Method of producing negative electrode

A method of producing a negative electrode, comprising:

• providing a negative electrode roll on which a negative electrode structure including a negative electrode current collector and a negative electrode active material layer formed on at least one surface of the negative electrode current collector is wound;
• providing a pre-lithiation bath containing a pre-lithiation solution, the pre-lithiation bath being sequentially divided into an impregnation section and a pre-lithiation section;
• impregnating the negative electrode structure with the pre-lithiation solution while unwinding the negative electrode structure from the negative electrode roll and moving the negative electrode structure through the impregnation section;
• and
• pre-lithiating the impregnated negative electrode structure by disposing the impregnated negative electrode structure in the pre-lithiation section,
• wherein the pre-lithiating the impregnated negative electrode structure includes:
• (a) disposing the impregnated negative electrode structure between two pre-lithiation structures, each pre-lithiation structure including a separator layer disposed to face the negative electrode active material layer and a lithium counter electrode layer located on the separator layer;
• (b) electrochemical charging the impregnated negative electrode structure while pressurizing the impregnated negative electrode structure at a pressure of 10 kPa to 3,500 kPa with the two pre-lithiation structures to form a pre-lithiated negative electrode structure;
• and
• (c) separating the two pre-lithiation structures from the pre-lithiated negative electrode structure and moving the pre-lithiated negative electrode structure out of the pre-lithiation section.