Rolled supercapacitor electrode having highly oriented flakes of exfoliated or expanded graphite and production process

Patent metadata

Field	Value
Publication number	US-10446333-B2
Application number	US-201715671611-A
Country	US
Kind code	B2
Filing date	Aug 8, 2017
Priority date	Aug 8, 2017
Publication date	Oct 15, 2019
Grant date	Oct 15, 2019

Abstract

Provided is rolled supercapacitor comprising an anode, a cathode, a porous separator, and an electrolyte, wherein the anode contains a wound anode roll of an anode active material having an anode roll length, width, and thickness and the anode active material contains flakes of graphite worms or expanded graphite that are oriented substantially parallel to the plane defined by the anode roll length and width; and/or the cathode contains a wound cathode roll of a cathode active material having a cathode roll length, width, and thickness, wherein the cathode active material contains flakes of graphite worms or expanded graphite that are oriented substantially parallel to the plane defined by the cathode roll length and width; and wherein the anode roll width and/or the cathode roll width is substantially perpendicular to the separator.

First claim

We claim:

1. A rolled supercapacitor comprising an anode, a cathode, a porous separator electronically separating said anode and said cathode, and an electrolyte in ionic contact with said anode and said cathode, wherein said anode contains a wound anode roll of an anode active material having an anode roll length, an anode roll width, and an anode roll thickness, wherein said anode active material contains flakes of exfoliated graphite worms or expanded graphite and wherein these flakes are oriented substantially parallel to a plane defined by said anode roll length and said anode roll width; and/or said cathode contains a wound cathode roll of a cathode active material having a cathode roll length, a cathode roll width, and a cathode roll thickness, wherein said cathode active material contains flakes of exfoliated graphite worms or expanded graphite that are oriented substantially parallel to a plane defined by said cathode roll length and said cathode roll width; and wherein said anode roll width and/or said cathode roll width is substantially perpendicular to said separator.

2. The rolled supercapacitor of claim 1 , wherein said flakes contain activated flakes of exfoliated graphite worms or expanded graphite having a specific surface area from 500 to 3,300 m 2 /g.

3. The rolled supercapacitor of claim 1 , wherein said flakes are attached to or coupled with a nanoscaled coating or particles of a redox pair partner selected from an intrinsically conductive polymer, a transition metal oxide, and/or an organic molecule, wherein said redox pair partner and said graphene sheets form a redox pair for pseudo-capacitance.

4. The rolled supercapacitor of claim 3 , wherein said intrinsically conducting polymer is selected from polyaniline, polypyrrole, polythiophene, polyfuran, sulfonated polyaniline, sulfonated polypyrrole, sulfonated polythiophene, sulfonated polyfuran, sulfonated polyacetylene, or a combination thereof.

5. The rolled supercapacitor of claim 2 , wherein said activated flakes are attached to or coupled with a nanoscaled coating or particles of a redox pair partner selected from an intrinsically conductive polymer, a transition metal oxide, and/or an organic molecule, wherein said redox pair partner and said graphene sheets form a redox pair for pseudo-capacitance.

6. The rolled supercapacitor of claim 5 , wherein said intrinsically conducting polymer is selected from polyaniline, polypyrrole, polythiophene, polyfuran, sulfonated polyaniline, sulfonated polypyrrole, sulfonated polythiophene, sulfonated polyfuran, sulfonated polyacetylene, or a combination thereof.

7. The rolled supercapacitor of claim 1 , further containing an anode tab connected to or integral with said anode and a cathode tab connected to or integral with said cathode.

8. The rolled supercapacitor of claim 1 , further comprising a casing that encloses said anode, said cathode, said separator, and said electrolyte therein to form a sealed supercapacitor.

9. The rolled supercapacitor of claim 1 , wherein said wound anode roll of an anode active material contains (a) a layer of supporting solid substrate having two primary surfaces wherein either one or both of said primary surfaces are coated with said anode active material, an optional conductive additive, and an optional binder or (b) a layer of supporting porous substrate having pores that are impregnated with said anode active material, an optional conductive additive, and an optional binder.

10. The rolled supercapacitor of claim 1 , wherein said wound cathode roll of a cathode active material contains (a) a layer of supporting solid substrate having two primary surfaces wherein either one or both of said primary surfaces are coated with said cathode active material, an optional conductive additive, and an optional binder or (b) a layer of supporting porous substrate having pores that are impregnated with said cathode active material, an optional conductive additive, and an optional binder.

11. The rolled supercapacitor of claim 1 , wherein said electrolyte and said flakes in said anode or said cathode are assembled into an electrolyte-impregnated laminar graphite flake structure that is wound into said anode roll or said cathode roll, wherein said flakes are alternately spaced by thin electrolyte layers, having a thickness from 0.4 nm to 10 nm, and said laminar graphite flake structure has a physical density from 0.5 to 1.7 g/cm 3 and a specific surface area from 50 to 3,300 m 2 /g, when measured in a dried state of said laminar structure without the presence of said electrolyte.

12. The rolled supercapacitor of claim 1 , wherein said liquid electrolyte contains an aqueous electrolyte, an organic electrolyte, an ionic liquid electrolyte, or a mixture of an organic and an ionic electrolyte.

13. A rolled supercapacitor comprising an anode current collector, an anode supported by said anode current collector, a cathode, a cathode current collector supporting said cathode, an ion-permeable separator that electronically separates said anode and said cathode, and an electrolyte in ionic contact with said anode and said cathode, wherein the anode and/or the cathode contains a wound roll of an electrolyte-impregnated laminar graphite structure, which is composed of multiple graphite flakes of graphite worms or expanded graphite being alternately spaced by thin electrolyte layers, less than 5 nm in thickness, and said multiple graphite flakes are substantially aligned along a desired direction perpendicular to said separator, and wherein said laminar graphite structure has a physical density from 0.5 to 1.7 g/cm 3 and a specific surface area from 50 to 3,300 m 2 /g, when measured in a dried state of said laminar graphite structure without the presence of said electrolyte.

14. A supercapacitor electrode roll, having a roll length, roll width, and roll thickness and containing an electrolyte-impregnated laminar graphite structure, which is composed of multiple graphite flakes of exfoliated graphite or expanded graphite being alternately spaced by thin electrolyte layers, from 0.3 nm to 10 nm in thickness, wherein multiple graphite flakes are substantially aligned along a desired direction parallel to said roll length and roll width and perpendicular to said roll thickness, and wherein said laminar graphite structure has a physical density from 0.5 to 1.7 g/cm 3 and a specific surface area from 50 to 3,300 m 2 /g, when measured in a dried state of said laminar graphite structure without said electrolyte.

15. The rolled supercapacitor of claim 1 , which is a lithium-ion capacitor or sodium-ion capacitor, wherein said cathode contains said wound cathode roll of a cathode active material having flakes that are oriented substantially parallel to the plane defined by said cathode roll length and said cathode roll width; and said anode contains a pre-lithiated anode active material or a pre-sodiated anode active material.

16. The rolled supercapacitor of claim 15 , wherein said anode contains a roll of a layer or two layers of a pre-lithiated anode active material or pre-sodiated anode active material layer coated on a solid or porous supporting substrate.

17. The rolled supercapacitor of claim 13 , which is a lithium-ion capacitor or sodium-ion capacitor, wherein said cathode contains said wound cathode roll of a cathode active material having isolated graphene sheets that are oriented substantially parallel to the plane defined by said cathode roll length and said cathode roll width; and said anode contains a pre-lithiated anode active material or a pre-sodiated anode active material.

Assignees

• Nanotek Instruments Inc
• Nanotek Instr Group Llc

Inventors

• Zhamu Aruna
• Jang Bor Z

Classifications

• H01G11/82

  Fixing or assembling a capacitive element in a housing, e.g. mounting electrodes, current collectors or terminals in containers or encapsulations · CPC title

• H01G11/24

  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 title

• H01G11/70

  characterised by their structure · CPC title

• H01G11/66

  Current collectors · CPC title

• H01G11/58

  Liquid electrolytes · CPC title