Rechargeable electrochemical energy storage device
A rechargeable energy storage device is disclosed. In at least one embodiment the energy storage device includes an air electrode providing an electrochemical process comprising reduction and evolution of oxygen and a capacitive electrode enables an electrode process consisting of non-faradic reactions based on ion absorption/desorption and/or faradic reactions. This rechargeable energy storage device is a hybrid system of fuel cells and ultracapacitors, pseudocapacitors, and/or secondary batteries.
1. A hybrid rechargeable energy storage device comprising:
an air electrode, wherein an electrochemical process comprising reduction and evolution of oxygen takes place;
a capacitive electrode comprising a double layer electrochemical capacitor that stores energy through nonfaradic reaction;
a separator which is ion-permeable; and
an electrolyte containing ions for non-faradic and faradic reactions,
wherein said capacitive electrode comprises at least one material selected from electro-inert materials comprising activated carbons, porous carbons, carbon foams, carbon fibers, carbon nanotubes, grapheme, and carbon nanoparticles, which is structured to provide a non-faradic reaction, and
wherein a capacitive electrode process comprises a nonfaradic reaction which contributes to at least about 20% of the overall specific capacitance of the capacitive electrode.
2. The rechargeable energy storage device of claim 1 , wherein the capacitive electrode process comprises a nonfaradic reaction which contributes to at least about 50% of the overall specific capacitance of said capacitive electrode.
3. The rechargeable energy storage device of claim 1 , wherein the capacitive electrode process comprises a nonfaradic reaction which contributes to at least about 90% of the overall specific capacitance of said capacitive electrode.
4. The rechargeable energy storage device of claim 1 , wherein said air electrode is the positive electrode and said capacitive electrode is the negative electrode of said rechargeable energy storage device.
5. The rechargeable energy storage device of claim 1 , wherein said air electrode is the negative electrode and said capacitive electrode is the positive electrode of said rechargeable energy storage device.
6. The rechargeable energy storage device of claim 1 , wherein said air electrode comprises a porous gas-diffusion layer, wherein ingress and egress of oxygen is achieved through the porous gas-diffusion layer.
7. The rechargeable energy storage device of claim 1 , wherein said air electrode comprises two separated electrodes, wherein the reduction and evolution of oxygen are at individual separated electrodes.
8. The rechargeable energy storage device of claim 1 , wherein said air electrode contains one or more catalysts enabling reduction and evolution of oxygen.
9. The rechargeable energy storage device of claim 1 , wherein said air electrode comprises at least one catalyst selected from metals, pyrolyzed metal porphyrins, metal oxides, metal hydroxides, metal nitrides, and functionalized carbonaceous materials, for oxygen reduction.
10. The rechargeable energy storage device of claim 1 , wherein said air electrode comprises at least one catalyst selected from metals, metal oxides, metal sulfides, metal carbides, and metal phosphates, for oxygen evolution.
11. The rechargeable energy storage device of claim 1 , wherein said air electrode comprises at least one bi-functional catalyst selected from the group comprising metals, pyrolyzed metal porphyins, metal oxides, metal hydroxides, metal nitrides, and functionalized carbonaceous materials.
12. The rechargeable energy storage device of claim 1 , wherein said air electrode comprises an electrically conductive current collector selected from metals, conductive carbons, conductive oxides, and conductive polymers.
13. The rechargeable energy storage device of claim 1 , wherein said capacitive electrode comprises at least one material selected from electro-active materials, comprising metals that can form alloys with the metal cations from electrolyte during charging, semimetals, nonmetals, metal oxides, metal borates, metal sulfides, metal selenides, metal phosphides, metal nitrides, fluorinated carbons, metal phosphates, metal fluorides, metal sulfates, metal borates, metal vanadates, polyoxometalates, conductive polymers, and their mixtures, which provide a faradic reaction.
14. The rechargeable energy storage device of claim 1 , wherein said capacitive electrode comprises a mixture or composite of at least one electro-inert electrode material providing a non-faradic reaction and at least one electro-active electrode material providing a faradic reaction.
15. The rechargeable energy storage device of claim 1 , wherein said electrolyte comprises an aqueous solution containing acid, base, salt, or their mixtures.
16. The rechargeable energy storage device of claim 1 , wherein said electrolyte comprises a nonaqueous electrolyte selected from organic solvents, polymer gels, polymers, ionic liquids, and ion-conductive solids.
17. The rechargeable energy storage device of claim 16 , wherein said organic solvent comprises ethylene carbonate, diethyl carbonate, propylene carbonate, and acetonitrile.
18. The rechargeable energy storage device of claim 16 , wherein said ion-conductive solid comprises lithium titanium phosphate and materials occupying perovskite-, NASICON- and Li 4 SiO 4 -type crystal structures.
19. A hybrid rechargeable energy storage device comprising:
a negative air electrode comprising at least one catalyst for oxygen reduction and evolution;
a positive capacitive electrode comprising a double layer electrochemical capacitor comprising at least one capacitive material for charge storage;
an ion-permeable membrane; and
a non-aqueous electrolyte containing ions for non-faradic and faradic reactions,
wherein the positive capacitive electrode comprises at least one material selected from electro-inert materials comprising activated carbons, porous carbons, carbon foams, carbon fibers, carbon nanotubes, grapheme, and carbon nanoparticles, which is structured to provide a non-faradic reaction, and
wherein a capacitive electrode process comprises a nonfaradic reaction which contributes to least about 20% of the overall specific capacitance of the capacitive electrode.
20. The rechargeable energy storage device of claim 19 , wherein said capacitive material comprises at least one material selected from carbonaceous materials, fluorinated carbons, nonmetals, metal fluorides, metal oxides, metal phosphates, metal sulfates, metal borates, metal vanadates, and their mixtures.
21. A hybrid rechargeable energy storage device comprising:
a positive air electrode comprising at least one catalyst for oxygen reduction and evolution;
a negative capacitive electrode comprising a double layer electrochemical capacitor comprising at least an electro-active material consisting of a composite or compound;
an ion permeable separator; and
a non-aqueous electrolyte containing metal ions,
wherein the negative capacitive electrode comprises at least one material selected from electro-inert materials comprising activated carbons, porous carbons, carbon foams, carbon fibers, carbon nanotubes, graphene, and carbon nanoparticles, which is structured to provide a non-faradic reaction, and
wherein a capacitive electrode process comprises a nonfaradic reaction which contributes to at least about 20% of the overall specific capacitance of the capacitive electrode.
22. The rechargeable energy storage device of claim 21 , wherein said electro-active material comprises a composite containing a carbonaceous material and a material selected from semimetals and metals that do not dissolve during discharging.
23. The rechargeable energy storage device of claim 21 , wherein said electro-active material comprises a compound selected from metal oxides, metal sulfides, metal selenides, metal phosphides, metal borates, metal nitrides, and their mixtures.
24. The rechargeable energy storage device of claim 1 , wherein said capacitive electrode comprises a current collector and a capacitance-active material coated on the current collector.
25. The rechargeable energy storage device of claim 24 , wherein said capacitive electrode further comprises a conductive additive and a polymer binder.
26. The rechargeable energy storage device of claim 25 , wherein said conductive additive is selected from carbon black, acetylene black, ketjen black, activated carbon, carbon nanowires, carbon nanotubes, graphite, graphene, and metal particles including copper, silver, nickel, titanium, aluminum, and conducting polymers.