Pacific Northwest National Laboratory, 902 Battelle Boulevard Richland, WA 99354, USA.
Nanoscale. 2018 Dec 20;11(1):348-355. doi: 10.1039/c8nr08461k.
Alloy-based nanostructure anodes have the privilege of alleviating the challenges of large volume expansion and improving the cycling stability and rate performance for high energy lithium- and sodium-ion batteries (LIBs and SIBs). Yet, they face the dilemma of worsening the parasitic reactions at the electrode-electrolyte interface and low packing density for the fabrication of practical electrodes. Here, pomegranate Sb@C yolk-shell microspheres were developed as a high-performance anode for LIBs and SIBs with controlled interfacial properties and enhanced packing density. Although the same yolk-shell nanostructure (primary particle size, porosity) and three-dimensional architecture alleviated the volume change induced stress and swelling in both batteries, the SIBs show 99% capacity retention over 200 cycles, much better than the 78% capacity retention of the LIBs. The comparative electrochemical study and X-ray photoelectron spectroscopy characterization revealed that the different SEIs, besides the distinct phase transition mechanism, played a critical role in the divergent cycling performance.
基于合金的纳米结构阳极具有缓解体积膨胀挑战、提高高能锂离子和钠离子电池（LIBs 和 SIBs）的循环稳定性和倍率性能的优势。然而，它们面临着电极-电解质界面副反应恶化和实际电极制造中低堆积密度的困境。在这里，石榴 Sb@C 核壳微球被开发为用于 LIBs 和 SIBs 的高性能阳极，具有可控的界面特性和增强的堆积密度。尽管具有相同的核壳纳米结构（粒径、孔隙率）和三维结构缓解了两种电池中由体积变化引起的应力和肿胀，但 SIBs 在 200 次循环后保持了 99%的容量，明显优于 LIBs 的 78%的容量保持率。比较电化学研究和 X 射线光电子能谱表征表明，不同的 SEI 除了明显的相变机制外，在不同的循环性能中起着关键作用。
