Supercapacitors and method for fabricating the same

• US 6,512,667 B2
• Filed: 02/15/2001
• Issued: 01/28/2003
• Est. Priority Date: 02/01/2001
• Status: Expired due to Fees

• Current Assignee: Luxon Energy Devices Corporation
• Original Assignee: Luxon Energy Devices Corporation
• Inventors: Shiue, Lih-Ren, Chao, Ching-Wen, Jou, Jiung-Jau, Wu, Dien-Shi
• Primary Examiner(s): Dinkins, Anthony
• Assistant Examiner(s): HA, NGUYEN T
• Application Number:
  US09/784,718
• Publication Number:
  US 20020163770A1
• Time in Patent Office: 712 Days
• Field of Search: 361/502, 361/503, 361/504, 361/508, 361/509, 361/516, 361/528, 361/512, 361/518, 361/505, 361/522, 361/523, 429/218, 429/40, 429/44, 429/46, 429/128, 429/129
• US Class Current: 361/502
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: H01G 11/26 characterised by their structure, e.g. multi-layered, porosity or surface features
• CPC Class Codes: H01G 11/46 Metal oxides
• CPC Class Codes: H01G 11/72 specially adapted for integration in multiple or stacked hybrid or EDL capacitors
• CPC Class Codes: H02J 1/14 Balancing the load in a network
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

Using thin-films of iron oxide as the active material of electrodes, supercapacitors are fabricated on various substrates in different shapes. By chemical oxidation the iron-oxide film is formed directly and conformably on the substrates in a short period of cooking. The iron oxide has a chemical composition of Fe_xO_yH_z, where 1.0≦x≦3.0, 0.0≦y≦4.0, and 0.0≦z≦1.0. Substrates, as the current collector, tested includes Al, Ti, Fe, Cu and Ni. Measurements by cyclic voltammetry indicates that the iron-oxide electrodes in a selected electrolyte can store charges as high as 0.5 F/cm² or 417 F/g of the electrode materials. Supercapacitors as prepared are economical and can be used as enclosure housings for portable electronics, power tools, and batteries. The supercapacitors can also be integrated with the frames and chassis of electric vehicles.

Claims

1. An electrochemical capacitor with capacitance greater than or equal to 0.1 F, the capacitor comprising:

a first electrode of the capacitor that comprises at least one electrode material having a chemical composition of Fe_xO_yH_z, where 1.0≦

x≦

3.0, 0.0≦

y≦

4.0 and 0.0≦

z≦

1.0, wherein the first electrode in conformal shape is formed on a current collector and the current collector is at least a portion of a peripheral surface of one selected from the group consisting of case, chassis, compartment, cover, housing, and frames of one selected from the group consisting of appliance, battery, device, equipment, instruments, electric automobile, bicycle, motorcycle, scooter and wheelchair;

a second electrode formed in conformal shape over the first electrode, wherein the second electrode can also include the same electrode material for the first electrode; and

a separator with an electrolyte formed between the first electrode and the second electrode, whereby a built-in electrochemical capacitor is formed thereon.

2. The electrochemical capacitor in accordance with claim 1, wherein the electrode material Fe_xO_yH_z includes one selected from the group consisting of Fe, FeO, Fe₃O₄, Fe₂O₃, FeO(OH) and combinations thereof, wherein the electrode material is an in-situ structure grown on the current collector.

3. The electrochemical capacitor in accordance with claim 1, wherein the current collector of the electrochemical capacitor comprises one selected from the group consisting of iron, steel, aluminum, titanium, copper, nickel, glass, plastics and ceramics, whereby the current collector is to support the electrode material Fe_x,O_yH_z for delivering capacitances greater than or equal to 0.1 F to loads.

4. An electrochemical capacitor, comprising at least two electrodes which are machine-folded plates in conformal to an outer shape of an appliance, one of the electrodes utilizes a current collector that is the appliance selecting from the group consisting of a case, a chassis, a cover, a frame or a housing of electric automobile, bicycle, motorcycles, scooter, and wheelchairs, die-pressed plates and extruded plates.

5. The electrochemical capacitor in accordance with claim 4, wherein the plates have thickness ≧

0.1 mm.

6. An electrochemical capacitor wherein at least two electrodes are wave-shaped plates in conformal to an outer shape of an appliance, in which one of the electrodes utilizes a current collector that is the appliance selecting from the group consisting of a case, a chassis, a cover, a frame or a housing of electric automobile, bicycle, motorcycles, scooter, and wheelchairs.

7. The electrochemical capacitor in accordance with claim 6, wherein the plates have thickness ≧

0.1 mm.

8. An electrochemical capacitor wherein at least two electrodes are two concentric tubes in conformal to an outer shape of an appliance, in which one of the electrodes utilizes a current collector that is the appliance selecting from the group consisting of a case, a chassis, a cover, a frame or a housing of electric automobile, bicycle, motorcycles, scooter, and wheelchairs.

9. The electrochemical capacitor in accordance with claim 8, wherein the two tubes include a round shape, in which both the electrodes are in a round shape.

10. The electrochemical capacitor in accordance with claim 8, wherein the two tubes include a triangle shape, in which both the electrodes are in the triangle shape.

11. The electrochemical capacitor in accordance with claim 8, wherein the two tubes include a square shape, in which both the electrodes are in a square shape.

12. The electrochemical capacitor in accordance with claim 8, wherein the two tubes include a rectangle shape, in which both the electrodes are in rectangle shape.

13. The electrochemical capacitor in accordance with claim 8, wherein the two tubes include a polyhedral shape, in which both the electrodes are in polyhedral shape.

14. An electrochemical capacitor with capacitance greater than or equal to 0.1 F, which is integrated with one side or four sides of cases, chassis, compartments, covers, and housings for one selected from the group consisting of appliances, batteries, devices, equipment and instruments.

15. An electrochemical capacitor with capacitance greater than or equal to 0.1 F, which is conformally integrated with at least a portion of a peripheral surface of one selected from the group consisting of case, chassis, compartment, cover, and housing for one selected from the group consisting of appliance, battery, device, equipment, and instruments, whereby the electrochemical capacitor is a built-in capacitor structure.

16. An electrochemical capacitor with capacitance greater than or equal to 0.1 F, wherein the electrochemical capacitor is integrated with at least a portion of a peripheral surface of a frame or a chassis for one selected from the group consisting of electric automobile, bicycle, motorcycle, scooter and wheelchair, whereby the electrochemical capacitor is a built-in capacitor structure.