Carbon-enriched petroleum pitch derived from activated carbon for conductive agent-free supercapacitors

초록

The increasing demand for high-performance energy storage devices has accelerated the development of advanced carbon-based electrodes for supercapacitors. In this study, activated carbon electrodes derived from petroleum pitch were investigated to examine the electrochemical performance of conductive-additive-free electrode architectures prepared via CO2/steam hybrid physical activation. Before activation, the pitch underwent oxidation stabilization to enhance structural stability and prevent melting. Activation was performed at 900, 950, and 1000 degrees C to evaluate the impact of temperature on pore structure and electrochemical performance. At 1000 degrees C, the resulting activated carbon exhibited a maximum specific surface area of 2338 m2/g and mesopore ratio of 37%, thereby facilitating efficient ion transport. In symmetric two-electrode cells with an organic electrolyte, PAC-Y1000 (with conductive additives) exhibited a gravimetric capacitance of 26.0F/g and retained 94.6% of its initial capacitance after 10,000 cycles. Conversely, PAC-N1000 (without conductive additives) demonstrated comparable performance with a capacitance of 25.4F/g, retention of 94.4%, and a rate capability of 91%. By achieving high carbon purity, this CO2/steam hybrid activation method eliminates the need for conductive additives, thereby simplifying electrode fabrication and enabling the cost-effective and scalable production of high-performance supercapacitor materials with excellent rate capability and cycle stability.

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