Disclosed is a lithium secondary battery which is excellent in battery
characteristics such as long-term cycle characteristics, capacity and
shelf life characteristics. Also disclosed is a nonaqueous electrolyte
solution which can be used for such a lithium secondary battery.
Specifically disclosed is a nonaqueous electrolyte solution for lithium
secondary batteries obtained by dissolving an electrolyte salt in a
nonaqueous solvent which is characterized by containing 0.01-10% by
weight of a carboxylate compound represented by the general formula (I)
below and 0.01-10% by weight or 0.01-10% by volume of a vinylene
carbonate and/or 1,3-propane sultone. Also disclosed is a lithium
secondary battery using such a nonaqueous electrolyte solution. (In the
formula, R.sup.2 represents a hydrogen atom or COOR.sup.3 group, R.sup.1
and R.sup.3 respectively represent an alkyl group, a cycloalkyl group, an
alkenyl group, an alkynyl group or a phenyl group, and X represents an
alkynylene group or an alkenylene group.) ##STR00001##