. The sheet-like two-dimensional structure not only effectively provided a large quantity of FeB adsorption active sites but also effectively reduced the resistance to charge transfer. Based on these advantages, the sulfur cathode modified with Fe2Al1-xB2 thin layers achieved reversible capacities of 1103 and 478 mA h g-1 at rates of 0.2 and 4 C, respectively. Even under high loading, the solution could provide an initial areal capacity of 5.4 mg cm-2. It provided a new idea for the Li-S application of Fe-based two-dimensional borides.
Yang et al. (Thu,) studied this question.