Electrodes and electric double layer capacitance devices comprising an activated carbon cryogel

• US 8,467,170 B2
• Filed: 10/05/2010
• Issued: 06/18/2013
• Est. Priority Date: 11/15/2006
• Status: Active Grant

• Current Assignee: BASF SE
• Original Assignee: EnerG2, Inc., University of Washington
• Inventors: Feaver, Aaron M., Cao, Guozhong
• Primary Examiner(s): Sinclair, David M
• Application Number:
  US12/897,969
• Publication Number:
  US 20110199716A1
• Time in Patent Office: 987 Days
• Field of Search: 361/502
• US Class Current: 361/502
• CPC Class Codes: C01B 32/30 Active carbon
• CPC Class Codes: C01B 32/318 characterised by the starting materials
• CPC Class Codes: H01G 11/24 characterised by structural features of the materials making up or comprised in the electrodes, e.g. form, surface area or porosity; characterised by the structural features of powders or particles used therefor
• CPC Class Codes: H01G 11/26 characterised by their structure, e.g. multi-layered, porosity or surface features
• CPC Class Codes: H01G 11/30 characterised by their material
• CPC Class Codes: H01G 11/32 Carbon-based
• CPC Class Codes: H01G 11/34 characterised by carbonisation or activation of carbon
• CPC Class Codes: H01G 11/84 Processes for the manufacture of hybrid or EDL capacitors, or components thereof
• CPC Class Codes: H01G 11/86 specially adapted for electrodes carbonisation or activation of carbon for the manufacture of electrodes H01G11/34
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors
• CPC Class Codes: Y02P 20/133 Renewable energy sources, e.g. sunlight
• CPC Class Codes: Y10T 428/249978 Voids specified as micro
• CPC Class Codes: Y10T 428/24998 Composite has more than two layers

Abstract

Electrodes and electric double layer capacitance (EDLC) devices containing an activated carbon cryogel having a tunable pore structure are disclosed. The disclosed electrodes and devices find utility in any number of electrical energy storage and distribution applications.

Claims

1. An electrode comprising a binder and an activated carbon cryogel, the activated carbon cryogel comprising:

a surface area ranging from 500 m²/g to 1000 m²/g as determined by nitrogen sorption at 77 K and BET analysis;

a pore structure comprising a pore volume ranging from 0.10 cc/g to 0.42 cc/g for pores having a diameter ranging from 0.6 nm to 1.5 nm as determined from N₂ sorption derived DFT,

wherein the specific capacitance of the electrode ranges from 20 F/g to 50 F/g when the specific capacitance is measured in an electric double layer capacitor device comprising an electrolyte comprising equal volumes of propylene carbonate and dimethylcarbonate and further comprising about 1.0 M tetraethylammonium tetrafluoroborate.

2. The electrode of claim 1, wherein the pore structure comprises a pore volume ranging from 0.08 cc/g to 0.22 cc/g for pores having a diameter ranging from 1.0 nm to 1.5 nm as determined from N₂ sorption derived DFT.

3. The electrode of claim 1 wherein the electrode is a component in a supercapacitor, an ultracapacitor, an electric double layer capacitor or a pseudo capacitor.

4. The electrode of claim 1, wherein the binder is polytetrafluorethylene, perfluoroalkoxy polymer resin, fluorinated ethylene-propylene, polyethylenetetrafluoroethylene, polyvinylfluoride, polyethylenechlorotrifluoroethylene, polyvinylidene fluoride, polychlorotrifluoroethylene or trifluoroethanol.

5. The electrode of claim 1, wherein the activated carbon cryogel further comprises a pore structure comprising:

a pore volume ranging from 0.01 cc/g to 0.15 cc/g for pores having a diameter less than 0.6 nm;

a pore volume ranging from 0.30 cc/g to 0.70 cc/g for pores having a diameter ranging from 1.0 nm to 2.0 nm; and

a pore volume ranging from 0.15 cc/g to 0.70 cc/g for pores having a diameter ranging from 2.0 nm to 4.0 nm,

wherein the pore volumes are determined from N₂ sorption derived DFT.

6. The electrode of claim 1, wherein the carbon cryogel comprises micropores comprising an effective length of less than 10 nm as determined by TEM measurements.

7. The electrode of claim 1, wherein the specific power ranges from 10 W/g to 60 W/g when the specific power is measured in an electric double layer capacitor device comprising an electrolyte comprising equal volumes of propylene carbonate and dimethylcarbonate and further comprising about 1.0 M tetraethylammonium tetrafluoroborate.

8. The electrode of claim 1, wherein the specific energy ranges from 10 J/g to 60 J/g when the specific energy is measured in an electric double layer capacitor device comprising an electrolyte comprising equal volumes of propylene carbonate and dimethylcarbonate and further comprising about 1.0 M tetraethylammonium tetrafluoroborate.

9. The electrode of claim 1, wherein the activated carbon cryogel comprises mesopores having a diameter ranging from about 2.0 to about 10.0 nm as determined from N₂ sorption derived DFT.

10. The electrode of claim 1, wherein the activated carbon cryogel comprises a pore volume ranging from about 0.15 cc/g to about 0.70 cc/g for pores having a diameter between about 2.0 nm and about 4.0 nm.

11. The electrode of claim 1, wherein the activated carbon cryogel comprises a pore volume ranging from about 0.06 cc/g to about 0.50 cc/g for pores having a diameter between about 4.0 nm and about 6.0 nm.

12. The electrode of claim 1, wherein the activated carbon cryogel comprises a pore volume ranging from about 0.01 cc/g to about 0.30 cc/g for pores having a diameter between about 6.0 nm and about 8.0 nm.

13. The electrode of claim 1, wherein the activated carbon cryogel comprises a pore volume ranging from about 0.22 cc/g to about 1.5 cc/g for pores having a diameter between about 2.0 nm and about 8.0 nm.

14. An Electric Double Layer Capacitor (EDLC) device comprising:

a) a positive electrode and a negative electrode wherein each of the positive and the negative electrodes comprise an activated carbon cryogel and a binder;

b) an inert porous separator; and

c) an electrolyte;

wherein the positive electrode and the negative electrode are separated by the inert porous separator, and wherein the activated carbon cryogel comprises;

a surface area ranging from 500 m²/g to 1000 m²/g as determined by nitrogen sorption at 77 K and BET analysis;

a pore structure comprising a pore volume ranging from 0.10 cc/g to 0.42 cc/g for pores having a diameter rang from 0.6 nm to 1.5 nm as determined from N₂ sorption derived DFT

wherein the specific capacitance of each of the positive and negative electrodes independently ranges from 20 F/g to 50 F/g when the specific capacitance is measured in an electric double layer capacitor device comprising an electrolyte comprising equal volumes of propylene carbonate and dimethylcarbonate and further comprising about 1.0 M tetraethylammonium tetrafluoroborate.

15. The EDLC device of claim 14, wherein the pore structure comprises a pore volume ranging from 0.08 cc/g to 0.22 cc/g for pores having a diameter ranging from 1.0 nm to 1.5 nm as determined from N₂ sorption derived DFT.

16. The EDLC device of claim 14, wherein the activated carbon cryogel further comprises a pore structure comprising:

a pore volume ranging from 0.01 cc/g to 0.15 cc/g for pores having a diameter less than 0.6 nm;

a pore volume ranging from 0.30 cc/g to 0.70 cc/g for pores having a diameter ranging from 1.0 nm to 2.0 nm; and

a pore volume ranging from 0.15 cc/g to 0.70 cc/g for pores having a diameter ranging from 2.0 nm to 4.0 nm,

wherein the pore volumes are determined from N₂ sorption derived DFT.

17. The EDLC device of claim 14, wherein the carbon cryogel comprises micropores comprising an effective length of less than 10 nm as determined by TEM measurements.

18. The EDLC device of claim 14, wherein the specific power of each of the positive and negative electrodes independently ranges from 10 W/g to 60 W/g when the specific power is measured in an electric double layer capacitor device comprising an electrolyte comprising equal volumes of propylene carbonate and dimethylcarbonate and further comprising about 1.0 M tetraethylammonium tetrafluoroborate.

19. The EDLC device of claim 14, wherein the specific energy of each of the positive and negative electrodes independently ranges from 10 J/g to 60 J/g when the specific energy is measured in an electric double layer capacitor device comprising an electrolyte comprising equal volumes of propylene carbonate and dimethylcarbonate and further comprising about 1.0 M tetraethylammonium tetrafluoroborate.

20. The EDLC device of claim 14, wherein the electrolyte comprises equal volumes of propylene carbonate and dimethylcarbonate and further comprises about 1.0 M tetraethylammonium-tetrafluoroborate.

21. The EDLC device of claim 14, wherein the binder is polytetrafluorethylene, perfluoroalkoxy polymer resin, fluorinated ethylene-propylene, polyethylenetetrafluoroethylene, polyvinylfluoride, polyethylenechlorotrifluoroethylene, polyvinylidene fluoride, polychlorotrifluoroethylene or trifluoroethanol.

22. The EDLC device of claim 14, wherein the inert porous separator comprises polypropylene or polyethylene.

23. The EDLC device of claim 14, further comprising a first and a second current collector each comprising a non-corrosive metal.

24. The EDLC device of claim 14, wherein the activated carbon cryogel comprises mesopores having a diameter ranging from about 2.0 to about 10.0 nm as determined from N₂ sorption derived DFT.

25. The EDLC device of claim 14, wherein the activated carbon cryogel comprises a pore volume ranging from about 0.15 cc/g to about 0.70 cc/g for pores having a diameter between about 2.0 nm and about 4.0 nm.

26. The EDLC device of claim 14, wherein the activated carbon cryogel comprises a pore volume ranging from about 0.06 cc/g to about 0.50 cc/g for pores having a diameter between about 4.0 nm and about 6.0 nm.

27. The EDLC device of claim 14, wherein the activated carbon cryogel comprises a pore volume ranging from about 0.01 cc/g to about 0.30 cc/g for pores having a diameter between about 6.0 nm and about 8.0 nm.

28. The EDLC device of claim 14, wherein the activated carbon cryogel comprises a pore volume ranging from about 0.22 cc/g to about 1.5 cc/g for pores having a diameter between about 2.0 nm and about 8.0 nm.