Unordered vacancies provide rapid migration pathways for sodium ion insertion/extraction in copper-deficient ternary Cu4Bi4Se9
作者：X Han，GP Liu, WQ Kong, LZ Zhao, WR Li, F Ilyas, HY Zhu, JC Guo, ZS Wen*
關鍵字：Sodium-ion battery; AnthodeMetal chalcogenides; Rate performanceLong cycle life
論文來源：期刊
具體來源：Chemical Engineering Journal
發表時間：2024年
Sodium-ion batteries based on binary bismuth selenides exhibit poor rate performance due to their intrinsic low conductivity, typically requiring nanoscale structuring to optimize rate capability. However, nanoscaling of materials is not conducive to the preparation of high-energy-density electrode materials. In the novel ternary Cu4Bi4Se9 electrode, the disordered vacancy structure formed by Cu with an occupancy less than 1 facilitates rapid sodium ion migration. Density functional theory (DFT) calculations demonstrate the ultra-high electron conductivity of Cu4Bi4Se9, providing the driving force for sodium ion migration. Meanwhile, Cu4Bi4Se9 exhibits stronger sodium ion capture capability compared to Bi2Se3. The micron-sized Cu4Bi4Se9 electrode exhibits a reversible capacity of 237.5 mAh g?1 after 10,000 cycles at an ultra-high density of 60C. This micron-sized Cu4Bi4Se9 offers a new approach to address the contradiction between high capacity and excellent rate performance, which is of great significance for breaking the excessive reliance on nanostructure configuration for the next generation of high-capacity anode materials.
https://authors.elsevier.com/a/1k1Iy4x7R2kQqJ
https://doi.org/10.1016/j.cej.2024.157214