High-Performance All-Solid-State Batteries Enabled by Dual-Functional LiH-Dehydrogenation-Driven Prelithiation of Silicon Anodes

Abstract Silicon (Si) is regarded as one of the most promising anode materials for lithium-ion batteries (LIBs), owing to its superior theoretical specific capacity and safe working potential. However, its practical application is hindered by the low initial coulombic efficiency (ICE) and severe volume expansion. Herein, we propose an alternative solid prelithiation strategy driven by the dehydrogenation of lithium hydride (LiH), where Li7Si3 and Li22Si5 alloys are successfully synthesized through precise process control. Notably, LiH plays dual roles not only providing additional Li+ but also establishing a strong interfacial electric field that facilitates Li+ migration. Consequently, the 1Si-6LiH and 1Si-7LiH anodes achieve high ICE values of 84.53 and 95.87%, respectively. Full cells integrated with a LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode exhibit low volume strain and a high-capacity retention of 91.5% after 400 cycles at 0.5 C. Moreover, the 1 Ah-designed pouch cell exhibits favorable electrochemical stability, retaining a capacity of 0.5 Ah even after 100 cycles at a rate of 0.33 C. This work presents a promising strategy for developing high-rate and long-cycle-life Si-based anode materials.