One‐Step Preparation Pitch‐Based Porous Carbon via Carbonization and Co‐Activation for High‐Performance Supercapacitors

Hierarchical porous carbon (HPC) materials for supercapacitor (SC) application are synthesized via a one‐step carbonization and activation method, using a novel composite activating agent with synergistic activation effect from mesophase pitch (MP) as precursor. The prepared mesophase pitch‐based porous carbon (MPPC) exhibits an ultra‐high specific surface area (SSA) of 2955.0 m2 g−1, well‐controlled pore size distribution (PSD), and exceptional electrochemical performance. The specific capacitance of MPPC‐4 attains up to 338.1 F g−1 at 1 A g−1 and 250.1 F g−1 at 20 A g−1, demonstrating remarkable rate capability. Furthermore, the assembled symmetric SC achieves a high energy density of 29.83 Wh kg−1 at a power density of 999.93 W kg−1 and still maintains 6.56 Wh kg−1 at a high power density of 19.89 kW kg−1. Furthermore, the SC exhibits advantageous cyclic stability, as evidenced by its remarkable capacitance retention rate of 88.55 % even after 5000 cycles. The utilization of this novel composite activating agent in the synthesis of pitch‐derived porous carbon (PC) electrode materials is an exceptionally effective and inventive process. This study explores the synergistic activation of mesophase pitch using a novel composite activator containing potassium hydroxide and potassium carbonate. The resulting hierarchically porous carbon material exhibits an extremely high specific surface area and uniform pore distribution. The assembled supercapacitor demonstrates excellent electrochemical performance and provides a new avenue for further research.