A method to prepare a coated current collector electrode of a flow through capacitor. The method includes preparing a coating paste includes: 10-50 weight % of carbon having a specific surface area of at least 500 m2/g; 0.3-5 weight % of a binder; 10-50 weight % based on the total paste of a first solvent having a first boiling point; and 10-50 weight % based on the total paste of a second solvent having a second boiling point. The method further includes applying the coating paste on a current collector; and allowing the second solvent in the coating paste applied on the current collector to evaporate at a temperature lower than the first boiling point.