High‐Performance Sodium‐Ion Batteries Enabled by 3D Nanoflowers Comprised of Ternary Sn‐Based Dichalcogenides Embedded in Nitrogen and Sulfur Dual‐Doped Carbon

Abstract

AbstractTo make sodium‐ion batteries a realistic option for everyday energy storage, a practicable method is to enhance the kinetics of Na+ reactions through the development of structurally stable electrode materials. This study utilizes ternary Sn‐based dichalcogenide (SnS1.5Se0.5) in the design of electrode material to tackle several issues that adversely hinder the performance and longevity of sodium‐ion batteries. First, the incorporation of Se into the SnS structure enhances its electrical conductivity and stability. Second, the ternary composition restricts the formation of intermediates during the desodiation/sodiation process, resulting in better electrode reaction reversibility. Finally, SnS1.5Se0.5 lowers the diffusion barrier of Na, thereby facilitating rapid and efficient ion transport within the electrode material. Moreover, nitrogen and sulfur dual‐doped carbon (NS‐C) is used to enhance surface chemistry and ionic/electrical conductivity of SnS1.5Se0.5, leading to a pseudocapacitive storage effect that presents a promising potential for high‐performance energy storage devices. The study has successfully developed a SnS1.5Se0.5/NS‐C anode, exhibiting remarkable rate capability and cycle stability, retaining a capacity of 647 mAh g−1 even after 10 000 cycles at 5 A g−1 in half‐cell tests. In full‐cell tests, Na3V2(PO4)3//SnS1.5Se0.5/NS‐C delivers a high energy density of 176.6 Wh kg−1. In addition, the Na+ storage mechanism of SnS1.5Se0.5/NS‐C is explored through ex situ tests and DFT calculations. The findings suggest that the ternary Sn‐based dichalcogenides can considerably enhance the performance of the anode, enabling efficient large‐scale storage of sodium. These findings hold great promise for the advancement of high‐performance energy storage devices for practical applications.