Patent ID: 10566668

Abstract:
Provided is an internal hybrid electrochemical cell comprising: (a) a pseudocapacitance-like cathode comprising a cathode active material that contains both graphene sheets and a porphyrin compound, including porphyrin or a porphyrin complex, wherein the porphyrin compound is bonded to or supported by primary surfaces of graphene sheets to form a redox pair for pseudocapacitance; (b) a battery-like 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 the cathode active material has a specific surface area no less than 100 m2/g which is in direct physical contact with the electrolyte.