混合溶剂法调控镍基MOF纳米结构及其电化学性能  

Nickel-Based MOF Nanostructures Modulated by Mixed Solution Method and Their Electrochemical Properties

作　　者：葛威 张文磊 李廷鱼 郭丽芳 李刚 Ge Wei;Zhang Wenlei;Li Tingyu;Guo Lifang;Li Gang(Center of Nano Energy and Devices,College of Information and Computer,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]太原理工大学信息与计算机学院纳米能源与器件中心,太原030024

出　　处：《微纳电子技术》2021年第9期769-775,803,共8页Micronanoelectronic Technology

基　　金：国家自然科学基金资助项目(U1810204,61901293,22002083,21905099);山西省自然科学基金资助项目(201901D111099);山西省高校科技创新研究项目(2016138)。

摘　　要：金属有机框架(MOF)具有高比表面积、结构丰富、孔道可调且含大量不饱和配位点等优点,但较差的导电性限制了其在电化学储能领域的应用。以溶剂热法的方式,通过调节N,N-二甲基甲酰胺(DMF)中溶剂成分(去离子水、乙醇)合成了四种不同形貌的Ni-MOF,实现形貌结构调控改善其导电性进而提升其电化学性能。实验结果表明:Ni-MOF形貌结构受溶剂成分影响较大进而影响其比表面积,当电流密度为1 A·g^(-1)时,在3 mol/L KOH的电解液中由DMF、去离子水和乙醇共同作为溶剂时合成的Ni-MOF纳米片状结构表现出更优异的电化学性能,比电容高达994 A·g^(-1),3000次循环充放电后依然能够保持初始比电容的80%。表明大比表面积的纳米结构能为电化学储能提供更多的反应活性位点,缩短离子和电荷的传输距离,有效提高电极材料比电容。Metal-organic frameworks(MOFs)have the advantages of high specific surface area,rich structure,tunable pore channels and a large number of unsaturated coordination sites,but poor electrical conductivity limits their applications in electrochemical energy storage.The four Ni-MOFs with different morphologies were synthesized by adjusting the solvent composition(deionized water and ethanol)in N,N-dimethylformamide(DMF)through solvothermal method to achieve morphological structure modulation to improve their electrical conductivity and then their electrochemical properties.The experimental results show that the morphological structure of Ni-MOFs is greatly affected by the solvent composition and then the specific surface area is affected.When the current density is 1 A·g^(-1),the Ni-MOF nanosheets synthesized in the electrolyte of 3 mol/L KOH with DMF,deionized water and ethanol as solvents show better electrochemical performance,and the specific capacitance is as high as 994 F·g^(-1),and 80%of the initial specific capacitance can still be maintained after 3000 cycles of charging and discharging.This indicates that the nanostructures with large specific surface area can provide more reactive sites for electrochemical energy storage,shorten the transmission distance of ions and charges,and effectively improve the specific capacitance of electrode materials.

关 键 词：超级电容器 溶剂热法 金属有机框架(MOF) 电极材料 电化学储能 

分 类 号：TB383[一般工业技术—材料科学与工程] TM53[电气工程—电器]