Polysulfide-derived anion heterogeneous interfaces engineering to facilitate high-efficiency sodium ion storage

• Main Authors: Wang, Jian, Cui, Jing, Li, Zhaojin, Zhang, Di, Sun, Huilan, Wang, Huan, Wang, Qiujun, Woo, Haw Jiunn, Wang, Bo
• Format: Article
• Published: Elsevier 2023
• Subjects: QD Chemistry; TP Chemical technology
• Online Access: http://eprints.um.edu.my/38307/

Poor structural stability and inherent low conductivity of the transition metal polysulfides often trigger continuous capacity decay. Here, an anionic heterogeneous modification engineering of the VS4 system is ach-ieved by employing one-step strategy. The prepared layered V1.11S2/V1.13Se2/C heterostructure (VSSe/C) ex-hibits expanded layer distance (5.926 A) and improved metallicity properties. Furthermore, the constructed built-in electric field achieves lower free energy and effective adsorption of reaction products. Resultantly, when applied to the sodium-ion battery anode, a high specific capacity of 784.9 mA h g-1 is achieved with 500 cycles at a current density of 2 A g-1. Impressively, a high capacity retention of 553.2 mA h g-1 is performed after 1000 cycles at 10 A g(-1), which is significantly better than the unmodified VS4 electrode. Additionally, the assembled sodium ion capacitor exhibits excellent energy densities of 89.1 W h kg(-)1 at 380 W kg(-1) and an ultra-high capacity retention rate of 96.6% over 2000 cycles at a high power density of 3800 W kg(-1). Ex-situ XRD and XPS results reveal a stable disulfide/selenide conversion process, and no intermediate polysulfide formation. The design of anionic heterostructures using polysulfide derivatives may provide a reference for improving the structural properties of anion-rich based anode materials.