Environmental waste-derived dual heteroatom-rich sustainable carbon as anodes for Li- and Na-ion batteries

In this study, we demonstrate the use of dual heteroatom-doped (i.e., N- and S-doped) porous carbon derived from the filters in cigarette butts, which are categorized as solid environmental waste. We use a facile, sustainable, and inexpensive method and green chemical activation for application in LIBs and SIBs. The carbon prepared by activating melamine is highly porous with rich and mesopores along with a high Brunauer-Emmett-Teller (BET) surface area (815.8 m² g⁻¹) and pore volume (0.404 cm³ g⁻¹). The favorable textural properties, such as enlarged interlayer d-spacing, edge defects, electrochemically active N and S functionalities, and high electronic conductivity, make this porous carbon an attractive candidate for both Li- and Na-ion storage applications. The porous carbon delivered high capacities of ∼872 mAh g⁻¹ and 289 mAh g⁻¹ at 500 mA g⁻¹ when employed as anodes for LIBs and SIBs, respectively. The high-performance porous carbon materials developed via the proposed green and sustainable approach can be applied to advanced energy storage systems.