| 摘要 |
PURPOSE:To improve the life of a lithium secondary battery by constituting an organic electrolyte by use of a nonaqueous solvent in which least a part of C-H bonding is preliminarily converted into C-F bonding. CONSTITUTION:Propylene carbonate is put in a reaction vessel for fluorination, N2 flow is carried out for 10 minutes to remove O2 and H2O in the system. To the vessel, 10% of F2 gas diluted with N2 is bubbled in the state where the vessel is cooled to 0 deg.C, and reacted for 75 hours with 150cc/min. LiPF6 is dissolved into the resulting fluorinated propylene carbonate to a concentration of 1 mole/l to form an electrolytic solution, and electrolytic manganese dioxide and a carbon material are used as positive electrode material and negative electrode material, respectively, to manufacture a lithium secondary battery according to the ordinary method. The deterioration of the electrolyte itself by the F radical generated from the LiPF6 used as the solute of the electrolyte can be suppressed, and the life of the battery can be improved. |
