Pseudo-faradic reactions

The most reported dopants which confer pseudo-capacitive properties to carbons are oxygen (Fig. 12.3) and nitrogen (Fig. 12.4). Some other studies described below have recently considered boron or phosphorous as pseudo-capacitive dopants. The nitrogenated and oxygenated functionalities can imdergo pseudo-faradic reactions, which can be pH-dependent or not, as presented in Fig. 12.10. The extent of the... 

O- and N-enriched nanocarbons demonstrate high capacitance values in KOH or H2SO4 due to the contribution of pseudo-faradic reactions. Another positive effect of doping is the broadening of the potential stability window. Composites of these carbons with carbon nanotubes withstand remarkable capacitance values at high current load. Hence, the N- and O-doped carbons open the opportunity of developing high-performance supercapacitors in aqueous electrolytes. 

Neutral electrolytes have been scarcely applied for carbon-based supercapacitors. Indeed, the capacitance values of activated carbons in neutral electrolytes are lower than in other aqueous electrolytes, suggesting that the pseudo-faradic redox reactions of O and N electroactive surface groups are depressed in comparison with acidic or basic electrolytes [25, 27, 57-59]. Therefore, it was concluded that oxygenated or nitrogenated functionalities are electrochemically inactive in neutral electrolytes and that only the formation of the electrical double layer contributes to the capacitance in this media. 

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