Microporous and Grain-Sized Design of High-Yield Porous Carbon Materials by Using Potassium Acetate and p-Phenylenediamine

Porouscarbon with a large specific surface area (SSA) and highporosity is the optimal electrode material for supercapacitors. However,traditional KOH activation continues to face obstacles, such as lowyield, high corrosion, and environmental contamination. In this study,nitrogen-doped (1.68% N content) porous carbon (C-PKAC(1.5)) with high yield (26.3%), large SSA (2820.65 m(2) g(-1)), and uniform size was prepared from p-phenylenediamine (PDA) using potassium acetate (KAc) instead ofpotassium hydroxide (KOH). Throughout the procedure, KAc played thefollowing crucial roles: (1) KAc and PDA could form a network of hydrogenbonds and mix homogeneously, with PDA providing a nitrogen dopantand carbon source. (2) Following polymerization, the KAc reconstitutedinto lamellae and attained geometric partition of the polymer matrix,left diffusion microtunnels, and provided a homogenized particle sizeof carbon in the subsequent stage. (3) During activation, KAc meltsand diffuses into the polymer matrix via microtunnels, where it isconverted to K2CO3 to activate from inside tooutside, thereby averting the low yield associated with conventionalactivation from outside to inside. The supercapacitor assembled forC-PKAC(1.5) has a high specific capacitance of 25.17 F g(-1), a capacitance retention rate of 82.77% after 30,000cycles, and an energy density of 8.29 W h L-1 ata power density of 199.25 W L-1.