LITHIUM SECONDARY BATTERY

A lithium secondary battery comprising a positive electrode, a negative electrode, a lithium metal layer, and an electrolyte disposed between the positive electrode and the negative electrode. The negative electrode comprises a first protective layer formed on a negative electrode current collector, a second protective layer formed on the first protective layer opposite the negative electrode current collector, and a third protective layer formed inside and on one surface of the second protective layer opposite the first protective layer, and wherein the lithium metal layer is formed between the negative electrode current collector and the first protective layer in the negative electrode when lithium ions migrate from the positive electrode after charging.