稀土离子(RE=La^(3+),Gd^(3+),Lu^(3+))掺杂Na_(3)V_(2)(PO_(4))_(3)/C正极材料的制备及电化学性能研究  

Preparation and Electrochemical Properties of Rare-Earth Ion(RE=La^(3+), Gd^(3+), Lu^(3+)) Doping Na_(3)V_(2)(PO_(4))_(3)/C Cathode Materials

作　　者：焦韩 曹轶 韩华玮 郭世宏 龙震 Jiao Han;Cao Yi;Han Huawei;Guo Shihong;Long Zhen(Institute of Functional Crystals,Tianjin University of Technology,Tianjin 300384,China;School of Chemistry and Chemical Engineering,Tianjin University of Technology,Tianjin 300384,China)

机构地区：[1]天津理工大学功能晶体研究院,天津300384 [2]天津理工大学化学化工学院,天津300384

出　　处：《中国稀土学报》2024年第4期719-729,I0003,共12页Journal of the Chinese Society of Rare Earths

基　　金：国家自然科学基金项目(61835014,51890865)资助。

摘　　要：在钠离子电池正极材料体系中,钠超离子导体型Na_(3)V_(2)(PO_(4))_(3)(NVP)因其高电压平台和良好的循环稳定性而备受关注,然而,其本征电导率较差严重限制了其实际应用。通过球磨辅助固相法制备了稀土离子(La^(3+),Gd^(3+),Lu^(3+))掺杂的Na_(3)V_(2-x)RE_(x)(PO_(4))_(3)/C (x=0,0.01,0.03,0.05)正极材料。通过X射线衍射(XRD)、扫描电镜(SEM)、X射线能谱(EDS)证实了稀土离子(La^(3+),Gd^(3+),Lu^(3+))在NVP/C结构中的成功掺杂,同时通过电化学测试研究了稀土离子(La^(3+),Gd^(3+),Lu^(3+))掺杂对NVP/C的电化学性能的影响。结果表明,La^(3+)和Gd^(3+)的掺杂均能在不同程度上改善NVP/C材料的电化学性能。NVP/C-La0.03和NVP/C-Gd0.03在1C倍率下的初始放电比容量分别为110和105.5 m Ah·g^(-1),200次循环后容量保持率分别为97.5%和95.7%。在这些掺杂样品中NVP/C-La0.03表现出的电化学性能最佳,即使在5C的倍率下循环500次后,放电比容量仍可达100.05 m Ah·g^(-1)。因此,适当的稀土离子掺杂对提高NVP/C正极材料的电化学性能有一定的提升作用,为钠离子电池正极材料的深入探索提供了基础研究支撑。Na_(3)V_(2)(PO_(4))_(3)(NVP) has attracted much attention due to its high capacity and high voltage platform.However,its further development is severely limited by its poor intrinsic electron and ionic conductivity.Herein,the conductivity of NVP is improved by doping rare earth ions (La^(3+),Gd^(3+),Lu^(3+)) using a solid-state reaction method assisted by ball walling.The successful rare earth ions (La^(3+),Gd^(3+),Lu^(3+)) doping in NVP/C structure was confirmed by X-ray diffraction (XRD),scanning electron microscopy (SEM) and X-ray energy spectrum(EDS).The influence of rare earth ions (La^(3+),Gd^(3+),Lu^(3+)) doping on the electrochemical performance of NVP/C was studied by electrochemical tests.The results show that La^(3+)and Gd^(3+)doping can effectively improve the elec‐trochemical performance of NVP/C.NVP/C-La0.03 and NVP/C-Gd0.03 present an initial discharge capacity of110 and 105.5 m Ah·g^(-1) at 1C with the capacity retention rates of 97.5%and 95.7%after 200 cycles.Among the Na_(3)V_(2-x)RE_(x)(PO_(4))_(3)/C samples,NVP/C-La0.03 has the best electrochemical performance,a high discharge capacity of 100.05 m Ah·g^(-1) at 5C after 500 cycles.Therefore,proper rare earth ions doping can improve the electrochemical performance of NVP/C materials to a certain extent,which provides basic research support for further exploration of cathode materials for sodium-ion batteries.

关 键 词：钠离子电池 磷酸钒钠 正极材料 稀土离子掺杂 

分 类 号：TM911[电气工程—电力电子与电力传动]