Enhanced energy storage performance of activated carbon through tannic acid-ferric ion coordination

This study modified activated carbon (AC) with tannic acid (TA) and ferric ions (Fe3+) to create AC-TA-Fe composites for supercapacitor electrodes. AC-TA-Fe0.2 showed the best performance, achieving a specific capacitance of 199.7 F·g-1 at 1 A·g-1 . In a symmetric supercapacitor, it delivered 8.7 Wh·kg-1 at 2750 W·kg-1 and retained nearly 100% capacity after 10,000 cycles. The enhanced performance was due to the synergistic effects of TA and Fe, which improved surface redox activity, conductivity, and pore structure. This highlights TA and Fe-based modifications for efficient, durable electrode materials in energy storage.