Abstract:

With the increasing consumption of lithium resources and the improvement of renewable energy-based modern electric system's requirements for large-scale energy storage equipment in the context of pursuing carbon neutrality, sodium ion batteries have become the hot spot of electrochemical energy engineering research at present. Using thioacetamide as sulfur source and SnCl₂·2H₂O as tin source, a series of three-dimensional flower-like SnS₂ with nano-porous lamellae and open frameworks were prepared by a mild hydrothermal method. The physical and electrochemical properties such as morphology, structure and specific surface area of the flower-like SnS₂ were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, specific surface analysis and electrochemical performance test. The results show that the SnS₂ prepared with a hydrothermal time of 4 h （4 h-SnS₂） processes the best crystallinity and uniform morphology. The nano-lamellae composing the flower-like structure are thin and of a large specific surface area （196.39 m²/g）, which is beneficial for shortening the Na⁺ transport path, and facilitating the full contact to electrolyte and the transfer of electrons between phase interfaces. Thus, the sodium storage performance of SnS₂ can be improved. The specific discharge capacity of 4 h-SnS₂ is maintained at 526.8 （mA·h）/g after 150 cycles at a current density of 1 A/g. This work provides basic fundamental data for the large-scale preparation and research of sodium ion batteries with SnS₂ as anode material.

Key words: carbon neutrality, renewable energy, energy storage battery, sodium ion battery, anode material, SnS₂, flower-like structure, rate capability, cycling performance