One-Pot Ultrafast Molten-Salt Synthesis of Anthracite-Based Porous Carbon for High-Performance Capacitive Energy Storage

Porous carbon materials are promising for electrodes of supercapacitors due to their large surface area and porous channels, which provide ample charge storage sites and facilitate ion transport. In this study, we report a one-pot ultrafast molten-salt method for synthesizing porous carbon from anthracite, using a Joule heating technique at 900 °C for 3 s. The rapid heating (1150 K s–1) with KCl/K2CO3 salts results in a homogeneous medium that exfoliates and activates anthracite, yielding porous carbon with a high specific surface area of 1338 m2 g–1. It exhibits a specific capacitance of 284.6 F g–1 in KOH electrolyte, surpassing the traditional molten-salt method. The symmetrical supercapacitor assembled with TEBAF4/AN electrolyte has a specific energy of 43.9 Wh kg–1 at 375 W kg–1 and retains 90.1% of its capacity after 10,000 cycles. This study highlights the superiorities of this green, efficient, and ultrafast synthesis for developing high-performance energy storage materials.