Integrated prelithiation and SEI engineering for high-performance silicon anodes in lithium-ion batteries

Abstract Improving the initial Coulombic efficiency (ICE) of silicon anodes in lithium-ion batteries is a key challenge for enhancing their performance. Traditional prelithiation methods, such as using lithium naphthalenide (Li-Naph), are limited by the low lithiation potential of crystalline silicon, making them less effective for commercial applications. This study demonstrates that amorphous silicon anodes, with a higher lithiation potential, can be effectively prelithiated using Li-Naph. This prelithiation process also forms a robust solid electrolyte interphase (SEI), which significantly enhances the anode's cycling stability and overall battery performance. The prelithiated silicon anodes achieved a remarkable ICE improvement from 74.8% to 97.2% in full cell tests. Furthermore, 27 mAh pouch cells exhibited excellent long-cycle stability and low-temperature performance, retaining 90.1% of capacity after 800 cycles at 1C. These findings highlight the potential for scalable prelithiation methods and open new avenues for advancing silicon anode technology in next-generation batteries.