Li二次電池正極活物質LiMn_2O_4の物性, 電極特性における超音波処理の影響 [in Japanese] Effect of Supersonic-Wave Treatment on Property and Electrode Characteristics of LiMn_2O_4 as a Cathode Active Material for Li Secondary Battery [in Japanese]
Access this Article
Search this Article
In order to improve cathode property of LiMn<sub>2</sub>O<sub>4</sub>, we performed supersonic-wave treatments on LiMn<sub>2</sub>O<sub>4</sub> powder in a Zn-containing aqueous solution and then heat-treated the obtained powder. Investigations on the samples clarified that the lattice constant of LiMn<sub>2</sub>O<sub>4</sub> decreased and the Mn valence increased by the treatments, indicating a partial substitution of Zn for Mn. From charge-discharge cycle tests, it was demonstrated that the cycle performance of LiMn<sub>2</sub>O<sub>4</sub> was drastically improved by the treatments although the first discharge capacity was deteriorated. We also carried out the investigations on the cathodes and electrolytes after the cycle tests, and found that the crystal structure of LiMn<sub>2</sub>O<sub>4</sub> was stabilized by the treatments. From these results, it could be concluded that the partial substitution of Zn for Mn and/or a surface modification induced by the supersonic-wave treatments stabilized the crystal structure of LiMn<sub>2</sub>O<sub>4</sub> and thus resulted in the better cycle performance.
Electrochemistry 76(11), 808-812, 2008-11-05
The Electrochemical Society of Japan