摘要
采用改进的溶胶凝胶燃烧法成功合成了Y^(3+)掺杂的多孔Na_(3)V_(2)(PO_(4))_(3)/C(记为NVP/C)复合材料,运用XRD、BET、SEM、HRTEM和电化学测试等手段对其进行结构表征和储钠性能测试。结果表明,半径较大的Y^(3+)取代NVP晶体结构中的部分V^(3+)导致晶格膨胀,扩大了Na^(+)的传输通道,加快了Na^(+)的迁移。在制备改性样品过程中,Y^(3+)与PO_(4)^(3-)发生反应,生成新的导电相YPO_(4),提高了复合材料的电子电导率。此外,Y^(3+)掺杂使得不规则多边形NVP颗粒球化并且尺寸略有减小。得益于适当的Y^(3+)掺杂量以及均匀的无定形碳包覆层和多孔结构,NVP/C-Y0.10样品具有优异的储钠性能,其在5 C高倍率下的首次放电比容量高达96.3 m A·h/g,经1000次循环后仍能保持82.2 m A·h/g的可逆容量。
Y^(3+)doped porous Na_(3)V_(2)(PO_(4))_(3)/C(written as NVP/C)composites were successfully synthesized by a modified sol-gel combustion method.The structure and sodium storage performance of the composites were characterized by XRD,BET,SEM,HRTEM and electrochemical tests.The results show that Y^(3+)with larger radius replaces part of V^(3+)in NVP crystal structure,which leads to lattice expansion,expands the transport channel of Na^(+)and accelerates the migration of Na^(+).In the process of preparing the modified samples,Y^(3+)reacts with PO_(4)^(3-)to form a new conductive phase YPO_(4),which improves the electronic conductivity of the composites.In addition,Y^(3+)doping results in spheroidization of irregular polygonal NVP particles and a slight reduction in their size.Benefiting from the appropriate Y^(3+)doping amount,uniform amorphous carbon coating layer and porous structure,the NVP/C-Y0.10 sample has excellent sodium storage performance with a high initial discharge specific capacity of 96.3 mA·h/g at a high rate of 5 C and a reversible capacity of 82.2 mA·h/g after 1000 cycles.
作者
李娜丽
王斌斌
LI Na-li;WANG Bin-bin(College of Vanadium and Titanium,Panzhihua University,Panzhihua 617000,China;Vanadium and Titanium Resource Comprehensive Utilization Key Laboratory of Sichuan Province,Panzhihua 617000,China)
出处
《稀有金属与硬质合金》
CAS
CSCD
北大核心
2024年第6期105-113,共9页
Rare Metals and Cemented Carbides
基金
四川省钒钛材料工程技术研究中心开放项目(2024FTGC05)
攀枝花学院校级培育类科研项目(2023PY04)
省级大学生创新创业训练计划项目(S202411360021)。
