Hydrothermal synthesis of NiSe2 octahedral structure and sodium ion storage performance

Nowadays, due to the abundant storage resources and low price of sodium, it receives extensive attention in the field of new energy batteries. NiSe2 anode material is the focus of much investigation in the search for Anode materials with promising and stable electrochemical performance and high theoretical specific capacity that have attracted much attention. Its unique nanostructure design is also an important way to improve its electrochemical properties. Therefore, the principal measure of this project is to the preparation of regular octahedral NiSe2 materials by a simple hydrothermal method. And the structure and storage mode of sodium ions is studied by relevant characterization methods. When the current density is 0.1 A g−1, the charge-specific capacity after 100 cycles is 349.8 mAh g−1, and at the current density of 2.0 A g−1, the charge-specific capacity after 500 cycles remains at 299.6 mAh g−1. It is concluded that NiSe2 nanostructure has excellent cycling stability and high specific capacity as an anode material for the sodium ions. When the current density is 0.1, 0.2, 0.5, 1, 2, 5 A g−1, the coulomb efficiency remains about 100%. When the current density is restored to 0.1 A g−1 again, the specific capacity can be restored to 370.3 mAh g−1, and it can reflect excellent ratio performance and good structural stability. The reason for these excellent electrochemical performances is ultimately related to the stable regular octahedral structure and excellent electrical conductivity of NiSe2. As a result of these investigations, suggestions are identified for future research regarding the further study of the excellent electrochemical characteristics of NiSe2 materials.