Lithium electrode, lithium secondary battery comprising same, battery module comprising lithium secondary battery, and preparation method of lithium electrode

1. A lithium electrode comprising:

a lithium metal layer; and

a silicon layer

wherein the silicon layer is bonded to the lithium metal layer through a reaction of a silicon-based compound with hydroxyl groups on the lithium metal layer,

wherein the silicon-based compound is one or more selected from the group consisting of:

2. The lithium electrode of claim 1 , wherein a water contact angle of the silicon layer is 100° or more and 160° or less.

3. The lithium electrode of claim 1 , wherein a thickness of the silicon layer is 1 nm or more and 1 μm or less.

4. A lithium secondary battery comprising the lithium electrode of claim 1 .

5. The lithium secondary battery of claim 4 , wherein the lithium electrode is a lithium electrode of the lithium secondary battery, the battery comprising:

a cathode;

an electrolyte provided between the lithium electrode and the cathode; and

a separator provided between the lithium electrode and the cathode,

wherein the electrolyte is an electrolyte liquid into which the lithium electrode and the cathode are immersed.

6. A battery module comprising the lithium secondary battery of claim 4 as a unit battery.

7. A lithium electrode comprising:

a lithium metal layer;

a silicon layer; and

a buffer layer provided between the lithium metal layer and the silicon layer,

wherein the buffer layer is bonded to the lithium metal layer through a reaction with hydroxyl groups on the lithium metal layer,

wherein the silicon layer is bonded to the buffer layer through a reaction of a silicon-based compound with hydroxyl groups on the buffer layer,

wherein the silicon-based compound is prepared with a compound represented by the following Chemical Formula 1:

wherein, in Chemical Formula 1,

one or more of R1 to R4 are each independently a halogen group, an amino group or an alkoxy group, and the rest are each independently a C 1 to C 10 alkyl group, a hydroxyl group, an aliphatic cyclic group having two rings or less, an aromatic cyclic group having two rings or less, or -L-(CF 2 ) n CF 3 , L is a direct bond or a C 1 to C 10 alkylene group, and n is an integer of 0 to 10.

8. The lithium electrode of claim 7 , wherein the silicon-based compound is prepared with a compound represented by at least one of the following Chemical Formulae 2 to 4:

wherein, in Chemical Formulae 2 to 4,

L is a direct bond or a C 1 to C 10 alkylene group, and n is an integer of 0 to 10.

9. The lithium electrode of claim 7 , wherein a water contact angle of the silicon layer is 100° or more and 160° or less.

10. The lithium electrode of claim 7 , wherein a thickness of the silicon layer is 1 nm or more and 1 μm or less.

11. The lithium electrode of claim 7 , wherein the buffer layer includes polydimethylsiloxane.

12. The lithium electrode of claim 7 , wherein a thickness of the buffer layer is 10 nm or more and 10 μm or less.

13. A lithium secondary battery comprising the lithium electrode of claim 7 .

14. The lithium secondary battery of claim 13 , wherein the lithium electrode is a lithium electrode of the lithium secondary battery, the battery comprising:

a cathode;

an electrolyte provided between the lithium electrode and the cathode; and

a separator provided between the lithium electrode and the cathode,

wherein the electrolyte is an electrolyte liquid into which the lithium electrode and the cathode are immersed.

15. A battery module comprising the lithium secondary battery of claim 13 as a unit battery.

16. A method for preparing a lithium electrode comprising

forming a buffer layer having hydroxyl groups on a surface of a release substrate;

forming a silicon layer including reacting a silicon-based compound with the hydroxyl groups on the buffer layer to bond the silicon layer with the buffer layer; and

removing the release substrate and laminating the result on a lithium metal layer,

wherein the buffer layer is bonded to the lithium metal layer through a reaction with hydroxyl groups on the lithium metal layer,

wherein the silicon-based compounds are prepared with a compound represented by the following Chemical Formula 1:

wherein, in Chemical Formula 1,

one or more of R1 to R4 are each independently a halogen group, an amino group or an alkoxy group, and the rest are each independently a C 1 to C 10 alkyl group, a hydroxyl group, an aliphatic cyclic group having two rings or less, an aromatic cyclic group having two rings or less, or -L-(CF 2 ) n CF 3 , L is a direct bond or a C 1 to C 10 alkylene group, and n is an integer of 0 to 10.

17. The method for preparing a lithium electrode of claim 16 , wherein the silicon-based compound having a substituent capable of reacting with a hydroxyl group is represented by at least one of the following Chemical Formulae 2 to 4:

wherein, in Chemical Formulae 2 to 4,

L is a direct bond or a C 1 to C 10 alkylene group, and n is an integer of 0 to 10.