| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a using method of a lithium ion secondary battery using an electrolyte comprising a single solvent, having high safety under high temperature, and keeping high charge/discharge performance at low temperature. <P>SOLUTION: In the using method of the lithium ion secondary battery having a negative electrode using mainly carbon as an active material, the initial charge of the negative electrode is conducted in the electrolyte containing ethylene carbonate (EC) as the solvent, and in a charge state at 0.25V or less, the solvent is replaced with propylene carbonate (PC), and discharge cutoff voltage is set at 0.25V or less and charge cutoff voltage is set at 0.0V or more for using. The electrolyte containing ethylene carbonate as the solvent may contain other solvents such as DEC as far as ethylene carbonate is contained as the solvent. <P>COPYRIGHT: (C)2004,JPO |
