Carbonylated Porous Carbon from Organic Acid Salts for High-Performance Supercapacitors

Supercapacitors, particularly porous carbon-based electric double-layer capacitors (PC-EDLCs), are crucial for next-generation energy storage but face limitations in capacitance enhancement and microstructure manipulation. Conventional carbonization–activation methods suffer from energy inefficiency, poor pore structure regulation, loss of functional groups, and inability to create optimal conducting-adsorption hybrid structures. This study presents a novel, tunable one-step thermal synthesis strategy based on the self-activation reaction of potassium carboxylate precursors. A precarbonization step is induced to enrich the oxygen-containing functional groups at the porous carbon surface, followed by activation at 800 °C. While this pretreatment reduces the specific surface area, it significantly increases the specific capacitance to 279 F g–1 by introducing substantial pseudocapacitance and optimizing the conductivity of the carbon skeleton. The resulting carbonylated porous carbon exhibits outstanding supercapacitor performance, with a high capacitance retention of 93% after 10,000 cycles and an energy density of 12.8 Wh kg–1. This work offers an efficient, energy-saving, and structurally tunable pathway for preparing high-performance porous carbon materials.