Encapsulation of SnO2 by carbon nanotubes and WS2 to form high-performance lithium-ion batteries materials

Abstract

Optimizing the structure of materials has proven to be an efficient solution for improving the electrochemical performance of lithium-ion batteries. In this work, SnO2-WS2-CNTS (SWC) ternary composites were prepared by hydrothermal and ball milling methods to first obtain SnO2-WS2 mixture, which was then embedded on CNTS to form a special multi-level structure. Due to the special 2D structure of transition metal sulfide WS2 and CNTS, the de-intercalation speed of lithium ions is greatly increased and the inherent particle aggregation phenomenon of SnO2 is weakened. The three materials show their advantages while compensating for each other's disadvantages, forming an interesting synergistic effect which results in extremely stable anode materials. At 0.2Ag-1, the capacity of SWC reaches 930.71 mAhg-1 after 100 cycles, and reaches 1043 mAhg-1 after 1000 cycles at 1.0Ag-1. It is worth noting that after multiple cycles, SWC still exhibits an extremely stable state in the SEM image. The above results confirm that the special structure of SWC leads to excellent electrochemical performance, and its simple preparation method makes it a potential leading battery anode material in the future.