物理化学学报 >> 2005, Vol. 21 >> Issue (08): 934-938.doi: 10.3866/PKU.WHXB20050822

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阴阳离子复合掺杂对尖晶石型正极材料的影响

唐致远; 范星河; 张娜   

  1. 天津大学化工学院,天津 300072; 河北工程学院理学院,邯郸 056038
  • 收稿日期:2004-12-13 修回日期:2005-02-21 发布日期:2005-08-15
  • 通讯作者: 唐致远 E-mail:zytang@tju.edu.cn

The Anion-cation Multiple Doping Effect of Spinel Cathode Materials on Electrochemical Speciality

TANG Zhi-yuan; LU Xing-he; ZHANG Na   

  1. School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072; 2Hebei University of Engineering, Handan 056038
  • Received:2004-12-13 Revised:2005-02-21 Published:2005-08-15
  • Contact: TANG Zhi-yuan E-mail:zytang@tju.edu.cn

摘要: 采用高温固相法合成了复合离子掺杂的尖晶石型锰酸锂Li1.02CraCobLacMn2abcFyO4-y(a,b,c=0,0.01,0.02;y=0,0.02)正极材料. XRD表征合成物均具有良好的尖晶石型结构. 充放电表明多元复合掺杂产物Li1.02Cr0.01Co0.02La0.01Mn1.96F0.02O3.98作为锂离子电池正极材料较未掺杂或仅掺杂阳离子的材料能够更好地抑制可逆容量在充放电循环中的衰减,80次循环充放电比容量(120.1~113.5 mAh•g-1)仍保持94.5%以上. 高温(55 ℃)循环性能也有较大的改善. 交流阻抗测试结果表明该材料在充放电平台附近有较小的阻抗和良好的充放电可逆性.

关键词: 锂离子电池, 尖晶石, 复合掺杂, 正极材料, 电化学性能

Abstract: Li1.02CraCobLacMn2abcFyO4-y (a,b,c=0, 0.01, 0.02; y=0, 0.02) doped with several ions (anion-cation) was prepared by solid-state reaction method. X-ray diffraction showed that all the samples had perfect spinel strucure. The results of the charge/discharge curves showed that multiple doping spinel Li1.02Cr0.01Co0.02La0.01Mn1.96F0.02O3.98 had better performance than those undoped or cation-doped materials according to the inhibition of decline of reversible capacity of spinel at 25 ℃. Besides that, the multiple doping spinel also had ideal discharge capacity. And the cycle performance(120.1~113.5 mAh•g-1) was improved so obviously that 94.5% of the initial capacity was preserved after 80 cycles. Meanwhile, the elevated temperature(55 ℃) perforance of the material was improved. With the spinel Li1.02CraCobLacMn2abcFyO4-y as working electrode, Li as counter electrode and reference electrode, electro-chemical impedance tests showed that this material possessed good charge/discharge reversible capability and had the lowest impedance on the stage of charge/discharge.

Key words: Lithium-ion batteries, Spinel, Anion-cation doping, Cathode material, Electrochemical performance