Synthesis and Supercapacitor Performance of Boron-Doped Phenolic Resin-Based Mesoporous Carbon

The introduction of electron-donating heteroatoms into mesoporous carbon is a strategy to significantly alter the electrochemical performance of supercapacitors. In this study, boron-doped mesoporous carbon spheres are synthesized by a high-temperature hydrothermal method, and boric acid is added during micro polymerization of phenol-formaldehyde resin microspheres to introduce boron atoms into the carbon backbone. Scanning electron microscopy (SEM) and transmission electron microscope (TEM) observations and N₂ adsorption tests verify the formation of a large number of mesopores in the porous carbon microspheres. The boron-doped mesoporous carbon has a specific surface area of 1458 m²g⁻¹. It possesses a specific capacitance in the three-electrode regime of 212.65 F g⁻¹ (at 0.5 A g⁻¹) in the three-electrode system. The supercapacitor device provided an energy density of 6.9 Wh kg⁻¹ at a power density of 149.9 W kg⁻¹. The capacitance retention after 5,000 cycles was 116.8%.