METHOD FOR PRE-LITHIATION/PRE-SODIATION OF NEGATIVE ELECTRODE, PRE-LITHIATED/PRE-SODIATED NEGATIVE ELECTRODE, AND LITHIUM SECONDARY BATTERY COMPRISING SAME

Disclosed is a method for pre-lithiation and pre-sodiation of a negative electrode, including the steps of: interposing a separator between a lithium ion-supplying metal sheet and a negative electrode to prepare a first simple cell; dipping the first simple cell in an electrolyte for pre-lithiation; carrying out primary electrochemical charging of the first simple cell dipped in the electrolyte for pre-lithiation to carry out pre-lithiation of the negative electrode; interposing a separator between a sodium ion-supplying metal sheet and the pre-lithiated negative electrodeto prepare a second simple cell; dipping the second simple cell in an electrolyte for pre-sodiation; and carrying out secondary electrochemical charging of the second simple cell dipped in the electrolyte for pre-sodiation to carry out pre-sodiation of the negative electrode. A pre-lithiated and pre-sodiated negative electrode obtained by the method and a lithium secondary battery including the same are also disclosed.