离子液体溶解法制备超级电容碳及其电化学性能研究

文章以高纤维素废纸屑为原料, 利用无机离子液体进行选择性表面溶解处理, 得到具有润胀特性的胶状前驱体, 在不同温度条件下热解制备生物质多孔碳。800 ℃下生物质多孔碳比表面积为 $ 1276.3 \, m^{2}/g $，电化学测试结果表明，其具有较高的比电容 (271 F/g)，经过 1000 次循环，电容保持率为 90.3%。为了进一步提升超级电容器的电化学性能，在 $ 1 \, mol/L \, H_{2}SO_{4} $ 电解液中加入 $ 15 \, \text{g} \, (\text{NH}_{4})_{2}\text{Fe}(\text{SO}_{4})_{2} \cdot 6\text{H}_{2}\text{O} $，超级电容器的比电容得到显著提升，电流密度为 10 A/g 时，比电容为 439 F/g，为原电容器 (221 F/g) 的 2 倍。研究结果可为生物质多孔碳超级电容器制备提供参考。

The high cellulose waste paper was treated with selective surface dissolution (SSD) in inorganic ionic liquid, the colloidal precursor with swelling characteristics was obtained, and the pyrolysis at different temperatures was conducted to prepare biomass porous carbon. The specific surface area of the biomass porous carbon prepared at 800 ℃ was 1 276.3 m²/g. The electrochemical test results showed that it had high specific capacitance (271 F/g) and the capacitance was maintained at 90.3% after 1 000 cycles. In order to further improve the electrochemical performance of supercapacitor, 15 g $ \left(\mathrm{NH}_{4}\right)_{2}\mathrm{Fe}\left(\mathrm{SO}_{4}\right)_{2} \cdot 6\mathrm{H}_{2}\mathrm{O} $ was added into 1 mol/L $ H_{2}SO_{4} $ electrolyte, and the specific capacitance of supercapacitor was significantly improved. When the current density was 10 A/g, the specific capacitance of supercapacitor was 439 F/g, which was twice that of the original capacitor (221 F/g). The research results can provide reference for the preparation of porous carbon supercapacitors.