Peng Bo, Bao Weizhai, Sun Kaiwen, Xiao Jin
School of Metallurgy and Environment, Central South University, Changsha 410083, China.
School of Chemistry and Materials Science, Nanjing University of Information Science and Technology, Nanjing 210044, China.
Nanomaterials (Basel). 2025 May 2;15(9):690. doi: 10.3390/nano15090690.
Prelithiation has been widely accepted as one of the most promising strategies to compensate for the loss of active substance and to improve the initial Coulombic efficiency in silicon-based anodes for advanced high-energy-density batteries. But because of their unstable solid electrolyte interface (SEI) layer and low initial Coulombic efficiency, they expand in volume during prelithiation and react with moisture, which makes commercialization a difficult process. Herein, we have developed a strategy using lithium bis(fluorosulfonyl)imide (LiFSI) treatment to eliminate redundant lithium and generate LiF-based inorganic compounds on the surface of the prelithiated electrode. Such method not only reduces the reactiveness of the prelithiated anode but also enhances the ionic conductivity of the SEI. The rich LiF surface works as an artificial SEI, and according to electrochemical evaluation, the initial Coulombic efficiency of the prelithiated silicon anode treated with LiFSI can reach 92.9%. This technique not only increases the battery's energy density but also its cycle stability, resulting in superior capacity retention and a longer cycling life.
预锂化已被广泛认为是补偿活性物质损失并提高先进高能量密度电池硅基负极初始库仑效率的最有前景的策略之一。但由于其不稳定的固体电解质界面（SEI）层和较低的初始库仑效率，它们在预锂化过程中会发生体积膨胀并与水分发生反应，这使得商业化过程变得困难。在此，我们开发了一种使用双（氟磺酰）亚胺锂（LiFSI）处理的策略，以消除多余的锂并在预锂化电极表面生成基于LiF的无机化合物。这种方法不仅降低了预锂化负极的反应活性，还提高了SEI的离子电导率。富含LiF的表面起到了人工SEI的作用，根据电化学评估，用LiFSI处理的预锂化硅负极的初始库仑效率可达92.9%。该技术不仅提高了电池的能量密度，还提高了其循环稳定性，从而实现了卓越的容量保持率和更长的循环寿命。
