Ultrafine Nanocrystals SnS2 Confined on the Inner Wall of Hollow Mesoporous Carbon Nanospheres with Hybrid Storage Mechanism for High‐Performance Li+/Na+ Batteries

Abstract SnS 2 has a large volume change and unstable structure during charging and discharging, seriously hindering its application in lithium‐ion batteries (LIBs) and sodium‐ion batteries (SIBs). Herein, ultrafine nanocrystals SnS 2 are confined to the inner wall of hollow mesoporous carbon nanospheres (HMCNS) by one‐step hydrothermal reaction for the first time, forming a special hollow structure with buffer volume effect. After a series of electrochemical analyses, the composite not only displays preeminent long cyclic stability and excellent rate performance, but also shows a hybrid storage mechanism. When used as the anode for LIBs, SnS 2 @HMCNS maintains a superior capacity of 755 mAh g −1 after 100 cycles at 0.1 A g −1 and at 2 A g −1 , the capacity is 547.8 mAh g −1 . Besides, adopted as the anode of SIBs, SnS 2 @HMCNS exhibits a capacity of 254.5 mAh g −1 after 1000 cycles at 1 A g −1 , far exceeding that of pure SnS 2 . The outstanding electrochemical performance is owed to the ultrafine nanocrystals SnS 2 adhered to the inner wall of HMCNS, which prevents stacking and increases the active lithium/sodium storage sites. Additionally, the large cavity of HMCNS can provide sufficient buffer space for SnS 2 in the process of ion embedding/stripping, optimizing the structural stability of the composite.