As a new type of product, supercapacitor has been updated and adjusted in structure, material and performance. According to different contents, the classification methods of supercapacitors are different. At present, the classification of supercapacitors generally refers to the principle of capacitors, electrolyte and other two major elements, each type of supercapacitors can be divided into different categories.
(1) According to the principle of classification. According to different working principles, supercapacitors can be divided into two categories: electric double layer supercapacitors and pseudo capacitor supercapacitors. The electric double layer supercapacitor has been reprocessed on manufacturing materials, such as activated carbon electrode materials, electrodes made of activated carbon materials with high specific surface area, and electrodes made of carbon aerogel electrodes, and gels combined with precursor materials, and then carbonized and activated as electrodes. Metal oxide electrode materials and polymer electrode materials are generally used in pseudo capacitor supercapacitors. The former includes NiOx, MnO2 and V2O5 used as cathode materials, and activated carbon as anode materials. The latter includes PPy, PTH, PANI, PAS, PFPT, etc. which are doped with p-type or n-type or P / N type to prepare electrodes.
(2) According to electrolyte classification. Electrolyte is a kind of compound with conductivity after being dissolved in aqueous solution. Electrolytes in supercapacitors include water-based electrolytes and organic electrolytes. The common electrolytes of water-based electrolytes are acidic, alkaline and neutral. The composition of electrolytes with different characteristics is also different. For example, the acid electrolyte is composed of 36% H2SO4 aqueous solution, and the alkaline electrolyte is composed of KOH, NaOH and other strong bases. Generally, LiClO4 based lithium salt and teabf4 based quaternary amine salt are selected as organic electrolytes. Sometimes corresponding solvents, such as PC, ACN, GBL and THL, can be added according to the needs of use, which can significantly improve the performance of supercapacitors.
According to the electrolyte classification method of supercapacitors, we can also combine the specific state of electrolyte classification. For example: according to the solid state and liquid form of electrolyte, it can be divided into solid electrolyte super capacitor and liquid electrolyte super capacitor.