Carbon‐Coated SnS Nanosheets Supported on Porous Microspheres as Negative Electrode Material for Sodium‐Ion Batteries
Suning Gao, Liangtao Yang, Zaichun Liu, Jie Shao, Qunting Qu, Masud Hossain, Yuping Wu, Philipp Adelhelm, Rudolf Holze
Abstract
SnS has outstanding theoretical capacity and is a promising electrode material for sodium‐ion batteries. However, intrinsic low conductivity and huge volume changes upon sodium extraction/insertion limit its application. Herein, hierarchical hollow carbon spheres covered with S,N‐doped carbon‐coated SnS nanosheets synthesized by a multistep process are reported, including a hard sacrificial template, hydrothermal reaction, and annealing treatment. The prepared C@SnS@C samples are characterized by X‐ray diffraction, scanning electron microscopy, high‐resolution transmission electron microscopy, and X‐ray photoelectron spectroscopy. The nanosized SnS provides capacity; S,N‐doped carbon coating protects the integrated structure. Consequently, due to the compositional and structural merits, the optimized electrode has a high specific capacity of around 420 mAh g −1 at 0.2 A g −1 , high rate performance (200 mAh g −1 at 10 A g −1 ), and good cycling stability with 95% (i.e., 305 mAh g −1 at 0.5 A g −1 ) of the initial capacitance after 100 cycles. Kinetic analyses reveal that a substantial capacitive contribution results in better rate performance of the C@SnS@C electrode.