Negative electrode for lithium secondary battery, method of manufacturing the same and lithium secondary battery using the same
The present invention relates to a negative electrode for a lithium secondary battery that can ensure a high energy density, a long-life characteristic, and stability by forming a film on a negative electrode for a lithium secondary battery and thus suppressing dendrites during electrodeposition, a method of manufacturing the same, and a lithium secondary battery using the same. The method of manufacturing the negative electrode for a lithium secondary battery according to the present invention includes preparing a sulfur dioxide-based sodium molten salt and forming a protective layer on the surface of a current collector by immersing the current collector in the sulfur dioxide-based sodium molten salt.
1. A method of manufacturing a negative electrode for a lithium secondary battery, the method comprising:
preparing a sulfur dioxide-based sodium molten salt; and
forming a protective layer on the surface of a current collector by immersing the current collector in the sulfur dioxide-based sodium molten salt.
2. The method according to claim 1 , wherein, in the formation of a protective layer, the current collector includes a lithium metal.
3. The method according to claim 1 , wherein, in the preparation of a sulfur dioxide-based sodium molten salt, the sulfur dioxide-based sodium molten salt includes NaAlCl 4 -xSO 2 (1.5≤x≤3.0) or NaGaCl 4 -xSO 2 (1.5≤x≤3.0).
4. The method according to claim 3 , wherein the preparation of a sulfur dioxide-based sodium molten salt comprises:
preparing a solid salt by mixing NaCl and AlCl 3 or GaCl 3 ; and
preparing a liquid-phase sulfur dioxide-based sodium molten salt by providing SO 2 to the solid salt.
5. The method according to claim 4 , wherein, in the formation of a protective layer, the protective layer is formed on the surface of the lithium metal and is a film including Na, Cl, or S.
6. A negative electrode for a lithium secondary battery, comprising:
a current collector; and
a protective layer formed on the surface of the current collector by immersing the current collector in a sulfur dioxide-based sodium molten salt.
7. The negative electrode for a lithium secondary battery according to claim 6 , wherein the current collector includes a lithium metal.
8. The negative electrode for a lithium secondary battery according to claim 6 , wherein the sulfur dioxide-based sodium molten salt includes NaAlCl 4 -xSO 2 (1.5≤x≤3.0) or NaGaCl 4 -xSO 2 (1.5≤x≤3.0).
9. The negative electrode for a lithium secondary battery according to claim 8 , wherein the sulfur dioxide-based sodium molten salt is formed by mixing NaCl and AlCl 3 or GaCl 3 to form a solid salt and then providing SO 2 to the solid salt.
10. The negative electrode for a lithium secondary battery according to claim 9 , wherein the protective layer is formed on the surface of the lithium metal and is a film including Na, Cl, or S.
11. A lithium secondary battery comprising a negative electrode for a lithium secondary battery including a current collector and a protective layer formed on the surface of the current collector by immersing the current collector in a sulfur dioxide-based sodium molten salt.