氮/磷共掺杂废旧棉织物基活性炭的制备及其超级电容器性能

Preparation of a N-P co-doped waste cotton fabric-based activated carbon for supercapacitor electrodes

将废弃资源转化为能源储存材料是一种变废为宝,解决当前能源短缺、改善环境问题的新方向。本文采用熔盐一步炭化活化法,结合聚磷酸铵(APP)共掺杂技术,将废旧棉织物制备出氮/磷共掺杂的棉基活性炭材料。通过扫描电镜(SEM)、氮气吸附脱附仪(BET)、拉曼光谱仪(Raman)和X射线光电子能谱仪(XPS)对材料的形貌、结构和成分进行表征分析,同时使用循环伏安(CV)、恒流充放电(GCD)对材料的电化学性能进行测试。结果表明,将废旧棉织物与APP混合后,在ZnCl_(2)/KCl熔盐介质中经炭化活化处理得到氮/磷共掺杂活性炭,BET比表面积为751 m^(2)·g^(−1),在三电极体系中比电容高达423 F·g^(−1)(电流密度为0.25 A·g^(−1)时),在5 A·g^(−1)的大电流密度下经5000圈循环后其容量保持率高达88.9%。同时,将其组装成对称型超级电容器时,在200 W·kg^(−1)的功率密度下其能量密度为28.67 Wh·kg^(−1)。这种将废弃棉织物资源转化为储能材料的方法成功实现了废弃纺织物的高附加值再利用。

Transforming waste resources into energy storage materials is a new way to convert them into value-added products and help solve the problems of energy shortage and environmental pollution.A nitrogen-phosphorus co-doped activated carbon was synthesized from waste cotton fabric by combining carbonization and activation in ammonium polyphosphate and a molten salt sys-tem(ZnCl_(2) and KCl with a molar ratio of 52∶48).The morphology,microstructure and composition of the activated carbon were characterized by SEM,nitrogen adsorption,Raman spectroscopy and XPS.Cyclic voltammetry and galvanostatic charge/discharge were used to test the supercapacitor performance of the activated carbon.Results show that the co-doped activated carbon had a spe-cific surface area of 751 m^(2)·g^(−1),a specific capacitance of 423 F·g^(−1) at a current density of 0.25 A·g^(−1),and a capacitance retention rate of 88.9%after 5000 cycles at a current density of 5 A·g^(−1).The energy density was 28.67 Wh·kg^(−1) at a power density of 200 W·kg^(−1) for a symmetrical supercapacitor using the activated carbon.