Meng Qinghai, Li Ge, Yue Junpei, Xu Quan, Yin Ya-Xia, Guo Yu-Guo
CAS Key Laboratory of Molecular Nanostructure and Nanotechnology, CAS Research/Education Center for Excellence in Molecular Sciences, Beijing National Laboratory for Molecular Sciences (BNLMS) , Institute of Chemistry, Chinese Academy of Sciences (CAS) , Beijing 100190 , P. R. China.
University of Chinese Academy of Sciences , Beijing 100049 , P. R. China.
ACS Appl Mater Interfaces. 2019 Sep 4;11(35):32062-32068. doi: 10.1021/acsami.9b12086. Epub 2019 Aug 21.
Silicon-based electrodes are promising and appealing for futuristic Li-ion batteries because of their high theoretical specific capacity. However, massive volume change of silicon upon lithiation and delithiation, accompanied by continual formation and destruction of the solid-electrolyte interface (SEI), leads to low Coulombic efficiency. Prelithiation of Si-based anode is regarded as an effective way for compensating for the loss of Li in the first discharging process. Here, a high-performance lithiated SiO anode was prepared by using a controllable, efficient, and novel prelithiation strategy. The lithiation of SiO is homogeneous and efficient in bulk due to well-improved Li diffusion in SiO. Moreover, the in situ formed SEI during the process of prelithiation reduces the irreversible capacity loss in the first cycle and thus improves the initial Coulombic efficiency (ICE). Half-cells and full cells based on the as-prepared lithiated SiO anode prominently increase the ICE from 79 to 89% and 68 to 87%, respectively. It is worth mentioning that the homogeneously lithiated SiO anode achieves stable 200 cycles in NCM622//SiO coin full cells. These exciting results provide applicable prospects of lithiated SiO anode in the next-generation high-energy-density Li-ion batteries.
由于具有高理论比容量，硅基电极对未来的锂离子电池而言很有前景且颇具吸引力。然而，硅在锂化和脱锂过程中会发生大量体积变化，同时伴随着固体电解质界面（SEI）的持续形成与破坏，导致库仑效率较低。硅基负极的预锂化被视为补偿首次放电过程中锂损失的有效方法。在此，通过使用一种可控、高效且新颖的预锂化策略制备了一种高性能的锂化SiO负极。由于Li在SiO中的扩散得到显著改善，SiO的锂化在整体上是均匀且高效的。此外，预锂化过程中原位形成的SEI减少了首次循环中的不可逆容量损失，从而提高了初始库仑效率（ICE）。基于所制备的锂化SiO负极的半电池和全电池分别将ICE从79%显著提高到89%以及从68%提高到87%。值得一提的是，均匀锂化的SiO负极在NCM622//SiO硬币全电池中实现了200次稳定循环。这些令人振奋的结果为锂化SiO负极在下一代高能量密度锂离子电池中的应用提供了前景。
