| abstract |
A carbon-based electrode includes activated carbon, carbon black, and a binder. The binder is fluoropolymer having a molecular weight of at least 500,000 and a fluorine content of 40 to 70 wt.%. A method of forming the carbon-based electrode includes providing a binder- less conductive carbon-coated current collector, pre-treating the carbon coating with a sodium napthalenide-based solution, and depositing onto the treated carbon coating a slurry containing activated carbon, carbon black and binder. Fluoropolymer binders such PVDF are made up of carbon atoms, hydrogen atoms and fluorine atoms. A sodium napthalenide-based etchant contains metallic sodium in solution. The sodium reacts with the fluorine of the fluoropolymer, extracting it, which leaves the molecule unbalanced. During subsequent exposure to ambient conditions, hydrogen and oxygen atoms restore the equilibrium of the molecule. This results in a carbonaceous backbone rich in functional groups that are responsible for adhesion. |