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High ratio surface squama graphite for the electrochemical capacitor of the electrode material

A flake graphite, high specific surface technology, applied in electrolytic capacitors, capacitors, capacitor electrodes, etc., can solve the problems of low capacity, high cost, etc., and achieve high output power, excellent conductivity, and low cost

Inactive Publication Date: 2009-11-04
FUDAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

As an electrode material for electrochemical capacitors, this commercial activated carbon suffers from high cost and low capacity

Method used

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  • High ratio surface squama graphite for the electrochemical capacitor of the electrode material

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] Using natural graphite as raw material, high specific surface flake graphite sample 1 (HSAFG-1) was obtained by mechanical ball milling for 3 hours, with a specific surface area of ​​210m 2 / g, I(1360) / I(1580) was 0.4. Mix HSAFG-1 and binder polytetrafluoroethylene PTFE at a mass ratio of 95:5, use isopropanol as a dispersant, stir well to form a paste, apply it on Ni foil, and bake it at 120°C for 12 hours after rolling. The electrode density is 1.8g / cm 3 . The electrolyte is the most commonly used 6M KOH aqueous solution in the water system. With Ag / AgCl as the reference and Pt sheet as the counter electrode, constant current charge and discharge tests are carried out in the range of -0.2 ~ -1.0V vs. Ag / AgCl. Its specific capacity is calculated by the formula C=It / (Vm), where C(F / g) is the single electrode capacity, I(A) is the discharge current, t(s) is the discharge time, V(V) is the discharge voltage, and m(g) is the mass of the high specific surface graphite ma...

Embodiment 2

[0022] Using commercial activated carbon AC (Mitsubishi Corporation of Japan) as the electrode active material, the specific surface area is 2100m 2 / g, electrode composition is activated carbon: PTFE=95: 5, electrolytic solution adopts 6M KOH aqueous solution, tests this activated carbon with the same method in embodiment 1, and its result is listed in table 1. Its capacity is 144F / g. Because activated carbon has highly developed inner pores, it has high porosity and low electrode density, only 0.5g / cm 3 . Moreover, the proportion of micropores (2 , while the unit surface specific capacity of HSAFG-1 in Example 1 reaches 22 μF / cm 2 , it can be seen that the surface utilization of graphite material is higher than that of activated carbon. At the same time, the conductivity of activated carbon is much worse than that of graphite material, so its rate characteristic is worse than that of HSAFG-1.

Embodiment 3

[0024] Using natural graphite as raw material, high specific surface flake graphite sample 2 (HSAFG-2) was obtained by mechanical ball milling for 6 hours, with a specific surface area of ​​590m 2 / g, I(1360) / I(1580) was 1.0. Prepare electrode with the method in embodiment 1, electrode density is 1.3g / cm 3 , using 6M KOH as the electrolyte to charge and discharge in the range of -0.2~-1.0V vs.Ag / AgCl, the results are listed in Table 1. As the specific surface area increases, the electrode density decreases, but the specific capacity increases rapidly to 110F / g. Compared with Example 1, the rate performance decreases slightly, but it is still better than activated carbon.

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Abstract

The invention belongs to fields of electrochemical capacitor technique, specially an electrochemical capacitor which uses high specific surface scaly graphite as electrode material. The structure of the electrochemical capacitor is the same as general electrochemical capacitor, thereinto the anode film and / or cathode film includes high specific surface flaky graphite material or mixture of high specific surface flaky graphite and other material, this graphite electrode material possesses specific surface area which is more than general graphite: 100-1500m2 / g. The surface comprises flat surface, section, end surface and irregular hole. The electrode material can form charge electric double layer to store energy at interface of electrode / solution just as the active carbon, and it possesses more high bulk density, electron conductivity and charge-discharge coulomb efficiency than current porous active carbon, the combination property is excellent than current active carbon, and cost is further less than current trade active carbon, it can be used to produce high-energy-density, large power and long life electrochemical capacitor.

Description

technical field [0001] The invention belongs to the technical field of electrochemical capacitors, in particular to an electrochemical capacitor using flake graphite with a high specific surface as an electrode material. Background technique [0002] A capacitor is a device and device that can store electrical energy. Because its use can prevent electronic instruments and equipment from erroneous actions caused by instantaneous power cuts or occasional voltage drops, it is widely used as a backup power supply for audio-video equipment: Tuners, telephones, fax machines and computers and other communication equipment and household appliances. The research on capacitors began in the 1930s. With the development of the electronics industry, it has experienced the development of electrolytic capacitors, ceramic capacitors, organic film capacitors, aluminum electrolytic capacitors, tantalum electrolytic capacitors and electrochemical capacitors. [0003] In 1879, Helmholz's work d...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01G9/042H01G9/058H01G9/04H01G9/022H01G9/00H01M4/00H01M14/00H01G11/24
CPCY02E60/13
Inventor 夏永姚李会巧
Owner FUDAN UNIV