Acta Phys. -Chim. Sin. ›› 2005, Vol. 21 ›› Issue (08): 934-938.doi: 10.3866/PKU.WHXB20050822

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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

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