Electrochemical double-layer energy storage cells with high energy density and high power density

• US 20050014643A1
• Filed: 11/26/2001
• Published: 01/20/2005
• Est. Priority Date: 11/27/2000
• Status: Abandoned Application

• Current Assignee: CEC Bank SA
• Original Assignee: CEC Bank SA
• Inventors: Lini, Hedi, Lini, Chantal
• Application Number:
  US10/432,590
• Publication Number:
  US 20050014643A1
• Time in Patent Office: Days
• US Class Current: 502/432
• CPC Class Codes: C01B 32/336 characterised by gaseous activating agents
• CPC Class Codes: H01G 11/34 characterised by carbonisation or activation of carbon
• CPC Class Codes: H01G 11/38 Carbon pastes or blends; Binders or additives therein
• CPC Class Codes: H01G 11/44 Raw materials therefor, e.g. resins or coal
• 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: H01M 14/00 Electrochemical current or voltage generators not provided for in groups H01M6/00 - H01M12/00; Manufacture thereof
• CPC Class Codes: H01M 4/133 Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/583 Carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/622 being polymers
• CPC Class Codes: H01M 4/96 Carbon-based electrodes
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

The invention concerns a method for preparing activated carbons based on wood, preferably softwood and in particular pine wood, for making electrodes for energy storage cells, particularly for super-capacitors. Said activated carbons have a volume of mesopores less than 75% of the total pore volume and a volume of micropores less than 57% of the total pore volume. The invention also concerns a method for making an electrode for energy storage cell, comprising the application of such an activated carbon on a support, preferably by coating derived from a slurry. The energy storage cells using said activated carbons advantageously provide a better compromise between energy density and power density.

Claims

1. A process for the preparation of a porous carbonaceous material comprising the following stages:

a) carbonization of wood, preferably of softwood, and advantageously of pine wood, at a temperature of between 500 and 800°

C.;

b) thermal activation of the wood carbon obtained in a thin layer at a temperature of between 800 and 1 100°

C. in the presence of steam and/or of carbon dioxide;

the activated carbon obtained after stage b) exhibiting a volume of mesopores of less than 75% of the total pore volume and a volume of micropores of less than 75% of the total pore volume.

2. The process as claimed in claim 1, in which the activated carbon 15 obtained in stage b) exhibits a content of mesopores of between 40 and 60% of the total pore volume.

3. The process as claimed in claim 1, in which the activated carbon obtained in stage b) exhibits a content of micropores of between 20% and 20 40% of the total pore volume.

4. The process as claimed in claim 1, in which the activated carbon obtained in stage b) exhibits a pore volume of greater than 0.8 cm³/g, preferably of greater than 1 cm³/g.

5. The process as claimed in claim 1, in which the activated carbon obtained in stage b) exhibits a volume of micropores of between 0.2 and 0.6 cm³/g.

6. The process as claimed in claim 1, in which the activated carbon obtained in stage b) exhibits volume of mesopores is of between 0.4 and 0.8 cm³/g.

7. The process as claimed in claim 1, in which the activated carbon obtained after stage b) exhibits a specific surface of greater than 800 m²/g.

8. An electrode based on activated carbon comprising activated carbon capable of being obtained by the process as in claim 1.

10. The electrode as claimed in claim 8, characterized in that the electrode comprises activated carbon binder in a ratio by weight of 10/90 to 90/10, 10 preferably of 30/70 to 70/30.

11. The electrode as claimed in claim 8, characterized in that the binder is a polymer, preferably a thermoplastic and advantageously a polyether and/or polyalcohol.

12. A process for the manufacture of an electrode for an electrochemical double-layer energy storage cell comprising the stage of preparation of an activated carbon as claimed in claim 1;

application of this activated carbon to a support.

13. The manufacturing process as claimed in claim 12, in which a slip is formed beforehand from the activated carbon derived from pine wood with a binder in a suitable solvent and that the solvent is evaporated after the application to a support.

14. The process as claimed in claim 12, in which the binder is a polymer, preferably a thermoplastic polymer and advantageously a polyether and/or a polyalcohol.

15. The process as claimed in claim 12, in which the activated carbon is mixed with the binder in a ratio by weight of 90/10 to 10/90, preferably of 30/70 to 70/30.

16. The process as claimed in claim 12, in which the application 35 is carried out by coating.

17. An electrochemical double-layer energy storage cell comprising at least one electrode as claimed in claim 8.

18. The cell as claimed in claim 16, exhibiting an energy density of greater than 3 Wh/kg, preferably of greater than 4 Wh/kg, and an energy power of greater than 4 kW/kg, preferably of greater than 5 kW/kg.

9. An electrode based on activated carbon comprising activated carbon based on wood exhibiting a volume of mesopores of less than 75% of the total pore volume and a volume of micropores of less than 75% of the total pore volume.