Method for manufacturing lithium secondary battery

A method for producing a lithium secondary battery, the lithium secondary battery comprising:

• a positive electrode;
• a negative electrode;
• a solid electrolyte layer interposed between the positive electrode and the negative electrode;
• and
• a functional layer interposed between the solid electrolyte layer and the negative electrode, having an electron insulating property and lithium-ion conductivity, where the functional layer is more stable than the solid electrolyte layer in reductive decomposition, wherein:
• the method comprises:
• performing a first charging step on an uncharged lithium secondary battery from uncharged state until a thickness of lithium metal deposited by the first charging step becomes 90% or more of a thickness of the functional layer, thereby forming a lithium secondary battery precursor;
• and
• performing a second charging step on the lithium secondary battery precursor, thereby forming the lithium secondary battery, wherein:
• C1<C2 is satisfied when a maximum value of a first charging rate is C1 and a minimum value of a second charging rate is C2.