生物模板法合成钠离子电池Na_(2)Ti_(3)O_(7)/C负极材料及其储钠性能  

Preparation of Na_(2)Ti_(3)O_(7)/C Anode Materials for Sodium Ion Battery by Biological Template Method and Its Sodium Storage Characteristics

作　　者：华丽[1] 曾建华[1] 朱玉涵 翁方青 HUA Li;ZENG Jianhua;ZHU Yuhan;WENG Fangqing(Hubei Key Laboratory of Purification and Application of Anticancer Active Substances,School of Chemistry and Life Science,Hubei University of Education,Wuhan 430205,China)

机构地区：[1]湖北第二师范学院化学与生命科学学院,湖北省抗癌活性物质提纯与应用重点实验室,武汉430205

出　　处：《硅酸盐学报》2024年第1期46-55,共10页Journal of The Chinese Ceramic Society

基　　金：湖北省自然科学基金项目(2021CFB251);国家自然科学基金青年项目(22004029);湖北第二师范学院校级教学研究和科学研究项目(X2019013,X2020001和20XGZX10)。

摘　　要：以天然螺旋藻为生物模板合成钠离子电池Na_(2)Ti_(3)O_(7)/C负极材料,并与水热法合成Na_(2)Ti_(3)O_(7)纳米材料进行对比。结果表明:该法制备的Na_(2)Ti_(3)O_(7)/C负极材料呈良好的网络条状结构,其上有少量碳残留,首次充放电比容量分别是109.3 m A·h/g和117.6 m A·h/g。而水热法制备的Na_(2)Ti_(3)O_(7)材料首次充放电比容量分别为89.3 m A·h/g和86.3 m Ah/g。250次循环后其充放电比容量平均保持率在70%左右,明显优于水热法制备的Na_(2)Ti_(3)O_(7)负极材料(平均为35%),且有更好的循环稳定性和更高的Coulomb效率。通过对合成的Na_(2)Ti_(3)O_(7)/C和Na_(2)Ti_(3)O_(7)在不同倍率下进行20次循环后分析其放电比容量,结果表明:两者在小电流条件下放电衰减比较快,大电流放电时电化学性能相对较稳定,且在相同倍率下Na_(2)Ti_(3)O_(7)/C电极材料的稳定性较之水热法合成的Na_(2)Ti_(3)O_(7)材料好,这为大功率混合动力电车提供了较好的动力支撑。交流阻抗对比分析显示:模板法获得的Na_(2)Ti_(3)O_(7)/C在充放电过程中其电极和电解液总阻抗、电极接触电阻、钠离子电荷转移电阻、Na+在电解液中半无限扩散Wurburg阻抗均比水热法制备的Na_(2)Ti_(3)O_(7)材料要小,进一步表明以天然螺旋藻为模板合成的纳米网络条状结构可以有效提高电极材料的电化学性能且锻烧中残留碳可提高其导电性,这为新型钠电池开发和应用的提供基础支持。Introduction Sodium batteries become a novel energy storage device due to their higher safety factor and superior comprehensive performance.The existing electrode materials such as Na_(x)CoO _(2),Na_(x)TiO_(2),NaTi_(2)(PO_(4))_(3),etc.are investigated for sodium batteries.However,these electrodes have a disadvantage of poor ion/electronic conductivity,restricting their widespread application.Na_(2)Ti_(3)O_(7)is an ideal alternative titanium-based negative electrode material for sodium batteries due to its Ti^(3+)/Ti^(4+)variability and suitable redox pairs,as well as its low voltage plateau.Embedding carbon in Na_(2)Ti_(3)O_(7 )electrode for sodium ion batteries can improve their conductivity and electrochemical performance,especially for the large-scale energy storage applications with different energy density and volume requirements.In this paper,Na_(2)Ti_(3)O_(7)/C composite anode material for sodium ion battery was prepared by a special template method,and its electrochemical characteristics were investigated.Methods Na_(2)Ti_(3)O_(7)/C composite anode material for sodium ion battery was synthesized with natural spirulina as a biological template.Spirulina was added into Na_(2)Ti_(3)O_(7) precursor solution,heated and stirred in a magnetic stirrer for 1 h,and then put them in a hydrothermal reactor (with a polytetrafluoroethylene inner tank capacity of 100 mL) at 180℃for 18 h.In addition,Na_(2)Ti_(3)O_(7)precursor solution was also placed into a tank to hydrothermal reaction under the same condition for comparing with the template method.The final products were calcined in an air furnace (with a heating rate of 1℃/min from room temperature to 850℃) at850℃for 5 h to form the perfect crystals and remove the spirulina templates.A CR2032-typed buckle battery was assembled in a glove box (GRS-1200,Wuhan Grace New Energy Co.,Ltd.,China) filled in argon gas and with the synthesized Na_(2)Ti_(3)O_(7)/C or Na_(2)Ti_(3)O_(7) electrodes as anodes,high purity sodium tablets as counter electrodes.The microstructur

关 键 词：天然螺旋藻 生物模板法 水热法 三钛酸钠/碳复合材料 储钠性能 

分 类 号：O614[理学—无机化学]