Room temperature sodium–sulfur (RT Na-S) battery with high theoretical energy density and low cost has spurred tremendous interest, which is recognized as an ideal candidate for large-scale energy storage applications. However, serious sodium polysulfide shutting and sluggish reaction kinetics lead to rapid capacity decay and poor Coulombic efficiency. Recently, catalytic materials capable of adsorbing and catalyzing the conversion of polysulfides are profiled as a promising method to improve electrochemical performance. In this review, the research progress is summarized that the application of catalytic materials in RT Na-S battery. For the role of catalyst on the conversion of sulfur species, specific attention is focused on the influence factors of reaction rate during different redox processes. Various catalytic materials based on lightweight and high conductive carbon materials, including heteroatom-doped carbon, metals and metal compounds, single-atom and heterostructure, promote the reaction kinetic via lowered energy barrier and accelerated charge transfer. Additionally, the adsorption capacity of the catalytic materials is the key to the catalytic effect. Particular attention to the interaction between polysulfides and sulfur host materials is necessary for the exploration of catalytic mechanism. Lastly, the challenges and outlooks toward the desired design of efficient catalytic materials for RT Na-S battery are discussed.

A three-dimensional flower-like NiCo₂S₄ formed by two-dimensional nanosheets is synthesized by a facile hydrothermal method and utilized as the anode for sodium-ion batteries. Studies have shown that materials can achieve the best performance under the ether-based electrolyte system with voltage ranging from 0.3 to 3 V, which could effectively avoid the dissolution of polysulfides and over-discharge of the material. Here, sodium storage mechanism and charge compensation behaviors of this ternary metal sulfide are comprehensively investigated by ex situ X-ray diffraction. Moreover, ex situ Raman spectra, ex situ X-ray photoelectron spectroscopy and transmission electron microscopy measurements are used to related tests for the first time. Additionally, quantitative kinetic analysis unravels that sodium storage partially depends on the pseudocapacitance mechanism, resulting in good specific capacity and excellent rate performance. The initial discharge capacity is as high as 748 mAh·g^-1 at a current density of 0.1 A·g^-1 with the initial coulomb efficiency of 94%, and the capacity can still maintain at 580 mAh·g^-1 with the Coulomb efficiency close to 100% after following 50 cycles. Moreover, by the long cycle test at a high current density of 2 A·g^-1, the capacity can still reach at 376 mAh·g^-1 after over 500 cycles.