Electrode with porous binder coating layer, method for manufacturing the same, and lithium secondary battery comprising the same
View Patent ↗An electrode with a porous binder coating layer may be manufactured in a method including (S 10 ) a step of preparing the electrode including an active material layer formed on at least one surface of a current collector; (S 20 ) a step of acquiring a binder emulsion by adding a binder to a dispersion medium; and (S 30 ) a step of coating the binder emulsion acquired at the step (S 20 ) on a surface of the active material layer of the electrode in a screen printing method using a mesh to form a binder coating layer of a porous structure.
1. A method for manufacturing an electrode with a porous binder coating layer, the method comprising:
coating a binder emulsion through a mesh surface of a mesh and onto a surface of an active material layer of an electrode to form a porous binder coating layer having a mesh pattern, wherein the binder emulsion comprises a binder and a dispersion medium, and wherein the electrode comprises the active material layer and a current collector, the active material layer disposed on at least one surface of the current collector,
wherein the mesh is applied in the form of a roll, and
wherein coating the binder emulsion through the mesh further comprises:
rotating the mesh roll;
winding the electrode in a reverse direction thereof while rotating the mesh roll such that the mesh surface and active material layer face each other; and
injecting the binder emulsion through the mesh surface and onto the surface of the active material layer during the rotation of the mesh roll and the winding of the electrode to form the porous binder coating layer having the mesh pattern.
2. The method of claim 1 , wherein the porous binder coating layer is dried during the rotation of the mesh roll and the winding of the electrode.
3. The method of claim 2 , wherein the drying is performed at 25 to 300° C.
4. The method of claim 2 , wherein the drying is performed using an air flow, and an amount of water vapor forming the air flow is 1 to 589 g/m 3 .
5. The method of claim 1 , wherein the porous binder coating layer is formed in a thickness of 0.5 to 5 μm.
6. The method of claim 1 , wherein, in the binder emulsion, the binder and the dispersion medium are provided in a weight ratio of 1:99 to 99:1.
7. The method of claim 1 , wherein the binder is a polyvinylidene fluoride (PVdF)-based polymer.
8. The method of claim 7 , wherein the PVdF-based polymer is selected from a group consisting of polyvinylidene fluoride-co-hexafluoropropylene, polyvinylidene fluoride-co-trichloroethylene, polyvinylidene fluoride-co-tetrafluoroethylene, polyvinylidene fluoride-co-trifluoroethylene, polyvinylidene fluoride-co-trifluorochloroethylene, polyvinylidene fluoride-co-ethylene, and a mixture of two or more thereof.
9. The method of claim 1 , wherein the dispersion medium is acetone, tetrahydrofuran, methylenechloride, chloroform, dimethylformamide, N-methyl-2-pyrrolidone (NMP), cyclohexane, water or a combination thereof.