NONAQUEOUS ELECTROLYTE SECONDARY CELL

In a non-aqueous electrolyte secondary battery, a cyclic carboxylic acid ester having a high conductivity in a low-temperature environment is used as an electrolyte, and, furthermore, a cyclic carbonic acid ester having at least one carbon-carbon unsaturated bond is added thereto for the inhibition of reductive decomposition of the cyclic carboxylic acid ester.