Active carbon for preparing carbon electrode of super capacitor and preparation method thereof

Abstract

The invention discloses an active carbon for preparing a carbon electrode of a super capacitor and a preparation method thereof. The average particle size of active carbon particles is between 15 and 30 mu m, the specific surface area of the active carbon particles is between 3,000 and 3,400 m<2> / g and pore channels with pore diameters of between 2 and 5 nanometers account for 25 to 32 percent of all pore channels in the particles. The preparation method comprises the following steps of: mixing an amphipathic carbon material serving as a precursor and potassium hydroxide (KOH) and deionized water and stirring the mixture to obtain solution; drying the solution to obtain a solid mixture; and activating, washing, and drying the washed solid mixture to obtain the active carbon. The active carbon and the preparation method have the advantages that: the process for preparing the active carbon is simple; the amphipathic carbon material is soluble in water and is easy to be uniformly mixed with KOH, so not only the using amount of KOH is reduced but also the uniformity and high efficiency of an activating process are improved; and the prepared active carbon has a large specific surface area, high occupation ratio of the pore channels with particle sizes of between 2 and 5 nanometers in the particles, high specific capacity for manufacturing the electrode of the super capacitor and excellent heavy current performance.

Description

technical field [0001] The invention relates to an activated carbon used for preparing supercapacitor carbon electrodes and a preparation method thereof, belonging to supercapacitor electrode technology. Background technique [0002] Supercapacitors have the advantages of high power density of ordinary capacitors and high energy density of secondary batteries. They can be charged and discharged quickly and have a long life. They are considered as an energy storage device between secondary batteries and capacitors. It has large capacitance, low leakage current, good voltage memory, simple charging and discharging and many cycles. It can be used in the backup power supply of microcomputer memory, automobile starting device and clean energy systems such as solar energy and wind energy, and has become a research hotspot that has attracted wide attention in recent years. [0003] Porous carbon materials have attracted much attention in the field of supercapacitors due to their l...

AI Technical Summary

Problems solved by technology

However, in the above method, due to the large particle size of the precursor itself (micron level), it takes a certain amount of time for the activator to reach the inside of the particle and the light components generated by activation to diffuse out of the particle during the activation process.

This activation process is often uneven, and the generated light components may be pyrolyzed inside the particles, blocking the already formed microporous structure

Therefore, in order to obtain activated carbon electrode materials with high specific surface area and large capacity, a relatively large amount of activator is required, which causes problems such as high cost and environmental pollution.

In addition, activated carbons obtained from traditional precursors are usually microporous materials, and the rate performance of supercapacitors assembled with these materials is significantly reduced under the condition of high current charge and discharge.

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