LITHIUM SECONDARY BATTERY

摘要

A lithium secondary battery that exhibits a high open-circuit voltage between battery contacts at the completion of electric charge, being capable of suppressing the rate of gas generation during continuous electric charge, and that excels in cycle characteristics. For providing such a lithium secondary battery, in the electrolyte, there is incorporated a vinyl ethylene carbonate derivative together with a vinylene carbonate derivative; or incorporated 0.01 to 5 wt.% of any of lactones having a substituent at its a-position; or incorporated 0.01 to 5 wt.% of any of lactones having a carbon to carbon unsaturated bond; or incorporated a sulfonate compound of the formula: wherein L is a bivalent linkage group composed of carbon and hydrogen atoms, and R³⁰s each independently are unsubstituted or fluorine-substituted aliphatic saturated hydrocarbon groups.