Synchronous Carbon Coating and Prelithiation for Achieving Synergistic Lithium Compensation and Silicon Grain Size Modulation on Silicon Monoxide Anodes

Le résumé fourni par la source

Abstract Silicon monoxide (SiOx, x ≈ 1) possesses a specific capacity sixfold higher than graphite anodes, rendering it one of the most commercially viable anode candidates. Nevertheless, the low initial Coulombic efficiency (ICE) is one of the main factors hindering large-scale commercial application. In the solid-state prelithiation process, elevating the treatment temperature can effectively improve the prelithiation level of the material, while it also accelerates the growth of silicon grains and deteriorates the cycling performance. Hence, a synchronous asphalt carbonization and LiH prelithiation strategy was conducted, which can inhibit Si grain coarsening by absorbing the concentrated heat released from the LiH prelithiation during the asphalt carbonization process. Meanwhile, serving as a carbon precursor, asphalt forms an in situ carbon layer coating the Si or LixSiOy cores. The composite carbon layer structure effectively improves the electrical conductivity of the material, accelerates swift Li+ transport, enhances structural rigidity, and alleviates volume expansion. The synchronous carbon coating and prelithiation SiO (Syn-Li-SiO@C) electrode delivers an excellent ICE of 91.1% and a high reversible specific capacity of 1300 mAh g−1, while maintaining a superior capacity retention of 92.2% after 100 cycles. This work provides a viable route for addressing Si grain coarsening in the solid-state prelithiation of the SiO anode.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.