Search

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). [ABSTRACT FROM AUTHOR]

Aqueous zinc‐ion battery (AZIBs) is expected to be an ideal device for large‐scale energy storage for its high safety and low cost. However, it is still a challenge to achieve both high energy density and high stability. Herein, in situ liquid‐phase growth exfoliation is developed to obtain V5O12 nanosheets, which is then combined with Ti3C2 nanosheets to construct two‐dimensional heterostructure (2D HVO@Ti3C2) with interfacial VOTi bonds. 2D HVO@Ti3C2 exhibits a dynamic interface coupling during discharging/charging, accompanied by break/reconstruction of interfacial VOTi bonds. The dynamic interface coupling provides a reversible electron transfer channel and endows the inert Ti3C2 with electrochemical activity in AZIBs, making it an additional electron acceptor and donor, and promoting the insertion of more Zn2+. Therefore, a capacity beyond the theoretical capacity of HVO is obtained for the HVO@Ti3C2. Additionally, the reversible 2D dynamic interface coupling can also effectively alleviate the structural damage during the cycling process. Then, the ultra‐high capacity (457.1 mAh g‐1 at 0.2 A g‐1, over 600 mAh g‐1 based on the mass of HVO) and high stability (88.9% capacity retention after 1000 cycles at 5 A g‐1) are achieved. This interface coupling mechanism provides an exciting strategy for the high energy density and high stability of AZIBs. [ABSTRACT FROM AUTHOR]