• Joule heating technique (JHT) enables ultra-fast preparation of porous carbon with a heating rate of 1100 K/s, significantly reducing time and energy consumption compared to traditional furnace methods.
• The resulting porous carbon exhibits a high specific surface area of 1652.7 m2/g and an excellent specific capacitance of 476.0 F/g in aqueous alkaline electrolyte, with 75.1% capacitance retention at 64.0 A/g.
• Symmetric supercapacitors using this carbon achieve maximum energy densities of 33.3 Wh/kg (water-in-salt) and 50.8 Wh/kg (organic electrolyte), with high power densities and excellent cycling stability (93.1% retention after 10,000 cycles in water-in-salt).
• JHT allows precise control of pyrolysis, enabling tailored pore structures and properties, positioning it as a promising ultra-fast method for energy storage materials.