摘要
针对活性炭比电容低的问题,利用金属有机骨架(MOFs)大的比表面积和丰富孔隙结构,研究了一种协同双电层机制与赝电容特性的MOFs衍生多孔碳与活性炭的杂化复合材料.通过设计不同的Zn/Co比和碳化温度,制备了 N掺杂多孔碳复合材料.ZCPC@AC-800经三电极体系测试,以6 mol/L KOH为电解质,在0.5 A/g时,比电容为327.5 F/g,高于单金属原子生成的MOF衍生多孔碳复合材料,这是由于纳米复合材料中双金属MOF在热解过程中能提供更加多样的活性位点.此外,在电位窗口为0～1.5 V的3 mol/L KOH电解液中组装的对称超级电容器(ZCPC@AC-800//ZCPC@AC-800)在375 W/kg的功率密度下,具有21 Wh/kg的能量密度.经循环测试,5 A/g时充放电5 000次后,其初始比电容仍保持80％.
Abstract
Aiming at the problem of low specific capacitance of activated carbon,utilizing the large specific sur-face area and abundant pore structure of metal organic frameworks(MOFs),a synergistic bilayer mechanism with pseudocapacitive properties of MOFs-derived porous carbon hybrid composites with activated carbon was investigated in this paper.N-doped porous carbon composites were prepared by designing different Zn/Co ratios and carbonization temperatures.ZCPC@AC-800 was tested in a three-electrode system and showed a specific ca-pacitance of 327.5 F/g at 0.5 A/g,which was higher than that of the MOF-derived porous carbon composites generated from monometallic atoms,due to the fact that the bimetallic MOFs in the nanocomposites could pro-vide a more diverse range of active sites during pyrolysis.In addition,symmetric supercapacitors(ZCPC@AC-800//ZCPC@AC-800)assembled in a 3 mol/L KOH electrolyte with a potential window of 0-1.5 V have an en-ergy density of 21 Wh/kg at a power density of 375 W/kg.After cycling test,its initial specific capacitance re-mained 80％after 5 000 times of charging and discharging at 5 A/g.
基金项目
广西科技计划项目(桂科AD23023013)
广西科技计划项目(桂科AB23075218)
广西电子信息材料构效关系重点实验室重点基金(201002-Z)
桂林市科学研究与技术开发计划项目(20220120-1)
电子信息材料与器件教育部工程研究中心重点基金项目(EIMD-AA202001)
维普
万方数据