电解液添加剂NaHCO_(3)对多孔氮化铌纤维电化学性能的影响  

Effect of electrolyte additive NaHCO_(3) on electrochemical performance of porous niobium nitride fibers

作　　者：崔静轩 吕东风 张学凤 郭鑫鑫 刘洁 张澳寒 崔帅 魏恒勇 卜景龙 CUI Jing-xuan;LYU Dong-feng;ZHANG Xue-feng;GUO Xin-xin;LIU Jie;ZHANG Ao-han;CUI Shuai;WEI Heng-yong;BU Jing-long(College of Materials Science and Engineering,North China University of Science and Technology,Tangshan 063210,Hebei,China;Hebei Provincial Laboratory of Inorganic Non-metallic Materials,Tangshan 063210,Hebei,China;Tangshan Key Laboratory of Environmental Functional Materials,Tangshan 063210,Hebei,China;Institute of New Materials Industry Technology,North China University of Science and Technology,Tangshan 063210,Hebei,China)

机构地区：[1]华北理工大学材料科学与工程学院,河北唐山063210 [2]河北省无机非金属材料实验室,河北唐山063210 [3]唐山市环境功能材料重点实验室,河北唐山063210 [4]华北理工大学新材料产业技术研究院,河北唐山063210

出　　处：《材料工程》2021年第6期122-131,共10页Journal of Materials Engineering

基　　金：国家自然科学基金(51272066,51472072);华北理工大学杰出青年基金(JQ201712);华北理工大学2019年度创新创业训练项目(X2019083)。

摘　　要：超级电容器因其高效、快捷和循环稳定性好等因素成为应用广泛的新型储能装置,而电极材料是制约其发展的关键性问题。采用五氯化铌为原料,利用静电纺丝结合氨气还原氮化技术制备多孔氮化铌纤维,将其作为电极材料制备成Nb_(4)N_(5)||Nb_(4)N_(5)对称型扣式电容,并在Na_(2)SO_(4)水系电解液中加入NaHCO_(3)以提升电极材料的电化学性能。结果表明:制备的氮化铌纤维呈四方相,连续且表面呈现多孔化。多孔氮化铌电极存在双电层及赝电容储能两种机制,当添加15 mmol·dm^(-3)的NaHCO_(3)时,超级电容器比电容提高到187 F·g^(-1),其中,阻抗R_(1)和扩散阻抗W_(R)分别缩小为1.22Ω和1.47Ω,同时体系离子电导率提高,载流子浓度增大到6.58×10^(24)cm^(3),弛豫时间缩短至0.24 s。Supercapacitors have become a new type of energy storage device widely used due to their high efficiency,fast speed and good cycle stability,and electrode material is a key issue restricting their development.The porous niobium nitride fibers were prepared by electrospinning combined with reduction nitride technology using pentachloride as raw material,and Nb_(4)N_(5)||Nb_(4)N_(5) symmetrical button capacitance was prepared.In order to improve the electrochemical performance of electrode material,NaHCO_(3)was added into Na_(2)SO_(4) electrolyte.The results show that the prepared niobium nitride fiber exhibits a tetragonal phase,continuous and porous on the surface.The porous niobium nitride electrode has two mechanisms of electric double layer and pseudocapacitive energy storage.The specific capacitance of the capacitor increases to 187 F·g^(-1) with the NaHCO_(3) addition of 15 mmol·dm^(-3).The buffering effect inhibits the dissolution of niobium nitride,effectively reduces the solution resistance,the solution impedance R_(1) and the diffusion impedance W_(R) reduce to 1.22Ω and 1.47Ω respectively and the ionic conductivity improves.The carrier concentration increases to 6.58×10^(24)cm^(3),and the relaxation time of the capacitor is shortened to 0.24 s at the same time.

关 键 词：能源危机 超级电容器 氮化铌纤维 电解液 电化学 

分 类 号：O469[理学—凝聚态物理] TM911.3[理学—电子物理学]