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

To 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 (SnS _1.5 Se _0.5 ) 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, SnS _1.5 Se _0.5 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 SnS _1.5 Se _0.5 , leading to a pseudocapacitive storage effect that presents a promising potential for high-performance energy storage devices. The study has successfully developed a SnS _1.5 Se _0.5 /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, Na ₃ V ₂ (PO ₄ ) ₃ //SnS _1.5 Se _0.5 /NS-C delivers a high energy density of 176.6 Wh kg ^-1 . In addition, the Na ⁺ storage mechanism of SnS _1.5 Se _0.5 /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.
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