Nitrogen-doped layered porous carbon has been successfully fabricated from the biomass of porcine bladders via carbonization and KOH activation. The effects of KOH dosage on the structure, composition and capacitive property of carbon were investigated by a variety of means (SEM, HRTEM, XRD, Raman, XPS, BET and electrochemical test). Owing to the unique layered structure and rich heteroatom content of porcine bladders, the sample obtained at a KOH/carbon mass ratio of 2 were endowed with appropriate pore structure, large specific surface area (1881.7 m² g⁻¹) and high nitrogen content (5.38%). Meanwhile, the sample exhibits the best electrochemical performance in 6 M KOH electrolyte, including high specific capacitance (322.5 F g⁻¹ at a current density of 0.5 A g⁻¹), desirable rate capability (79% capacitance retention when current density increases from 0.5 to 10 A g⁻¹) and superior cycling stability (96% capacitance retention after 5000 cycles). Furthermore, the symmetric supercapacitor assembled with this carbon electrode can deliver 10.9 Wh kg⁻¹ energy density at 0.15 kW kg⁻¹ power density, and maintain 95% capacitance after 5000 cycles. The prominent performance of this material suggests its promising application in supercapacitor electrode.

通过碳化和KOH活化，成功地从猪膀胱的生物质中制备了氮掺杂的层状多孔碳。通过多种方法（SEM，HRTEM，XRD，拉曼，XPS，BET和电化学测试）研究了KOH用量对碳的结构，组成和电容性能的影响。由于猪膀胱独特的层状结构和丰富的杂原子含量，在KOH /碳质量比为2的情况下获得的样品具有适当的孔结构，大比表面积（1881.7 m ² g ^-1）和高氮含量（ 5.38％）。同时，样品在6 M KOH电解质中表现出最佳的电化学性能，包括高比电容（322.5 F g ^-1在电流密度为0.5 A g ^-1时），理想的速率能力（电流密度从0.5 A g ^-1增加到10 A g ^-1时，电容保持率为79％）和出色的循环稳定性（5000次循环后电容保持率为96％）。此外，组装有该碳电极的对称超级电容器在0.15kW kg ^-1的功率密度下可以提供10.9 Wh kg ^-1的能量密度，并且在5000次循环之后保持95％的电容。这种材料的杰出性能表明其在超级电容器电极中的应用前景广阔。