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.