Capacitor electrodes for lead-acid battery with surface-modified additives

Patent metadata

Field	Value
Publication number	US-9117596-B2
Application number	US-201313851853-A
Country	US
Kind code	B2
Filing date	Mar 27, 2013
Priority date	Mar 27, 2012
Publication date	Aug 25, 2015
Grant date	Aug 25, 2015

Abstract

Electrodes, which may be composite capacitor electrodes, include carbon fibers, illustratively chopped carbon fibers having an aspect ratio of from about 100-5000, have been treated with a non-ionic surfactant, specifically the polyoxyethyleneglycol octophenyl ether, Triton X-100, to increase the hydrophilicity of the fibers. The capacitive electrodes prepared with the surface-modified carbon fibers exhibit increased charge acceptance.

First claim

The invention claimed is:

1. A lead-acid battery, comprising:
a capacitor electrode, comprising:
a lead-based current collector; and
capacitor active material disposed on the current collector, wherein the capacitor active material comprises:
a carbon capacitive material,
a conductive carbon material having a lower surface area than the carbon capacitive material, and
carbon fibers treated with polyethylene glycol-based surfactant which is adsorbed onto the carbon fibers to produce surface modified carbon fibers.

2. The lead-acid battery of claim 1 , wherein the carbon capacitive material is activated carbon.

3. The lead-acid battery of claim 1 , wherein the conductive carbon material is carbon black.

4. The lead-acid battery of claim 1 , wherein the surface modified carbon fibers have an aspect ratio of between approximately 100 and approximately 5000.

5. The lead-acid battery of claim 4 , wherein the polyethylene glycol-based surfactant is a polyoxyethyleneglycol octophenyl ether.

6. The lead-acid battery of claim 1 , wherein the capacitor electrode comprises a polymer binder.

7. The lead-acid battery of claim 6 , wherein the polymer binder is selected from the group consisting of carboxymethylcellulose, polytetrafluoroethylene, and styrene-butadiene rubber.

8. The lead-acid battery of claim 7 , wherein the polymer is polytetrafluoroethylene.

9. The lead-acid battery of claim 1 , wherein the capacitor active material is negative.

10. A lead-acid battery, comprising:
at least one PbO 2 positive electrode;
at least one Pb-based negative electrode;
a capacitor electrode electronically connected in parallel to the at least one Pb-based negative electrode, wherein the capacitor electrode comprises:
a lead-based current collector,
a capacitor active material disposed on the current collector, wherein the capacitor active material comprises:
a carbon capacitive material,
a conductive carbon material having a lower surface area than the carbon capacitive material, and
carbon fibers treated with a polyethylene glycol-based surfactant which is adsorbed onto the carbon fibers to produce surface modified carbon fibers; and

an electrolyte in communication with the at least one positive electrode and the at least one negative electrode.

11. The lead-acid battery of claim 10 , wherein the surface modified carbon fibers have an aspect ratio of between approximately 100 and approximately 5000.

12. The lead-acid battery of claim 10 , wherein the polyethylene glycol-based surfactant is a polyoxyethyleneglycol octophenyl ether.

13. The lead-acid battery of claim 10 , wherein the carbon capacitive material has a surface area greater than about 2000 m 2 /g.

14. The lead-acid battery of claim 10 , wherein the carbon capacitive material has a surface area greater than about 3000 m 2 /g.

15. The lead-acid battery of claim 10 , wherein the carbon capacitive material comprises between 10 wt % and 20 wt % of the capacitor active material.

16. The lead-acid battery of claim 10 , wherein the conductive carbon material has a surface area of approximately 100 m 2 /g or less.

17. The lead-acid battery of claim 10 , wherein the conductive carbon material comprises between 3 wt % and 5 wt % of the capacitor active material.

18. The lead-acid battery of claim 10 , wherein the surface modified carbon fibers comprise between 5 wt % and 15 wt % of the capacitor active material.

19. The lead-acid battery of claim 10 , wherein the capacitor electrode comprises an aqueous solvent.

20. The lead-acid battery of claim 1 , comprising at least one Pb-based negative electrode, wherein the at least one Pb-based negative electrode is electrically connected in parallel to the capacitor electrode.

21. The lead-acid battery of claim 20 , comprising:
at least one PbO 2 positive electrode, and
an electrolyte in communication with the at least one positive electrode and the at least one negative electrode.

Assignees

• Johnson Controls Tech Co

Inventors

• Loganathan Kavi G
• Jiang Junwei
• Wyatt Perry M
• Bose Deepan Chakkaravarthi
• Gerner Scott D

Classifications

• H01G11/04 Primary

  Hybrid capacitors · CPC title

• H01G11/40 Primary

  Fibres · CPC title

• H01G11/38

  Carbon pastes or blends; Binders or additives therein · CPC title

• H01G11/68

  characterised by their material · CPC title

• H01G11/36

  Nanostructures, e.g. nanofibres, nanotubes or fullerenes · CPC title