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Li-S batteries suffered from the severe "shuttle effect", resulting in poor conversion kinetics and limited life-span. This work proposed an electrochemical active porous architecture (EPA) interlayer to regulate the migration of ions and electrons, and highlights the importance of porous structure design and chemical modification of functional interlayer for reliable lithium–sulfur batteries. [Display omitted] • An electrochemical active porous architecture (EPA) is synthesized through hydrothermal reaction and heat treatment (550 °C) under ammonia atmosphere. • The EPA displays a sponge-like porous morphology with an interconnected porous structure and decorated numerous VN nanoparticles, and achieves strong chemical interaction toward lithium polysulfides and enhanced electrolyte diffusion. • The liquid–solid transformation kinetics of polysulfides can be accelerated in the EPA + TMM separator, thereby further achieving a dense and smooth Li deposition morphology. • Low polarization, high initial discharge capacity, good rate capabilities, and excellent cycling performance are achieved. Although lithium–sulfur batteries have excellent theoretical specific capacity (1675 mAh g−1) and high energy density (2600 wh kg−1), their practical application is hampered by the severe "shuttle effect" of polysulfides in ether-based electrolytes. Soluble polysulfides can migrate across separator and react with lithium metal, resulting in a rapid capacity decay. In this study, we proposed an electrochemical active porous architecture (EPA) interlayer to address this tricky issue. Firstly, the porous architecture guarantees efficient electrolyte diffusion. Additionally, the catalytic vanadium nitride particles within the conductive skeleton can capture soluble polysulfides, accelerate their redox reaction, and suppress the "shuttle effect", thereby further restraining the parasitic reaction between lithium metal anode and polysulfides. Therefore, integrating the EPA interlayer in the battery enables an initial capability of 1465.8 mAh g−1 at 0.1C and delivers a good rate performance at 2.0C (668.0 mAh g−1). The battery achieves an average capacity of 796.7 mAh g−1 within the first 500 cycles under 0.5C, with a high average Coulombic efficiency of 99.8 %, indicating the practical potential of EPA interlayer design for application in reliable lithium–sulfur batteries. [ABSTRACT FROM AUTHOR]

Lithium–sulfur batteries are considered as the next generation of energy storage systems because of their high theoretical specific capacity and energy density. Unfortunately, the sluggish reaction kinetics, weak adsorption toward to lithium polysulfides, and slow lithium ion diffusion impede the smooth electrochemical process, resulting in the lithium–sulfur batteries with the unsatisfactory cycling stability and rate performance. Since it is recognized that polar metal oxides and doped nitrogen in carbon materials have chemical interaction with lithium polysulfides, a nanostructured nitrogen-doped porous carbon/MoO2 composite is synthesized through a simple hydrothermal method by using graphene oxide nanoribbon and phosphomolybdic acid hydrate as precursors. The porous nanostructure promotes the charge and mass transport, while MoO2 nanoparticles immobilize lithium polysulfides via strong chemisorption and enhance the redox kinetics of polysulfides owing to the efficient catalytic activity in liquid–solid boundary. Consequently, the as-obtained nanostructured porous carbon/MoO2-based sulfur cathode exhibits low polarization, high initial discharge capacity (1403 mAh g−1 at 0.1 C), good rate capabilities (584 mAh g−1 at 4 C), and impressive cycling performance at 1 C (503 mAh g−1 after 500 cycles with capacity fade rate of 0.07% per cycle). [ABSTRACT FROM AUTHOR]

Two reported three-dimensional covalent organic frameworks (3D-COFs), COF-300 and COF-301, which have hierarchical porous structures and large pore volumes, were synthesized and employed as host materials for lithium-sulfur batteries. Owing to possessing excellent porosities as well as abundant hydroxyl groups in the pore walls, COF-301 can not only trap lithium polysulfides (PSs) via physical adsorption inside the pores, but also capture PSs by chemical interactions to relieve the shuttle effect. Interestingly, it is the first time that 3D-COFs were utilized as host materials for lithium-sulfur batteries as well as hydroxyl groups were introduced into COFs for improving the battery performance. As a result, COF-301@S as cathode material could reserve the capacity of 411.6 mA·h·g−1 after 500 cycles with only 0.081% fading per cycle at 0.5 C, exhibiting better battery performance compared with COF-300@S. This study not only expands the applications of 3D-COFs but also provides a new route for designing lithium-sulfur batteries. [ABSTRACT FROM AUTHOR]