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

Abstract 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 m 2 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.