The rapid development of battery community for portable electronics and electric vehicles has provoked an urgent demand for high-performance energy storage systems [1,2]. Lithium‑sulfur (LiS) batteries are a viable next-generation high energy density storage system for maintaining portable electronics and power batteries among new energy storage technologies because of its ultrahigh theoretical energy density (2600 Wh kg⁻¹), low cost, and non-toxicity [3]. However, the practical applications and commercialization of LiS batteries are restricted by multiple intrinsic limitations, including the insulating nature of active materials, volume expansion of cathode during discharge-charge process, dissolution and shuttle phenomenon of lithium polysulfides, sluggish reaction kinetics and high reaction energy barrier during cycles [[4], [5], [6]]. Thereinto, the shuttle effect and sluggish reaction kinetics of lithium polysulfide is directly related to the lithium/sulfur electrochemical reaction, which causes inferior reversible capacity and rapid capacity fade [[7], [8], [9]].

Numerous strategies have been devoted to conquer the above-mentioned challenges. Employing carbonaceous components as the cathode host or interlayer is one of the initial representative approaches for improve the performances of LiS batteries due to their good electrical conductivity and advantageous structural stability [[10], [11], [12]]. Additionally, the carbonaceous materials with fibrous architecture possess a rapid electronic transfer along the fibers and a large specific surface area to accomplish high sulfur loading in the LiS batteries [[13], [14], [15]]. Despite these initial demonstrations, the weak interaction between the nonpolar carbonaceous components with the polar polysulfide restrict the anchoring ability and reuse for polysulfide, suggesting that the shuttle effect of lithium polysulfide has not substantially been resolved. The shuttle effect of lithium polysulfide is essentially driven by the concentration gradient of soluble polysulfide. Therefore, a reliable solution that accelerates the conversion of polysulfide in the sulfur reduction reaction and sulfur evolution process is required to reduce the probability of lithium polysulfide shuttling and accelerate conversion reaction during cycling [[16], [17], [18]].

Recently, aiming to circumvent the issue, different polar hosts as catalysts have been introduced into the side of sulfur cathode to facilitate the adsorption and conversion of lithium polysulfides and finally suppress the shuttle effect, including transition metal oxides, sulfide, and nitride [[19], [20], [21], [22]]. The polarity materials possess not only strong polysulfides adsorbability by virtue of the Lewis acid–base coordination interaction, but also electrocatalytic effects due to the strong binding interactions with lithium polysulfides [23]. The electrocatalytic effects can accelerate lithium polysulfides conversion reaction (from soluble polysulfides species to insoluble Li₂S), which has been recognized in the aspect of mitigating the shuttling effect and improving reaction kinetics effectively [[24], [25], [26]].

Among these electrocatalysts, vanadium sulfide (VS₄) exhibits remarkable stability towards sulfur chemistries, low lithiation potential, and favorable charge diffusion and transfer structure [27,28]. VS₄ presents a conductive linear-chain structure that have associated a weak van der Waals forces between the parallel quasi-one-dimensional chains. Benefitting from this structural advantage, the lithium polysulfides can be effectively anchored on the V⁴⁺ (S₂²⁻)₂ chains and charge-transfer kinetics can be expedited in LiS batteries [29,30]. Taking into the above consideration, we expect that when incorporating the VS₄ nanocycles onto the carbon fibers, a reliable host will be constructed for inhibiting the shuttle effect and accelerating the conversion reaction of lithium polysulfides.

In this contribution, we devise a composite host with conductivity, adsorbability, and catalysis, which is constructed as a polysulfide trapper and catalyzer towards boost the intermediates immobilization and conversion in the side of sulfur cathode. In the composite host, VS₄ with a conductive linear-chain structure grow on carbon nanofiber (CF) derived from cattail. Benefiting from the synergism of the continuous CF matrix and polar VS₄ catalytic sites can significantly anchor polysulfides and expedite reaction kinetics in discharge and charge processes. Consequently, the LiS battery with CF/VS₄ host exhibits improved electrochemical energy storage feature, including prolong cycle performance excellent capacity recovery.