Designing A Carbon-Encapsulated ZnS/SnS2/SnO2 Heterojunction Secondary Battery Anode Displaying Large Capacity and Good Stability

Abstract

Developing structurally heterostructured anodes with good electrical/ionic conductivity is significant to achieve highperformance sodium-ion batteries. Here, a carbon-encapsulated hollow ZnS/SnS2/SnO2 heterojunction anode is developed, which exhibits excellent Na-storage performance and stability. The ZnS/SnS2/SnO2@C anode shows a large capacity of 612 mAh g-1 after 100 cycles with a high Coulombic efficiency. After 400 cycles at 1.0 A g-1 , capacity keeps 471 mAh g-1 , and good temperature tolerance is also achievable retaining 247 mAh g-1 after 130 cycles at -10 °C. The in situ Raman spectroscopy and in situ X-ray diffraction verify high charge-discharge reversibility, indicating this rational design of the carbonencapsulated hollow sulfide/oxide heterostructure could be a promising approach for developing high-performance energystorage composites.