Deposition Mode Design of Li₂S: Transmitted Orbital Overlap Strategy in Highly Stable Lithium‐Sulfur Battery

Abstract Serious lithium polysulfides (LiPSs) shuttle effect and slow kinetic process lead to poor cycle performance and low working efficiency of lithium‐sulfur battery (Li‐S battery), which limits its commercialization. In this paper, a composite frame with transmitted orbital overlap is proposed as the functionalized separator of Li‐S battery (MX@WSSe/PP). It consists of WSSe nanosheets and MXenes nanosheets (MX). The experiments and theoretical calculations both show that MX@WSSe/PP can not only inhibit the LiPSs shuttle effect to realize the effective utilization of cathode materials, but also enhance the overall reversibility and reaction kinetics of the device by transforming the 2D deposition mode of Li₂S into 3D mode. The transformation of Li₂S deposition mode comes from the changed local charge density on MX@WSSe composite surface, which regulates the filling state of electron orbits and affects the orbital overlap between different atoms. This effect can even be transmitted to Li₂S molecules far from the surface of MX@WSSe. The capacity decay per cycle of Li‐S battery with MX@WSSe/PP is only 0.016% in 1000 cycles at 2 C. Also, a high area capacity of 9.39 mAh cm⁻² is achieved at high sulfur loading (10.2 mg cm⁻²) and low electrolyte/sulfur ratio (7.5 µL mg⁻¹).