Review on current advancements in silica and their composites for high-performance batteries and supercapacitors

Efficient energy storage devices like batteries and supercapacitors are vital for meeting global energy demands and enabling the transition from fossil fuels to renewable energy. Among the various materials, silica (SiO₂) and its composites have emerged as promising candidates for advanced electrochemical storage owing to their abundance, low cost, and high theoretical capacity. This state-of-the-art review critically examines the synthesis methods, structural modifications, and performance characteristics of SiO₂-based materials with a focus on their use in batteries and supercapacitors. Key synthesis techniques, such as sol-gel, hydrothermal, and pyrolysis, are discussed, emphasizing their role in tuning the morphology, surface area, and porosity to enhance the electrochemical properties. SiO₂‑carbon composites, in particular, show significant promise as anodes, offering improved cyclic stability, reduced volume expansion, and enhanced conductivity. Despite these advances, challenges, such as low initial coulombic efficiency and volume changes, remain. Strategies, such as the incorporation of carbon frameworks and hierarchical structures, have been proposed to address these issues. This review highlights the potential of SiO₂-based anodes for achieving a higher specific capacitance, energy density, and cycle life, offering a comprehensive guide for further research on the development of next-generation energy storage materials.