Activated petroleum coke with enhanced pore accessibility for high-performance supercapacitors

The electrochemical performance and durability of activated petroleum coke (APC) and Black Pearl (BP) carbon electrodes were systematically investigated as candidate materials for supercapacitor applications. Galvanostatic charge/discharge measurements demonstrated symmetric triangular profiles for both materials, while BP exhibited a higher surface area, the APC electrode delivered higher capacitance and energy density due to its engineered pore structure. The APC electrode also showed superior rate capability and energy retention across increasing current densities, maintaining efficient charge–discharge behavior under fast cycling. Accelerated stress testing (10,000 cycles at 10 A g −1 ) further highlighted APC's durability, with minimal changes in capacitance and impedance, while BP suffered significant performance degradation, including reduced capacitance and increased resistive losses. Overall, APC emerges as a versatile and robust electrode material, well-suited for high-power supercapacitor systems requiring long-term stability. These findings highlight the importance of pore architecture, accessible surface area, and interfacial stability in the rational design of next-generation carbon-based supercapacitors.