Acta Phys. -Chim. Sin. ›› 2005, Vol. 21 ›› Issue (09): 957-960.doi: 10.3866/PKU.WHXB20050903

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Dependence of Li+ Diffusion Coefficients in LiMn2O4 on Charge/Discharge Cycles

TANG Xin-cun; HUANG Bo-yun; HE Yue-hui   

  1. College of Chemistry and Chemical Engineering, Central South University; State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083
  • Received:2004-12-22 Revised:2005-01-26 Published:2005-09-15
  • Contact: TANG Xin-cun E-mail:tangxc@csu.edu.cn

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Abstract: The solid diffusion coefficient of lithium-ion in spinel LiMn2O4 cathode material has been investigated by the capacity intermittent titration technique (CITT) at different voltages and at different charge/discharge cycles. Results show that there are two minimum peaks in the curves of the solid diffusion coefficient (D) vs voltage (E) at 3.95 V and 4.12 V in the voltage range from 3.85 V to 4.30 V. The curves of lgD－E for the first 20 cycles show that the two minimum peaks are gradually flatted out and the values of solid diffusion coefficient tend to increase when the cycling number increases. The results suggest that LiMn2O4 cathode material has the ability of self-diffusion-enhance during intercalation/deintercalation of lithium-ion.

Key words: Capacity intermittent titration technique, Solid diffusion coefficient, LiMn2O4, Lithium-ion batteries