Lewis Acidic/Basic Oxides Modulated Cu <sub>3</sub> P for Efficient Lithium Polysulfide Electrocatalytic Conversion
Fengxing Liang, Huanfeng Xiang, Manchuan Guo, Xijun Liu, Jinliang Zhu
Abstract
Abstract Addressing sluggish reaction kinetics and the shuttling of lithium polysulfides (LiPSs) requires the development of efficient electrocatalysts in lithium–sulfur (Li─S) batteries. Here, novel Cu 3 P heterostructure catalysts is synthesized, modulated by Lewis acidic/basic metal oxides (Cu 3 P‐MO, where M = Zn or Mg), in order to facilitate the conversion of LiPSs. Specifically, the Lewis acidic oxide ZnO in Cu 3 P‐ZnO captured electrons from Cu 3 P, resulting in an upward shift of the d‐band center of Cu ( E Cu‐3d ). This enhanced the adsorption of Lewis basic polysulfides, reduced the activation energy of the polysulfide reduction reaction, and significantly accelerated the reaction kinetics. As anticipated, the Cu 3 P‐ZnO catalyst on porous carbon (Cu 3 P‐ZnO/PC) effectively promoted the electrocatalytic conversion and suppressed the shuttling of LiPSs. The Cu 3 P‐ZnO/PC@S cathode demonstrated exceptional cycling stability, maintaining performance over 2000 cycles at 4 C with an ultralow decay rate of 0.014% per cycle, achieving a remarkable rate capability of 665 mAh g −1 at 8 C. Further, in situ X‐ray diffraction analysis is employed to elucidate the conversion mechanisms of sulfur species during the charge/discharge process. Notably, the Li─S pouch cell equipped with the Cu 3 P‐ZnO/PC@S cathode delivered a high energy density of 415.8 Wh kg −1 .