Promoting polysulfide conversion by catalytic of ZnSe nanoparticles for room-temperature sodium-sulfur battery

Although room temperature sodium-sulfur (RT/Na-S) battery has been acclaimed as one of the most promising among the next generation of energy storage technologies, their commercial practicability is still challenged because of the shuttle effect of sodium polysulfides (NaPSs) as well as the slow sulfur (S) cathode redox kinetics. Here, metal selenides (ZnSe) nanoparticles loaded on nitrogen-doped carbon (ZnSe/NC) are elaborately designed and synthesized to serve as the S host for RT/Na-S battery. The ZnSe/NC can accommodate a high S loading and facilitate ion transport. Meanwhile, ZnSe nanoparticles can promote the conversion of long-chain NaPSs into short-chain NaPSs. During this process, they can exert a strong adsorption effect on NaPSs through chemical bonds (Zn S). The superiority of the S@ZnSe/NC electrode is harnessed in the assembly of RT/Na-S battery, presenting remarkable capacity performance and stable cycling (retains 720 mAh g −1 after 100 cycles at 0.1 A g −1 and 400.8 mAh g −1 after 1300 cycles at 1.0 A g −1 .). This work offers a feasible approach to prepare metal selenide catalysts for high-performance RT/Na-S battery. A novel ZnSe nanoparticle loaded on nitrogen-doped carbon (ZnSe/NC) is synthesized and used as the host in cathode for room-temperature sodium-sulfur battery. The ZnSe/NC exhibits excellent adsorption and catalytic conversion abilities toward sodium polysulfides . The S@ZnSe/NC displays excellent cycling stability with significant reversible capacity for room-temperature sodium-sulfur battery. • A host with ZnSe nanoparticles loaded on a nitrogen-doped carbon is used as the sulfur cathode for RT/Na-S battery. • ZnSe nanoparticles can not only have strong adsorption capacity of NaPSs but also promote the conversion of NaPSs. • The assembled RT/Na-S battery achieves excellent rate performance and long-term cycle performance (1300 cycles).