School of Materials Science and Engineering, Hainan Institute, Wuhan University of Technology, Wuhan, 430070, P. R. China.
Hainan Institute, Wuhan University of Technology, Sanya, 572000, P. R. China.
ChemSusChem. 2023 May 19;16(10):e202300067. doi: 10.1002/cssc.202300067. Epub 2023 Mar 28.
To better satisfy the increasing demands for electric vehicles, it is crucial to develop fast-charging lithium-ion batteries (LIBs). However, the fast-charging capability of commercial graphite anodes is limited by the sluggish Li insertion kinetics. Herein, we report a synergistic engineering of uniform nano-sized T-Nb O particles on graphite (Gr@Nb O ) with C-O-Nb heterointerfaces, which prevents the growth and aggregation of T-Nb O nanoparticles. Through detailed theoretical calculations and pair distribution function analysis, the stable existence of the heterointerfaces is proved, which can accelerate the electron/ion transport. These heterointerfaces endow Gr@Nb O anodes with high ionic conductivity and excellent structural stability. Consequently, Gr@10-Nb O anode, where the mass ratio of T-Nb O /graphite=10/100, exhibits excellent cyclic stability and incredible rate capabilities, with 100.5 mAh g after 10000 stable cycles at an ultrahigh rate of 20 C. In addition, the synergistic Li storage mechanism is revealed by systematic electrochemical characterizations and in situ X-ray diffraction. This work offers new insights to the reasonable design of fast-charging graphite-based anodes for the next generation of LIBs.
为了更好地满足对电动汽车日益增长的需求，开发快速充电的锂离子电池（LIBs）至关重要。然而，商用石墨负极的快速充电能力受到缓慢的 Li 嵌入动力学的限制。在此，我们报告了在石墨（Gr@Nb O ）上均匀纳米尺寸 T-Nb O 颗粒的协同工程，该颗粒具有 C-O-Nb 异质界面，可以防止 T-Nb O 纳米颗粒的生长和聚集。通过详细的理论计算和配分函数分析，证明了异质界面的稳定存在，这可以加速电子/离子的传输。这些异质界面赋予 Gr@Nb O 负极高离子导电性和优异的结构稳定性。因此，Gr@10-Nb O 负极（其中 T-Nb O /石墨的质量比为 10/100）在超高 20 C 倍率下循环 10000 次后，仍具有出色的循环稳定性和令人难以置信的倍率性能，其容量为 100.5 mAh g 。此外，通过系统的电化学表征和原位 X 射线衍射揭示了协同的 Li 存储机制。这项工作为下一代 LIB 中快速充电石墨基负极的合理设计提供了新的思路。
