Method of manufacturing dry binders for electrodes and method of manufacturing dry electrodes including dry binders
Disclosed herein are a method of manufacturing dry binders for electrodes usable in a dry electrode method by using a mixture of polymer powder containing a hydroxyl group (—OH) and polytetrafluoroethylene, and a method of manufacturing dry electrodes including dry binders.
1. A method of manufacturing dry electrodes, the method comprising:
preparing a polymer powder containing a hydroxyl group (—OH);
producing a first mixture by mixing the polymer powder with polytetrafluoroethylene;
producing a second mixture by mixing an active material and a conductive material;
making a clay-like product by mixing the first mixture with the second mixture;
applying the clay-like product to a surface-treated current collector; and
rolling the clay-like product to manufacture a dry electrode,
wherein the polymer powder comprises polyethylene glycol (PEG), and
wherein in the step of producing the first mixture, mixing the polymer powder with the polytetrafluoroethylene is performed using a planetary centrifugal mixer, and
in the step of making the clay-like product, mixing is performed using a planetary centrifugal mixer.
2. The method of claim 1 ,
wherein the first mixture comprises 40 to 60% by weight of the polytetrafluoroethylene and 40 to 60% by weight of the polymer powder.
3. The method of claim 1 , wherein the producing of the second mixture is performed at 1500 to 2500 rpm for 10 to 30 minutes.
4. The method of claim 1 , wherein the conductive material comprises Super P carbon black, and
wherein the active material comprises graphite.
5. The method of claim 1 , wherein the making of the clay-like product is performed at 1500 to 2500 rpm for 1 to 10 minutes.
6. The method of claim 1 , wherein the clay-like product comprises 1 to 5% by weight of a dry binder, 92 to 98% by weight of the active material, and 1 to 3% by weight of the conductive material.
7. The method of claim 1 , wherein a surface treatment is performed by coating a surface of a current collector with carbon to a thickness in a range of 10 to 30 μm.
8. The method of claim 1 , wherein the surface-treated current collector comprises copper (Cu), nickel (Ni), titanium (Ti), tungsten (W), iron (Fe), chromium (Cr), stainless steel, or any combination thereof.
9. The method of claim 1 , wherein, in the rolling of the clay-like product, the clay-like product is roll-pressed at a temperature in a range of 10 to 30° C. at a rate of 1 to 5 cm/s.
10. The method of claim 1 , wherein the dry electrode uses no solvent.