Cost‑effective anode materials of nanostructure SnO₂ adhered to Sterculia foetida fruit shell-derived natural porous carbon for sustainable lithium-ion batteries

Sterculia foetida (SF), often known as Samrong, is a fruiting plant in Thailand. Its fruit shell as raw material contains a high level of fiber, which was converted into porous carbon (SF-PC) via facile KOH activation. This product was subsequently composited with SnO₂ to enhance its specific capacity. Microstructure observations reveal that the SF-PC, which has a high surface area (1942 m² g⁻¹), contains primarily micropores and mesopores. On the porous carbon surface of the synthesized nanocomposite, SnO₂ nanoparticles were distributed uniformly. In electrochemical tests, the SnO₂/SF-PC electrode could maintain a specific capacity of 510.71 mAh g⁻¹ at 0.1 A g⁻¹ after 300 cycles, which was higher than bare SF-PC (336.51 mAh g⁻¹). Also, this electrode performed with excellent cyclic stability over 500 cycles at high current stage. The lithiation–delithiation and side reactions of the electrode were demonstrated, whereas this electrode possessed a low internal resistance and great diffusion kinetics. Their attractive anode characteristics of having a distinct structure, high storage capability, being low cost and environmentally friendly, and having good cycling stability indicate that they can serve as highly efficient and effective anode materials in sustainable lithium-ion batteries.