Large Interlayer Spacing of Few-Layered Cobalt–Tin-Based Sulfide Providing Superior Sodium Storage
Shuming Dou, Jie Xu, Hirbod Maleki Kheimeh Sari, Hong‐Hui Wu, Junhua Hu, Yaohui Zhang, Linlin Fan, Dongbin Xiong, Wei Zhou, Yanan Chen, Xifei Li
Abstract
Mixed transition metal sulfides (MTMSs) have been regarded as a potential anode material for sodium-ion batteries (SIBs) due to their high reversible specific capacity. Herein, nanoflower-like few-layered cobalt–tin-based sulfide (F-CoSnS) with a large interlayer spacing is synthesized via a facile route for superior sodium storage. The growth mechanism of this unique F-CoSnS is systematically studied. Such distinctive nanostructured engineering synergistically combines a broad interlayer spacing (∼ 0.85 nm), the functionalities of few (2–3) layers, and the introduction of heterogeneous metal atoms, reducing the ion diffusion energy barrier for high-efficiency intercalation/deintercalation of Na+ ions, as revealed by density functional theory (DFT) calculations. With further incorporation of a three-dimensional (3D) conductive network, the F-CoSnS@C electrode shows a large sodium storage capacity (493.4 mAh g–1 at 50 mA g–1), remarkable rate capability (316.1 mAh g–1 at 1600 mA g–1), and superior cycling stability (450 mAh g–1 at 50 mA g–1 with 91.2% capacity retention, 0.044% fading rate per cycle, and approximately 100% Coulombic efficiency after 200 cycles). This work demonstrates that the few-layered ternary MTMSs are highly applicable for the development of advanced SIB anode materials with high performance.