Potential Scan Rate Effect on Specific Capacitance

3 Potential Scan Rate Effect on Specific Capacitance 

As discussed in Chapter 3, two parallel processes within the electrode layer of a pseudocapacitor contribute to the overall capacitance. The first is doublelayer charging and discharging, and the second is from faradic electrochemical reactions. This kind of device is called a pseudosupercapacitor, because the electrode charging-discharging process involves electrochemical reactions giving rise to pseudocapacitance. For an ideal electrode layer inside a 

According to the definition of capacitance and Equation (71), Equation (717) can be alternatively expressed as 

Equation (718) suggests that the momentary current recorded on the active layer-coated electrode of the pseudosupercapacitor is the sum of the doublelayer charging or discharging current ifi(E)) and the electrochemical reaction current Note that both currents are functions of the electrode 

For the Fe(II)-Nx/Fe(III)-Nx redox wave that is electrochemically active in the potential range of -0.56 to 0.76 V ( 2 - Ei = 0.20 V in this case), according to the definition of pseudocapacitance provided in Chapter 3, the specific capacitance of the electrochemical active material 

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