Humic acid-bonded metal foil film current collector and battery and supercapacitor containing same
A humic acid-bonded metal foil current collector in a battery or supercapacitor, comprising: (a) a thin metal foil having two opposed but parallel primary surfaces; and (b) a thin film of humic acid (HA) or a mixture of HA and graphene, having hexagonal carbon planes, wherein HA or both HA and graphene are chemically bonded to at least one of the two primary surfaces; wherein the thin film has a thickness from 10 nm to 10 μm, an oxygen content from 0.01% to 10% by weight, an inter-planar spacing of 0.335 to 0.50 nm between hexagonal carbon planes, a physical density from 1.3 to 2.2 g/cm 3 , all hexagonal carbon planes being oriented substantially parallel to each other and parallel to the primary surfaces, exhibiting a thermal conductivity greater than 500 W/mK, and/or electrical conductivity greater than 1,500 S/cm when measured alone without the metal foil.
1. A humic acid-bonded metal foil current collector for use in a battery or supercapacitor, said current collector comprising:
(a) a thin metal foil having a thickness from 1 μm to 30 μm and two opposed but substantially parallel primary surfaces; and
(b) at least one thin film containing humic acid (HA) and graphene oxide sheets, wherein said thin film comprising humic acid and graphene oxide sheets is chemically bonded to at least one of said two opposed primary surfaces of said metal foil;
wherein said thin film containing humic acid (HA) and graphene oxide sheets, when measured alone, has a physical density greater than 1.6 g/cm 3 , and/or a tensile strength greater than 30 MPa.
2. The current collector of claim 1 , wherein each of said two opposed primary surfaces is chemically bonded with said thin film containing humic acid (HA) and graphene oxide sheets.
3. The current collector of claim 1 , wherein said thin film containing humic acid (HA) and graphene oxide sheets is chemically bonded to at least one of said two opposed primary surfaces of said metal foil without using a binder or adhesive.
4. The current collector of claim 1 , wherein said thin film containing humic acid (HA) and graphene oxide sheets is bonded to at least one of said two opposed primary surfaces of said metal foil using a binder or adhesive.
5. The current collector of claim 4 , wherein said binder or adhesive is an electrically conductive material selected from an intrinsically conductive polymer, pitch, amorphous carbon, or carbonized resin.
6. The current collector of claim 1 , wherein said thin metal foil has a thickness from 4 to 12 μm and said thin film containing humic acid (HA) and graphene oxide sheets has a thickness from 20 nm to 2 μm.
7. The current collector of claim 1 , wherein said at least one primary surface does not contain a layer of passivating metal oxide thereon.
8. The current collector of claim 1 , wherein said metal foil is selected from Cu, Ti, Ni, stainless steel, Al foil, or a combination thereof.
9. The current collector of claim 1 , wherein said thin film containing humic acid (HA) and graphene oxide sheets has an oxygen content from 1% to 5% by weight.
10. The current collector of claim 1 , wherein said thin film containing humic acid (HA) and graphene oxide sheets has an oxygen content less than 1%, an inter-planar spacing less than 0.345 nm, and an electrical conductivity no less than 3,000 S/cm.
11. The current collector of claim 1 , wherein said thin film containing humic acid (HA) and graphene oxide sheets has an oxygen content no greater than 0.05%, an inter-planar spacing less than 0.336 nm, a mosaic spread value no greater than 0.7, and an electrical conductivity no less than 8,000 S/cm.
12. The current collector of claim 1 , wherein said thin film containing humic acid (HA) and graphene oxide sheets has an inter-planar spacing less than 0.336 nm, a mosaic spread value no greater than 0.4, and an electrical conductivity greater than 10,000 S/cm.
13. The current collector of claim 1 , wherein said thin film containing humic acid (HA) and graphene oxide sheets exhibits an inter-planar spacing less than 0.337 nm and a mosaic spread value less than 1.0.
14. The current collector of claim 1 , wherein said thin film containing humic acid (HA) and graphene oxide sheets is obtained by depositing a suspension of HA or a mixture of HA and graphene sheets onto said at least one primary surface under the influence of an orientation-controlling stress to form a layer of HA or a mixture of HA and graphene sheets and then heat-treating said layer at a heat treatment temperature from 80° C. to 1,500° C.
15. The current collector of claim 1 , wherein said thin film containing humic acid (HA) and graphene oxide sheets contains chemically bonded humic acid molecules or chemically merged humic acid and graphene planes that are parallel to one another.
16. The current collector of claim 1 , wherein said thin film containing humic acid (HA) and graphene oxide sheets is a continuous length film having a length no less than 5 cm and a width no less than 1 cm.
17. The current collector of claim 1 , wherein said thin film containing humic acid (HA) and graphene oxide sheets, when measured alone, has a physical density greater than 1.8 g/cm3, and/or a tensile strength greater than 50 MPa.
18. The current collector of claim 1 , wherein said thin film containing humic acid (HA) and graphene oxide sheets, when measured alone, has a physical density greater than 2.0 g/cm 3 , and/or a tensile strength greater than 80 MPa.
19. A rechargeable lithium battery or lithium-ion battery containing the current collector of claim 1 as an anode current collector and/or a cathode current collector.
20. A rechargeable lithium battery containing the current collector of claim 1 as an anode current collector or a cathode current collector, which lithium battery is a lithium-sulfur cell, a lithium-selenium cell, a lithium sulfur/selenium cell, a lithium-air cell, a lithium-graphene cell, or a lithium-carbon cell.
21. A capacitor containing the current collector of claim 1 as an anode current collector or a cathode current collector, which capacitor is a symmetric ultracapacitor, an asymmetric ultracapacitor cell, a hybrid supercapacitor-battery cell, or a lithium-ion capacitor cell.
22. A humic acid-bonded metal foil current collector for use in a battery or supercapacitor, said current collector comprising:
(c) a thin metal foil having a thickness from 1 μm to 30 μm and two opposed but substantially parallel primary surfaces; and
(d) at least one thin film containing humic acid (HA) and graphene oxide sheets, wherein said thin film comprising humic acid and graphene oxide sheets is chemically bonded to at least one of said two opposed primary surfaces of said metal foil;
wherein said thin film containing humic acid (HA) and graphene oxide sheets has a thickness from 5 nm to 10 μm, an oxygen content from 0.01% to 0.1% by weight, a physical density from 1.3 to 2.2 g/cm 3 , humic acid and graphene oxide sheets being oriented substantially parallel to each other and parallel to said primary surfaces, an inter-planar spacing of 0.335 to 0.337 nm, a thermal conductivity greater than 250 W/mK, and an electrical conductivity no less than 5,000 S/cm when measured alone without said thin metal foil.
23. A humic acid-bonded metal foil current collector for use in a battery or supercapacitor, said current collector comprising:
(a) a thin metal foil having a thickness from 1 μm to 30 μm and two opposed but substantially parallel primary surfaces; and
(b) at least one thin film containing humic acid (HA) and graphene oxide sheets, wherein said thin film comprising humic acid and graphene oxide sheets is chemically bonded to at least one of said two opposed primary surfaces of said metal foil;
wherein said thin film contains chemically functionalized humic acid (CHA) containing a chemical functional group selected from a polymer, SO 3 H, NH 2 , R′CHOH, CN, COCl, halide, COSH, SH, COOR′, SR′, SiR′ 3 , Si(—OR′—) y R′ 3 -y, Si(—O—SiR′ 2 —)OR′, R″, Li, AlR′ 2 , Hg—X, TlZ 2 and Mg—X; wherein y is an integer equal to or less than 3, R′ is hydrogen, alkyl, aryl, cycloalkyl, or aralkyl, cycloaryl, or poly(alkylether), R″ is fluoroalkyl, fluoroaryl, fluorocycloalkyl, fluoroaralkyl or cycloaryl, X is halide, and Z is carboxylate or trifluoroacetate, or a combination thereof.