Efficient conversion of non-biodegradable waste into hard carbon as a cost-effective anode for sodium-ion batteries

The possibility of utilizing single-use non-biodegradable materials for secondary usage by converting them into other forms, such as hard carbon, is important because it lowers the long-term environmental hazards associated with these wastes and decreases the manufacture cost of hard carbon by avoiding expensive precursors. Hard carbon has recently attracted interest as a prospective affordable anode for upcoming commercial sodium-ion batteries (SIBs). Herein, we used a simple high-temperature treatment process to convert floral foam into hard carbon for use as a negative electrode in SIBs. The floral foam-derived hard carbon presents a notable electrochemical performance, by maintaining a specific discharge capacity of 88.8% after 1000 cycles and good rate performance. Such favorable electrochemical performances might be ascribed to the hard carbon structure with a larger interlayer spacing and enough defects, which is significant for reversible Na+ ion intercalation and deintercalation.