Sodium ion-based internal hybrid electrochemical energy storage cell

An internal hybrid electrochemical cell comprising:

• a) a cathode comprising a cathode active material that contains a porphyrin compound and a carbon material, wherein said porphyrin compound is bonded to or supported by a surface of said carbon material to form a redox pair for pseudocapacitance and said carbon material is selected from activated carbon, activated carbon black, expanded graphite flakes, exfoliated graphite worms, carbon nanotube, carbon nanofiber, carbon fiber, a combination thereof, or a combination thereof with graphene;
• b) an anode comprising an anode active material selected from sodium metal, a sodium metal alloy, a sodium intercalation compound, a sodium-containing compound, or a combination thereof;
• and
• c) a sodium-containing electrolyte in physical contact with the anode and the cathode;
• wherein said cathode active material has a specific surface area no less than 100 m2/g which is in direct physical contact with said electrolyte.