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Hydroxylated multi-walled carbon nanotubes were introduced into sulfur cathodes to utilize the hydrophilic attraction between the OH group and polysulfides as well as to increase the utilization of sulfur. This approach shows a promising strategy for diminishing the polysulfides shuttling behavior and improving the electrochemical performance of lithium–sulfur batteries. [ABSTRACT FROM AUTHOR]

• FMMO–NR is introduced as a catalytic host for lithium sulfur batteries. • Fast conversion reactions LiPSs and immobilization of LiPSs are enabled by FMMO–NR. • FMMO–NR presents outstanding rate capability and stable cyclability. • FMMO–NR shows outstanding cyclability with a high sulfur loading of 5 mg cm–2. Lithium sulfur (Li–S) batteries have been intensively studied as promising energy storage devices due to their high theoretical specific capacity and cost effectiveness. However, the poor cycle life and low Coulombic efficiency caused by the insulating nature of sulfur and shuttle effect of lithium polysulfides (LiPSs) still hinder the practical implementation of Li–S batteries. Here, we report Fe 2 (MoO 4) 3 decorated MoO 3 nanorod (FMMO–NR) heterostructure as an efficient catalytic host for Li–S batteries. Fe 2 (MoO 4) 3 has low electrical conductivity, but excellent catalytic activity, and MoO 3 has high electrical conductivity but low catalytic activity. With the synergistic advantages of the high electrical conductivity of one-dimensional MoO 3 nanorod and strong catalytic activity of Fe 2 (MoO 4) 3 with a redox potential of ∼2.9 V, FMMO–NR enables fast conversion reactions of long-chain LiPSs to Li 2 S 2 /Li 2 S and suppresses the shuttle effect by immobilization of LiPSs with strong binding. The FMMO–NR electrode shows a high discharge capacity of 1588 mAh g −1 and stable cycle performance with a capacity retention of 70% at 2 C over 500 cycles. Even with a high sulfur loading of 5 mg cm–2, the FMMO–NR electrode presents outstanding cycling stability with a capacity retention of 73% over 100 cycles. [ABSTRACT FROM AUTHOR]

Lithium–sulfur (Li-S) batteries hold promise as high-energy storage systems; however, their practical application is hindered by challenges such as the shuttle effect of lithium polysulfides (LiPSs) and sluggish redox kinetics. In this study, we designed and synthesized Ti 3 C 2 T x /NbSe 2 electrocatalyst through in-situ hydrothermal growth and selenization steps. NbCl 5 was selenized to form Ti 3 C 2 T x /NbSe 2 , which was evaluated as a cathode material. The resulting Ti 3 C 2 T x /NbSe 2 material was precisely characterized by FESEM, TEM, XRD and XPS analyses. The Ti 3 C 2 T x /NbSe 2 exhibited a high BET specific surface area of 89.16 m2 g−1 and a pore volume of 0.098 cm3 g−1, indicating enhanced adsorption capabilities for LiPSs. Electrochemical performance tests demonstrated the superior catalytic activity and redox kinetics of Ti 3 C 2 T x /NbSe 2 compared to those of pure Ti 3 C 2 T x and NbSe 2. Cyclic voltammetry (CV) profiles indicated higher current densities, and Tafel plots revealed an increased exchange current density of 1.19 mA cm−2 for the Ti 3 C 2 T x /NbSe 2. Li 2 S precipitation experiments showed an enhanced precipitation current density of 416.8 mA g−1 and a higher capacity of 198.6 mAh g−1 for the Ti 3 C 2 T x /NbSe 2. The S/Ti 3 C 2 T x /NbSe 2 cathode exhibited outstanding rate capabilities, with capacities of 1389–716 mAh g−1 at current densities of 0.1–5 C, respectively. Moreover, it maintained a high discharge capacity of 954 mAh g−1 when the current density returned to 0.5 C. The long-term cycling stability was demonstrated with a capacity retention of 94.8 % over 550 cycles at 0.5 C, significantly outperforming the S/Ti 3 C 2 T x and S/NbSe 2 cathodes. Additionally, under a high sulfur loading of 6.5 mg cm−2 at 0.2 C, the S/Ti 3 C 2 T x /NbSe 2 cathode exhibited an initial area capacity of 6.13 mAh cm−2, retaining a capacity of 3.45 mAh cm−2 after 300 cycles. [Display omitted] • Ti 3 C 2 T x /NbSe 2 synthesized via in-situ selenization, confirmed by FESEM, TEM, XRD, XPS. • Ti 3 C 2 T x /NbSe 2 exhibited a higher Li 2 S precipitation current density of 416.8 mA g˗1. • S/Ti 3 C 2 T x /NbSe 2 cathode exhibited a discharge capacities at 1389 mAh g˗1 at 0.1C. • S/Ti 3 C 2 T x /NbSe 2 remarkable capacity retention of 94.8% over 550 cycles at 0.5C. • S/Ti 3 C 2 T x /NbSe 2 presented a retaining 3.45 mAh cm-2 after 300 cycles. [ABSTRACT FROM AUTHOR]

• Yolk shell structured ZnO/C sphere was synthesized by a facile RF sol-gel method. • Li could be plated with dendrite-free morphology up to 5 mAh cm−2. • The Li || Cu cell with the ZnO/C@SE exhibited stable cycle performance. • The Li-S battery with the ZnO/C@SE showed outstanding cycle performance. [Display omitted] Lithium metal has great attraction as an ultimate anode material due to its extremely high capacity of 3860 mAh g−1 and the lowest electrochemical potential (−3.04 V vs SHE). However, Li dendrite growth and corresponding poor cyclability still obstruct the practical use of Li metal anodes. Here, we report the yolk shell structured zinc oxide/carbon sphere coated polyethylene separator (ZnO/C@SE) to suppress Li dendrite growth and improve the cycle life of Li metal anodes. Initially ZnO could be lithiated first to form LiZn and Li 2 O. The lithiated ZnO and carbon layer on a polyethylene separator not only enables uniform surface current flows at an interface between a Li metal anode and an electrolyte, but also efficiently utilizes electrochemically inactive "dead" Li. With those synergistic advantages, Li could be deposited with dendrite-free morphology with the areal capacity up to 5 mAh cm–2. The Li || Cu cell with ZnO/C@SE shows outstanding performance even at a high current density of 2 mA cm–2 with a high capacity of 2 mAh cm–2 over 100 cycles. Furthermore, the Li–S battery with the ZnO/C@SE exhibits significant improvement in cycle performance at 0.2 C over 300 cycles. [ABSTRACT FROM AUTHOR]