pseudokapasitanssia

Pseudokapasitanssia, often translated as pseudocapacitance, refers to a phenomenon observed in certain electrochemical systems where a charge storage mechanism mimics the behavior of a capacitor, but is not a true dielectric-based capacitive process. Instead, it arises from faradaic reactions, which involve the transfer of electrons. These reactions, such as redox intercalation or surface adsorption/desorption of ions, can store charge at an electrode-electrolyte interface.

The term "pseudo" is used because the charge storage is not solely due to the accumulation of ions at the interface (as in an electrical double-layer capacitor, EDLC), but involves a chemical transformation. This leads to a higher charge storage density compared to EDLCs operating within a similar voltage window. Pseudocapacitive materials often exhibit a linear relationship between charge and voltage over a specific range, similar to a capacitor, but the underlying mechanism is distinct.

Common materials exhibiting pseudocapacitance include transition metal oxides and conducting polymers. For example, metal oxides like ruthenium oxide (RuO2) and manganese dioxide (MnO2) are well-known pseudocapacitive materials. Conducting polymers such as polyaniline and polypyrrole also display pseudocapacitive behavior due to doping and dedoping processes. The performance of pseudocapacitive devices is influenced by factors like the specific material, electrode structure, and electrolyte composition. Understanding pseudocapacitance is crucial for the development of advanced energy storage devices like supercapacitors.