LITHIUM SECONDARY BATTERY

The present invention relates to a lithium secondary battery manufactured to a negative electrode free battery and having lithium metal formed on a negative electrode current collector by charge, and using an electrolyte including a sacrificial salt. [0002] The lithium secondary battery forms lithium metal while being blocked from the atmosphere, and thereby fundamentally improves an existing problem caused by high reactivity of lithium metal, and, by including a sacrificial salt in an electrolyte, reduces lithium consumption caused by an irreversible reaction of a negative electrode, which may prevent decline in the battery capacity and lifetime properties.