Silicon negative electrodes for lithium-ion batteries: challenges, advances, and future prospects

Due to its remarkably high theoretical capacity, silicon has attracted considerable interest as a negative electrode material for next-generation lithium-ion batteries (LIBs). Nonetheless, its actual application is hindered by numerous problems, including considerable volumetric expansion, unstable solid electrolyte interface (SEI), irreversible capacity loss, and mechanical deterioration. This mini-review offers a systematic examination of the essential concepts of LIBs, succeeded by an in-depth analysis of the primary constraints related to silicon-based negative electrodes. Recent advancements in material design, encompassing nanostructured silicon, silicon-carbon composites, and silicon alloys, are analysed in conjunction with progress in electrolyte engineering intended to address SEI instability. Advancements in binder technology and prelithiation techniques are examined as essential enablers of enhanced cycle stability and coulombic efficiency. We discuss advanced characterisation techniques that provide fundamental insights into the electrochemical and mechanical properties of silicon electrodes. To connect basic research to commercial feasibility, we delineate potential research avenues, including scalable production, complex electrolyte and binder systems, innovative material designs, and sustainability factors. This mini-review evaluates current advancements and guides future approaches for silicon-based negative electrodes in high-performance LIBs.