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The defense date of the thesis is 2004-07-15
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URN etd-0715104-102050 Statistics This thesis had been viewed 1650 times. Download 16 times. Author Chi-Wei Yang Author's Email Address email@example.com Department Materials Engineering Year 2003 Semester 2 Degree Master Type of Document Master's Thesis Language English Page Count 107 Title The Preparation and Characterization of LiNi0.8Co0.2O2 via a Novel Co-Precipitation Keyword lithium battery cathode material cathode material lithium battery Abstract Abstract
LiNi0.8Co0.2-xAlxO2 (0 ≤ x ≤ 0.1) cathode powders were prepared with a novel co-precipitation method by heat-treating at temperatures between 700 and 900oC. The electrochemical properties as cathode material for lithium batteries were predict with XRD patterns and examine with cyclic voltammetry and capacity retention studies. Among the prepared samples, 800oC heat-treated un-substituted LiNi0.8Co0.2O2 sample shows the best cycling performance. It is the Li+ diffusion in the cathode material that causes the decreasing cycling performance by Al-substitution. That was proved with the EIS results that the apparent diffusion coefficient decreases with increasing amount of Al-substitution. The diminishing by Al-substitution may be attributed to the occupancy of Al3+ at the interstitial hexagonal 6c site that will hinder the diffusion of Li+ ion. Nevertheless, Al-substitution can improve the thermal stability effectively.
Advisor Committee She-Haung Wu - advisor
Chung Hsi Lu - co-chair
Mu-Rong Yang - co-chair
Yung-Jen Lin - co-chair
Files Date of Defense 2004-06-15 Date of Submission 2004-07-15