摘要
为了开发经济、高性能的水电解质超级电容器电极材料,以聚丙烯腈(PAN)、木质素和聚苯乙烯(PS)为前驱体,采用静电纺丝法制备了低成本的多通道碳纳米纤维原丝,进一步预氧化和炭化后制得PAN/PS/木质素碳纳米纤维(PPLCNFs),当PS添加量为0、0.5、0.75、1.0 g时,样品分别标记为PPLCNFs-0g、PPLCNFs-0.5g、PPLCNFs-0.75g、PPLCNFs-1.0g.采用扫描电镜(SEM)、透射电镜(TEM)、X射线衍射(XRD)、拉曼光谱、X射线光电子能谱(XPS)、N2吸附/脱附等温线分析了PPLCNFs材料的微观形貌、微观结构、表面化学性质和孔结构,通过三电极体系和对称式超级电容器测试了材料的电化学性能.研究结果表明:木质素的加入提高了材料的含氧官能团含量,PS的加入促进了碳纳米纤维中多条通道和多孔结构的形成,增大了材料的比表面积(SBET).在不同PS添加量的碳纳米纤维样品中,PPLCNFs-0.75g表现出最优异的结构特性和电化学性能,其纤维横截面呈莲藕状,内部通道多且直径小,SBET高达412 m2/g,孔容为0.24 cm3/g.在三电极体系中,PPLCNFs-0.75g在电流密度为0.5 A/g时,表现出276 F/g的高比电容,当电流密度增加到100 A/g时,其电容保持率为53.7%,明显优于其他样品.以PPLCNFs-0.75g为电极组装的对称式超级电容器具有良好的储能特性和循环稳定性,在电流密度为 0.5 A/g时,比电容为186 F/g,当电流密度增加到100 A/g时,其电容保持率为52.6%;在1A/g的电流密度下进行10 000 次循环后,电容保持率为99.8%,库仑效率为99.6%.
Abstract
In order to develop cost-effective and high-performance electrode materials for aqueous electrolyte supercapacitors,this study used polyacrylonitrile(PAN),lignin,and polystyrene(PS)as precursors to prepare low-cost multi-channel carbon nanofibers(CNFs)via electrospinning.The PAN/PS/lignin carbon nanofibers(PPLCNFs)were further pre-oxidized and carbonized.The samples with different addition amounts of 0 g,0.5 g,0.75 g,and 1.0 g were labeled as PPLCNFs-0g,PPLCNFs-0.5g,PPLCNFs-0.75g,and PPLCNFs-1.0g,respectively.The microstructure,surface chemical properties,and pore structure of the PPLCNFs materials were analyzed using scanning electron microscope(SEM),transmission electron microscopy(TEM),X-ray diffraction(XRD),Raman spectroscopy,X-ray photoelectron spectroscopy(XPS),and N2 adsorption/desorption isotherms.The electrochemical properties of the materials were evaluated using three-electrode system and symmetric supercapacitor testing.The results showed that the addition of lignin increased the oxygen-containing functional groups,the addition of PS promoted the formation of multiple channels and porous structures in the carbon nanofibers,increasing the specific surface area of the materials.Among the carbon nanofiber samples with different PS addition amounts,PPLCNFs-0.75g exhibited the most favorable structural characteristics and electrochemical performance.It had a lotus root-shaped cross-section,multiple internal channels with small diameters,a high specific surface area(SBET)of 412 m2/g,and a pore volume of 0.24 cm3/g.In the three-electrode system,PPLCNFs-0.75g showed a high specific capacitance of 276 F/g at a current density of 0.5 A/g.When the current density increased to 100 A/g,the specific capacitance retention rate was 53.7%,which was significantly higher than that of the other samples.The symmetric supercapacitor assembled with PPLCNFs-0.75g as the electrode exhibited good energy storage characteristics and cycling stability.At a current density of 0.5 A/g,the specific capacitance was 186 F/g.When the current density increased to 100 A/g,the capacitance retention rate was 52.6%.After 10 000 cycles at a current density of 1 A/g,the capacitance retention rate and coulombic efficiency were99.8%and99.6%,respectively.
基金项目
福建省高等学校产学研联合创新项目(2022H6002)
福建省科技创新重点项目(2022G02020)
厦泉国家自主创新示范区先进电化储能技术协同创新平台项目(3502ZCQXT2022001)
维普
万方数据