Method of making an electrode
View Patent ↗Methods for preparing an electrode comprise: providing a mixture of carbon particles and a solvent and shearing the mixture to form a dispersion of the carbon particles in the solvent; adding non-fibrillated POLY(TETRAFLUOROETHYLENE) to the dispersion to provide a resultant mixture and shearing the resultant mixture until at least a portion of the poly(tetrafluoroethylene) has been fibrillated; processing the resultant mixture into a sheet; and attaching the sheet onto a current collector. Methods for preparing sheet for the electrode and composition for the sheet are also provided.
1. A method of forming an electrode, comprising the steps of:
(a) providing a mixture of carbon particles and water and shearing the mixture to form a dispersion of the carbon particles in the water;
(b) adding non-fibrillated POLY(TETRAFLUOROETHYLENE) to the dispersion to provide a resultant mixture comprising 2-10% by dry weight of POLY(TETRAFLUOROETHYLENE), 0-30% by dry weight of a conducting material, and 60-98% by dry weight of carbon particles, wherein a ratio by weight between the water and a total of the POLY(TETRAFLUOROETHYLENE), the conducting material and the carbon particles in the resulting mixture is in a range of 3:2 to 4:1, and shearing the resultant mixture until at least a portion of the POLY(TETRAFLUOROETHYLENE) has been fibrillated;
(c) processing the resultant mixture into a sheet; and
(d) attaching the sheet to a current collector.
2. The method of claim 1 , wherein the resultant mixture is processed into the sheet by calendering.
3. The method of claim 1 , wherein each of steps (a) and (b) is operated at room temperature.
4. The method of claim 1 , wherein each of steps (a) and (b) are collectively operated in 30 seconds to 10 minutes.
5. The method of claim 1 , wherein a rate of shearing in each of steps (a) and (b) is 400-3500 rpm.
6. The method of claim 1 , wherein the conducting material comprises a strongly acidic cation ion exchange resin.
7. The method of claim 1 , wherein the conducting material comprises a strongly basic anion ion exchange resin.
8. The method of claim 1 , wherein the conducting material comprises carbon black.
9. The method of claim 1 , wherein the conducting material comprises graphite powder.
10. The method of claim 1 , wherein the non-fibrillated POLY(TETRAFLUOROETHYLENE) is added portionwise.
11. The method of claim 1 wherein the carbon particles comprise activated carbon particles.