Peng Xiaoli, Yuan Long, Li Shilan, Jing Shengdong, Tian Yaozhu, Luo Zhu, Zhang Yufei, Fan Haosen
College of Materials Science and Metallurgy Engineering, Guizhou University, Guiyang 550025, China.
College of Materials Science and Metallurgy Engineering, Guizhou University, Guiyang 550025, China.
J Colloid Interface Sci. 2025 Dec 15;700(Pt 2):138455. doi: 10.1016/j.jcis.2025.138455. Epub 2025 Jul 16.
Lithium‑sulfur batteries (LSBs) have attracted much attention due to their high theoretical energy density (2600 Wh kg) and low cost of sulfur cathodes. However, their practical application is hindered by the significant polysulfide shuttle effect and sluggish redox kinetics. To address these challenges, a Co-NC/NbO heterostructure was successfully prepared through high-temperature annealing of a ZIF-67 precursor followed by hydrothermal growth of NbO nanocrystals on the surface of Co-embedded and N-doped carbon polyhedrons (Co-NC). The unique structure features a hierarchical conductive framework with uniformly dispersed NbO nanoparticles and defect-rich carbon matrix, which synergistically enhances sulfur utilization and ion diffusion. Numerous dangling bonds and defective sites exist on the NbO surfaces, and its Lewis acidic site (Nb) can inhibit the solvation and shuttling of LiPSs through strong chemical interactions with the S atoms of polysulfides via Nb-O-S bonds. The catalytic and adsorption mechanisms were explained by density functional theory (DFT) calculations and experimental results. Consequently, LSBs cells equipped with Co-NC/NbO modified separators demonstrated exceptional electrochemical performance with a rate capability that provides a reversible capacity of 761.8 mAh g at 3 °C. The composite of MOF-derived hollow carbon polyhedra decorated with NbO nanoparticles ensured fast electron transfer, achieving a reversible capacity of 731.4 mAh g after 500 cycles at 1C and 501.6 mAh g after 1000 long cycles at 2C, with a capacity decay rate of only 0.03 % per cycle. Excellent electrochemical performance was maintained with a high sulfur loading cycling performance of 5 mg cm at a low electrolyte/sulfur condition of 7 μL mg. This work provides new insights into the development of high energy density LSBs and the advancement of next generation energy storage systems through precise electronic structure design at the heterojunction interface.
锂硫电池（LSBs）因其高理论能量密度（2600 Wh kg）和硫阴极低成本而备受关注。然而，其实际应用受到显著的多硫化物穿梭效应和缓慢的氧化还原动力学的阻碍。为应对这些挑战，通过对ZIF-67前驱体进行高温退火，然后在嵌入钴和氮掺杂的碳多面体（Co-NC）表面水热生长NbO纳米晶体，成功制备了Co-NC/NbO异质结构。独特的结构具有分层导电框架，其中NbO纳米颗粒均匀分散且碳基质富含缺陷，协同提高了硫利用率和离子扩散。NbO表面存在大量悬空键和缺陷位点，其路易斯酸位点（Nb）可通过与多硫化物的S原子通过Nb-O-S键形成强化学相互作用，抑制LiPSs的溶剂化和穿梭。通过密度泛函理论（DFT）计算和实验结果解释了催化和吸附机制。因此，配备Co-NC/NbO改性隔膜的LSBs电池表现出优异的电化学性能，在3°C下具有倍率性能，提供761.8 mAh g的可逆容量。用NbO纳米颗粒修饰的MOF衍生的中空碳多面体复合材料确保了快速电子转移，在1C下500次循环后实现了731.4 mAh g的可逆容量，在2C下1000次长循环后实现了501.6 mAh g的可逆容量，容量衰减率仅为每循环0.03%。在7 μL mg的低电解质/硫条件下，以5 mg cm的高硫负载循环性能保持了优异的电化学性能。这项工作通过在异质结界面进行精确的电子结构设计，为高能量密度LSBs的开发和下一代储能系统的进步提供了新的见解。
