Introduction to the classification of supercapacitors
There are many types of supercapacitors , which can be divided into various products according to different methods. The following is a brief introduction.
According to the principle, it is divided into electric double layer supercapacitor and pseudocapacitor supercapacitor:
Electric double layer supercapacitor
1. Activated carbon electrode material, the activated carbon material with high specific surface area is selected to prepare the electrode by molding.
2. Carbon fiber electrode materials, select activated carbon fiber forming materials, such as cloth, felt, etc., to prepare electrodes by strengthening, spraying or melting metal to enhance their conductivity.
3. Carbon aerogel electrode material, select precursor material to prepare gel, and obtain electrode material through carbonization activation.
4. Carbon nanotube electrode materials, carbon nanotubes have excellent mesoporous function and electrical conductivity, and carbon nanotube materials with high specific surface area can be used to make very good supercapacitor electrodes.
The above electrode materials can be made into:
1. Plate-type supercapacitors, in the button-type system, mostly use plate-shaped and disc-shaped electrodes, and there are also high-voltage supercapacitors that are combined in series with multiple layers, which can reach operating voltages above 300V.
2. The winding type solvent capacitor is made by coating the electrode material on the current collector and winding. This type of capacitor generally has a larger capacitance and a higher power density.
Contains metal oxide electrode materials and polymer electrode materials. Metal oxides include NiOx, MnO2, V2O5, etc. as positive electrode materials, and activated carbon is used as negative electrode materials for supercapacitors. Conductive polymer materials include PPY, PTH, PAni, PAS, PFPT, etc. Electrodes are prepared by doping P-type or N-type or P/N-type to prepare supercapacitors. This type of supercapacitor has a very high energy density. Except for the NiOx type, most of the other types are in the research stage and have not yet completed industrial production.
By electrolyte type
Can be divided into aqueous electrolytes and organic electrolyte types:
1. Acidic electrolyte, 36% H2SO4 aqueous solution is mostly used as the electrolyte.
2. Alkaline electrolyte, generally strong bases such as KOH and NaOH are used as electrolytes, and water is used as solvent.
3. Neutral electrolyte, generally choose KCl, NaCl and other salts as electrolyte, water as solvent, mostly used for electrolyte of manganese oxide electrode material.
Organic electrolytes generally use LiClO4 as a typical representative of lithium salts, TEABF4 as a typical representative of quaternary ammonium salts, etc. as electrolytes, organic solvents such as PC, ACN, GBL, THL and other organic solvents are used as solvents. The electrolyte is close to saturation solubility in the solvent.