| 摘要 |
PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte secondary cell of good cycle characteristic having a high capacity, by forming a solvent of an electrolyte containing lithium salt so have ethylene, propylene, dimethyl and the other carbonate. SOLUTION: A positive electrode formed of lithium contained compound oxide of LiCoO2 or the like negative electrode formed by gas phase growth carbon fiber and an electrolyte containing lithium salt of LiClO4 or the like and a solvent are used, a nonaqueous electrolyte secondary cell is obtained. In this case, the solvent is formed by mixing normal chain carbonate = 40 to 60:5 to 45:5 to 45 of diethyl or ethyl methyl carbonate and the like except ethylene carbonate + propylene carbonate : dimethyl carbonate : dimethyl. The gas phase growth carbon fiber is preferably a graphitized gas phase growth carbon fiber. Further, lithium salt concentration of the electrolyte is preferably 1 to 1.6mol/l. In this way, the nonaqueous electrolyte lithium ion secondary cell, having high charge/discharge efficiency further with high capacity excellent in a cycle characteristic, is obtained. |
