Carbon Nanofibers from Renewable Sources: A Green Route to Advanced Energy Storage Materials

The continuous increase in global energy consumption is primarily driven by the rapid expansion of urban areas and acccelerated industrialization. This has led to a need for the integration of renewable energy systems, aimed at enhancing sustainability, alongside the demand for more efficient technologies for energy harvesting and storage. In this context, supercapacitors and batteries have gained vital importance, as they can store and swiftly release energy with high efficiency to meet the needs of electric mobility, renewable energy integration, and advanced electronic devices. A continuous increase in energy demand highlights the need for the sustainability of the materials used in their construction, but currently, these devices are mainly prepared from nonrenewable or toxic materials. In this direction, the search for green alternatives using natural and abundant materials, such as carbon-based nanofibers, has gained prominence. Carbon-based nanofibers present remarkable electrical and mechanical properties, combined with high surface area and porosity. Moreover, their carbonaceous nature facilitates integration into circular economy frameworks. Techniques such as electrospinning and solution blow spinning (SBS) are effective for producing carbon fibers at both micro- and nanoscale, making them well-suited for energy storage applications. Accordingly, this review explores recent developments in carbon nanofibers derived from renewable sources and evaluates their potential performance as advanced materials for energy storage applications, particularly supercapacitors and batteries.