Three-Dimensional Ordered Porous Nanostructures for Lithium–Selenium Battery Cathodes That Confer Superior Energy-Storage Performance
Shengxuan Lin, Yuhang Chen, Yifan Wang, Zihe Cai, Jiajia Xiao, Tahir Muhmood, Xiaobin Hu
Abstract
Lithium–selenium (Li–Se) batteries suffer from the problems of polyselenides dissolution and volume expansion of active materials during the charge/discharge process. Moreover, the heavy atomic mass of selenium atoms limits the capacitive property of a Li–Se battery. Porous materials as the host for selenium particles reported by previous research studies are often disordered in pore structure and nonuniform in pore size. Herein, we report that a three-dimensional (3D) nitrogen-doped carbon photonic crystal (NCPC) with an ordered, interconnected structure was synthesized via a simple method to be the host of active materials. In addition, we prepared a Se-rich Se1–xSx by introducing a small amount of sulfur into a selenium ring to reduce the molecular mass but still keep the high electronic conductivity. As cathodes for a Li–Se battery, amorphous Se-rich Se1–xSx@NCPC composites exhibited high electrochemical performance with a specific capacity of 692 mA h g–1 at 0.1 Ag1–, an excellent rate capability of 526 mA h g–1 at 3 Ag1–, and an outstanding cycling property with an ultralow decay rate of 0.0132% per cycle at 0.6 Ag1– over 1000 cycles. Moreover, the pouch cell of Se1–xSx@NCPC composites also showed a good property with an energy of 253 Wh kg–1 at 0.1 Ag1– and an outstanding rate energy of 192 Wh kg–1 at 1.5 Ag1–, manifesting great potential in practical application.