Duan, Ruixian, Li, Xifei, Cao, Guiqiang, Jiang, Qinting, Li, Jun, Chen, Liping, Wang, Jingjing, Hou, Chenyang, Li, Ming, Yang, Zihao, Yang, Xuan, Zuo, Jiaxuan, Xi, Yukun, Xie, Chong, Wang, Jing, Li, Wenbin, and Zhang, Jiujun
Novel charge distribution regulation strategy for Mo 2 C, the relationships of Interface-Structure-Property in heterostructures were clarified, facilitating efficient adsorption-catalysis of Li 2 S x (1≤x≤4) [Display omitted] • A novel electronic distribution regulation strategy (Mo-Mo 2 C heterostructure) for molybdenum carbide was developed. • The relationship of the heterointerfaces-structure–property in Mo-Mo 2 C has been clarified. • The modulation of the intrinsic electronic distribution of Mo 2 C results higher adsorption energy for lithium polysulfides (LiPSs) and stronger Mo-S bonding strength. • The sulfur cathode with C@Mo-Mo 2 C an excellent high-rate cyclic performance accompanied by capacity decay rate of 0.08 % per cycle after 400 cycles at 2 C. Heterostructure engineering is considered a crucial strategy to modulate the intrinsic charge transfer behavior of materials, enhance catalytic activity, and optimize sulfur electrochemical processes. However, parsing the role of heterogeneous interface-structure–property relationships in heterostructures is still a key scientific issue to realize the efficient catalytic conversion of polysulfides. Based on this, molybdenum carbide (Mo 2 C) was successfully partial reduced to molybdenum metal (Mo) via a thermal reduction at high-temperature and the typical Mo-Mo 2 C-based Mott-Schottky heterostructures were simultaneously constructed, which realized the modulation of the electronic structure of Mo 2 C and optimized the conversion process of lithium polysulfides (LPS). Compared with single molybdenum carbide, the modulated molybdenum carbide acts as an electron donor with stronger Mo-S bonding strength as well as higher polysulfide adsorption energy, faster Li 2 S conversion kinetics, and greatly facilitates the adsorption → catalysis process of LPS. As a result, yolk-shell Mo-Mo 2 C heterostructure (C@Mo-Mo 2 C) exhibits excellent cycling performance as a sulfur host, with a discharge specific capacity of 488.41 mAh g−1 for C@Mo-Mo 2 C/S at 4 C and present an excellent high-rate cyclic performance accompanied by capacity decay rate of 0.08 % per cycle after 400 cycles at 2 C. Heterostructure-acting Mo 2 C electron distribution modulation engineering may contributes to the understanding of the structure-interface-property interaction law in heterostructures and further enables the efficient modulation of the chemical behavior of sulfur. [ABSTRACT FROM AUTHOR]