Anion‐Doped Cobalt Selenide with Porous Architecture for High‐Rate and Flexible Lithium–Sulfur Batteries
Tao Feng, Teng Zhao, Shuangfei Zhu, Nanxiang Zhang, Zhuangzhuang Wei, Ke Wang, Li Li, Feng Wu, Renjie Chen
Abstract
Abstract Emerging catalytic host for sulfur is an effective approach to breaking the limits of lithium–sulfur batteries for practical applications. Herein, the hydrangea‐shaped Co 0.85 Se electrocatalyst with macroporous architecture is synthesized. Besides, to improve the electronic conductivity of Co 0.85 Se, some defects (S‐doped) are introduced into the structure of crystals. The S‐doped Co 0.85 Se exhibited an outstanding electrocatalytic effect on lithium polysulfides conversion and can induce and regulate uniform growth of insoluble Li 2 S on its surface due to the synergistic adsorption by Se and S. As a result, the S/C cathode achieved a high initial capacity of 1340.6 mAh g −1 at 0.5 C and a stable cycling capacity of 666.6 mAh g −1 at 1 C after 500 cycles by 5 wt% Co 0.85 SeS additions. Moreover, high S loading cathodes are designed through in situ synthesis of Co 0.85 SeS on flexible carbon cloth (Co 0.85 SeS@CC). The porous and open framework of Co 0.85 SeS@CC facilitated electrolyte infiltration and accommodated the volume change of sulfur during the charge/discharge process. Taking by these advantages, a high areal capacity of 9.663 mAh cm −2 is achieved at a high sulfur loading of 9.98 mg cm −2 . Even at a high current density of 15 mA cm −2 , a reversible capacity of 603.7 mAh g −1 is maintained at a sulfur loading of 6.52 mg cm −2 . This proposed work provides a feasible approach to high‐rate and flexible Li–S batteries.