Energy pseudocapacitance

Pseudocapacitance is used to describe electrical storage devices that have capacitor-like characteristics but that are based on redox (reduction and oxidation) reactions. Examples of pseudocapacitance are the overlapping redox reactions observed with metal oxides (e.g., RuO,) and the p- and n-dopings of polymer electrodes that occur at different voltages (e.g. polythiophene). Devices based on these charge storage mechanisms are included in electrochemical capacitors because of their energy and power profiles. 

Summarizing the above, it may be stated that activated carbons and pseudocapacitive materials in EC electrode structure are responsible for the energy storage parameters (specific energy), while non-active highly conductive carbon additives are responsible for the electrode internal resistance (EC specific power). 

Conway BE, Birss V, Wojtowicz. The role and utilization of pseudocapacitance for energy storage by supercapacitors. J. Power Sources 1997 66 1-14. 

In general, two modes of energy storage are combined in electrochemical capacitors (1) the electrostatic attraction between the surface charges and the ions of opposite charge (EDL) and (2) a pseudocapacitive contribution which is related with quick faradic charge transfer reactions between the electrolyte and the electrode [7,8], Whereas the redox process occurs at almost constant potential in an accumulator, the electrode potential varies proportionally to the charge utilized dr/ in a pseudocapacitor, which can be summarized by Equation 8.5 ... 

Wang J, Polleux J, Lim J, Dunn B. Pseudocapacitive contributions to electrochemical energy storage in Ti02 (anatase) nanoparticles. J Phys Chem C. 2007 111 14925-31. 

Pseudocapacitance and conversion reactions can dramatically increase the energy storage capabUity of secondary batteries. How are these phenomena dependent on nanoscale structures ... 

Studies on the topic of capacitive storage are oriented toward the increase in energy density of supercapacitors by working on carbon, pseudocapacitive materials and electrolytes. 

AUG 13] Augustyn V., Come J., Low M.A., et al, Evidence of intercalation pseudocapacitance in high-rate lithium-ion energy storage materials . Nature Materials, vol. 6, pp. 518-522, 2013. 

At present, a great number of research works on development and improvement of electrochemical supercapacitors (ECSCs) are published. As pointed out above, ECSCs are subdivided into EDLCs, in which the energy of EDL recharging is used pseudocapacitors (PsCs), in which pseudocapacitance of fast quasireversible faradaic... 

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