Short rod-like NiCoSe2 binary-metal selenide nanomaterials of carbon-coated as high-performance anode for sodium-ion batteries.

Due to the synergistic effect between multiple elements, bimetallic selenides materials can generate more active sites in the electrochemical reaction process, which can significantly improve the electrical conductivity for anode materials. Nevertheless, it is liable to produce severe volume expansion and exhibit the poor electrochemical performance. Therefore, we decided to modify it by carbon cladding; the carbon-coated short rod-like NiCoSe₂ (NiCoSe₂@C) nanomaterials were synthesized through facile hydrothermal reaction, dopamine coating, and carbonization process. It was found that the as-prepared NiCoSe₂@C nanomaterial exhibits stable structure, outstanding cycling stability, and high pseudocapacitive contribution. Specifically, the specific charging capacity is 370.6 mAh g⁻¹ (0.1 A g⁻¹, 100 cycles) and 304.8 mAh g⁻¹ (2 A g⁻¹, 600 cycles) as anode when used for SIBs. Comparing with the pure NiCoSe₂ nanomaterial, the construction of carbon layer can mitigate the effect of volume expansion and reduce the generation of adverse materials, thus enhancing the cycling stability. [ABSTRACT FROM AUTHOR]