Carbonization and structural evolution of bituminous coal-derived carbons material toward supercapacitor applications
摘要
Coal-derived carbon materials have garnered significant interest for energy storage applications due to their abundance, cost-effectiveness, and straightforward processing methods. This study investigates the direct carbonization of bituminous coal at various temperatures (500, 700, and 900 °C) and analyzed the evolution of carbon structure and nitrogen functionalities. In addition, the effects on supercapacitor performance were studied. Structural transformations and nitrogen group changes were observed with increasing temperature. At 500 °C, pyrrolic-N was the predominant, and it gradually converted to pyridinic-N at 700 °C, significantly enhancing charge storage capacity. Further increasing the temperature to 900 °C transformed the pyridinic-N into Graphitic- N, improving conductivity. Electrochemical analysis revealed that the sample carbonized at 700 °C exhibited the highest specific capacitance of 73.6 F g−1, attributed to the high content of pyridinic-N, which contributes to pseudo-capacitance via redox reactions. These findings highlight the potential of coal-derived carbon via carbonization as cost-effective and efficient supercapacitor electrode materials. This work demonstrates the importance of optimizing carbonization conditions to balance aromatic carbon structure and nitrogen functionalities for enhanced electrochemical performance.
Graphical Abstract