Interface-driven D-band modulation for dual-function anchoring and catalytic conversion of polysulfides in lithium-sulfur batteries

Abstract

The polysulfide shuttle effect critically hinders lithium-sulfur (LiS) battery development, therefore, the design of heterogeneous interface engineering with “adsorption-catalysis” functions for polysulfide conversion has garnered considerable attention. However, the exploration of the intricate relationship between key electronic properties and catalytic activity at such interfaces remains a challenge. Additionally, a comprehensive understanding of the thermodynamic growth mechanisms for heterostructure materials is lacking. Herein, a Ni-based homologous structure was precisely constructed via thermodynamic control, with a specific focus on optimizing the interface design. The theoretical results show that the heterostructures with adjustable composition realize the appropriate upward shift to the D-band, improving the affinity towards polysulfide, and further reducing the reaction energy barrier. On this basis, the relationship between interface design and the D-band center, as well as catalytic performance, was established. Specifically, M-Ni₃Fe/Ni₃ZnC_0.7 accomplishes the electron enrichment at the interface, supporting the further diffusion of polysulfides, and lowering the LiS bond energy, performing the bidirectional catalytic transformation of polysulfides. As a result, the LiS batteries with the cathode of M-Ni₃Fe/Ni₃ZnC_0.7/S deliver rate performances of discharge capacity of 514 mA h g⁻¹ at 5.0 C. This understanding of the D-band and interfacial design provides a framework for LiS catalyst optimization.