Method of preparing electrode using current collector having through-pores or holes
A method of preparing an electrode for a secondary battery, including: (i) a process of preparing a current collector in which through-pores or holes are formed and an electrode slurry containing an electrode active material; (ii) a process of bringing a shielding film into close contact with one surface of the current collector to shield pores or holes on the one surface of the current collector; (iii) a process of coating the electrode slurry on the other surface of the current collector to which the shielding film is not attached, and primarily drying to prepare an interim electrode; (iv) a process of removing the shielding film from the interim electrode; and (v) a process of secondarily drying the interim electrode to prepare the electrode.
1. A method of preparing an electrode for a secondary battery, comprising:
(i) preparing a current collector in which through-pores or holes are formed;
(ii) roll pressing a shielding film to bring the shielding film into close contact with one surface of the current collector to shield the through-pores or holes on the one surface of the current collector, wherein the shielding film is parafilm;
(iii) coating an electrode slurry on the other surface of the current collector to which the shielding film is not attached, and primarily drying in a range of 30° C. to 60° C. for 5 minutes to 15 minutes to prepare an interim electrode;
(iv) removing the shielding film from the interim electrode; and
(v) secondarily drying the interim electrode in a range of 60° C. to 120° C. for more than 20 hours to prepare the electrode.
2. The method of claim 1 , wherein the current collector is a metal foamed body having a porosity of 50% to 98%, a metal fiber body having a porosity of 50% to 95%, or a metal foil having an opening ratio of 15% to 70%.
3. The method of claim 2 , wherein the porosity of the metal foamed body is from 70% to 98% or the porosity of the metal fiber body is from 70% to 95%.
4. The method of claim 2 , wherein the opening ratio of the metal foamed body is from 50% to 70%.
5. The method of claim 1 , wherein the current collector has a thickness of 10 μm to 20 μm.
6. The method of claim 1 , wherein an average diameter of the through-pores is 0.1 μm to 10 μm.
7. The method of claim 1 , wherein the diameter of the holes is 0.01 mm to 1 mm.
8. The method of claim 1 , wherein an average interval between the through-pores is 0.1 μm to 1 μm.
9. The method of claim 1 , wherein the average interval between the holes is 0.01 mm to 1 mm.
10. The method of claim 1 , wherein the electrode slurry further comprises a binder and/or a conductive material.
11. The method of claim 1 , wherein between (iv) the removing the shielding film from the interim electrode and (v) the secondarily drying the interim electrode, further comprising coating the electrode slurry on one surface of the current collector from which the shielding film is removed.
12. The method of claim 1 , wherein in (iii) the coating the electrode slurry on the other surface of the current collector to which the shielding film is not attached, the electrode slurry is in all of the through-pores or holes of the current collector.