Preparation method of modified activated carbon material for capacitor

Abstract

The invention discloses a preparation method of a modified activated carbon material for a capacitor. The preparation method comprises the following steps: (1) polishing, drying and crushing a carbonsource; (2) activating the raw materials through a phosphoric acid solution to obtain a primary activated product; (3) mixing the precursor powder with the primary activation product, and activating with potassium hydroxide to obtain a secondary activation product; and (4) adding the secondary activation product into a saturated lead nitrate solution, carrying out ultrasonic dispersion, stirring and performing vacuum filtration to obtain a filter cake, and carrying out heat treatment to obtain the material. The preparation method of the activated carbon is simple; the preparation method is simple in process, wide in raw material source and suitable for large-scale production, a secondary activation process is adopted in the preparation process, precursor powder with high content of heteroatoms such as nitrogen and oxygen is added into the activated carbon, the specific surface area is further increased, micropores are enriched in the surface, the specific capacitance of the material isimproved, and the use performance of the material is enhanced.

Description

technical field [0001] The invention belongs to the technical field of activated carbon materials, in particular to a method for preparing a modified activated carbon material used in capacitors. Background technique [0002] Activated carbon, also known as activated carbon, refers to an amorphous carbonaceous material with high porosity and large specific surface area (ie, surface area per unit mass). It is usually manufactured by pyrolysis of different carbonaceous substances followed by activation by physical or chemical processes, and it can exist in many different forms such as granules, powder, fibrous material, cloth, etc. Activated carbons have been widely used in industrial fields, such as electrode materials for supercapacitors, as adsorbents for water and gas purification, and as inorganic metals due to their good porosity, high specific surface area, and good thermal and chemical stability. catalyst or catalyst support. With the development of society and the i...

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Problems solved by technology

However, the introduction of activated carbon into the above materials will also bring some other problems. For example, in lead-acid batteries, the hydrogen evolution overpotential of activated carbon is lower than that of lead, which will accelerate the hydrogen evolution reaction in the later stage of battery charging, thereby causing the electrolyte to lose water. At the same time The high specific surface activated carbon in the electrode may have side reactions, generate products such as carbon dioxide and carbon monoxide, and consume a large amount of water in the electrolyte, resulting in a decrease in material performance