Strategies Toward the Production of Nanoporous <i>SiO_x</i>/C Anodes from the Sustainable Diatom‐<i>SiO</i>₂ for Li‐Ion Batteries: A Comparative Study of Different Carbon Amounts

Gaarud, Anders ; Thangaian, Kesavan ; Alonso-Sánchez, Pedro ; Blanco, Maria Valeria

Resumen: Nanostructured SiOx/C composites are promising candidates for high energy density anodes with extended lifespan in next-generation Li-ion batteries (LIBs). However, integrating sustainable precursors for the synthesis of high performance SiOx/C negative electrodesremains a key challenge. In this study, nanoporous SiO2 derived from the shells of industrially cultured diatom microalgae is successfully used as a template for synthesizing SiOx via the magnesiothermic reduction reaction (MgTR), while the effectiveness of different carbon coating (CC) strategies to produce diatom-SiOx/C from glucose as carbon precursor is thoroughly analyzed. Notably, the original nanostructure of the diatom-SiO2 frustule is preserved throughout the synthesis process, and it is demonstrated that increasing the heating ramp during MgTR enhances the Si yield, leading to a significant increase in specific capacity of the anodes from 1064 mAh.g−1 (2 °C/min−1) to 1846 mAh.g−1 (20 °C/min−1). A comparative analysis of three synthesis pathways for producing diatom-SiOx/C composites: 1) MgTR of diatom-SiO2 followed by CC, 2) CC of diatom-SiO2 followed by MgTR, and 3) simultaneous reduction of diatom-SiO2 and glucose precursor, revealed that pathway (1) is most effective for producing highcapacity diatom-SiOx/C anodes. These findings provide key enablers for developing sustainable SiOx/C anodes of superior electrochemical performance.

Idioma: Inglés

DOI: 10.1002/adsu.202500117

Año: 2025

Publicado en: Advanced Sustainable Systems 9, 5 (2025), 2500117 [9 pp.]
ISSN: 2366-7486

Tipo y forma: Article (Published version)