ISSN: 1003-6326
CN: 43-1239/TG

Vol. 17    No. 8    August 2007

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Measurement of diffusion coefficient of lithium in LiFePO4 cathode material for Li-ion battery by PITT and EIS
QU Tao1, 2, TIAN Yan-wen3, ZHAI Yu-chun3
(1. School of Physics and Engineering, Sun Yat-Sen University,Guangzhou 510275, China;
2. Postdoctoral Workstation, Jiangmen JJJ Battery Co. Ltd.,Jiangmen 529000, China;
3. School of Materials and Metallurgy, Northeastern University,Shenyang 110004, China
Abstract: The chemical diffusion coefficient of Li-ion in LiFePO4 cathode material was measured by potentiostatic intermittent titration technique (PITT) and electrochemical impedance spectrum (EIS). The results show that the diffusion coefficient ranges in 10−13−10−16 cm2/s. With the change of Li content the diffusion coefficient appears an extremely large value firstly, latter appears a minimum, then increases. The calculated values by PITT are in agreement with those by EIS.
Key words: LiFePO4; diffusion coefficient; potentiostatic intermittent titration technique(PITT); electrochemical impedance spectrum(EIS)
Superintended by The China Association for Science and Technology (CAST)
Sponsored by The Nonferrous Metals Society of China (NFSOC)
Managed by Central South University (CSU)