An object of the invention is to provide such a battery that has a high
capacity, is excellent in storage characteristics, cycle characteristics
and continuous charging characteristics, and is small in gas generation
amount, whereby size reduction and improvement in performance of a
lithium secondary battery can be attained.The present invention relates
to a nonaqueous electrolytic solution comprising a lithium salt and a
nonaqueous solvent dissolving the same, wherein the electrolytic solution
contains, as the lithium salt, LiPF.sub.6 in a concentration of from 0.2
to 2 mole/L, and LiBF.sub.4 and/or a compound represented by the
following formula (1) in a molar ratio of from 0.005 to 0.4 with respect
to LiPF.sub.6, and the nonaqueous solvent mainly comprises (1) ethylene
carbonate and/or propylene carbonate, (2-1) a symmetric linear carbonate,
(2-2) an asymmetric linear carbonate, and (3) vinylene carbonate.