[EChem fundamentals] Types of pseudocapacitance

In this video, I will talk about three types of mechanisms that give rise to pseudocapacitance as defined by Conway. The content of the video is made based on the review article: Simon Fleischmann, James B. Mitchell, Ruocun Wang, Cheng Zhan, De-en Jiang, Volker Presser, and Veronica Augustyn. Chem. Rev. 2020, 120, 6738−6782.
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[@rbtao1985]

Good job. Thanks a lot. Please keep updating new videos

[@kuldeepmaurya4713]

Maim how to calculate double layer capicitance from impidence data.
Plz tell me

[@arunkrishnan5752]

Please do one video on experimental demonstration of HER and related calculations.(ECSA, TOF etc.)

[@NitinKMSP]

In the redox pseudocapacitance example you showed, the hydrogen ion (which entered the electrode and got reduced) did not leave the electrode. Instead, it is 'locked' in the electrode. So is the process Faradaic or non-Faradaic ?

[@NitinKMSP]

Please explain my doubt

[@EChem_Channel]

@@NitinKMSP Hi Nitin, sorry for the late reply. If the material is reduced, the process is Faradaic.

[@EChem_Channel]

I would add that in this case, the proton didn't get reduced - it is the Ru in the RuO2-0.5H2O that is reduced. I am not sure what you mean by 'locked' in the electrode.

[@NitinKMSP]

@@EChem_Channel Thank you for reply
In this article,
Biesheuvel, P. M., Porada, S., & Dykstra, J. E. (2018). The difference between Faradaic and non-Faradaic electrode processes. arXiv preprint arXiv:1809.02930.
it is mentioned that, to have a Faradaic process, there must be an electrode reaction where an ion or atom is reduced or oxidized to another species.
In addition the reactant must come from outside the electrode, and the product of the reaction must leave the electrode again. It is also mentioned that, if the reacting species is oxidized/reduced in the electrode, but then stays there, i.e., ‘is locked in the electrode’, the process is non-Faradaic.
In the redox pseudocapacitance example you mentioned, the reacting species, i.e., the hydrogen ion didn't leave the electrode. My doubt is, then how the process is
Faradaic?

[@EChem_Channel]

@@NitinKMSP Thanks for providing the context. I do remember this arXiv article, which stirred quite some discussions a few years ago. I think the "locked in the electrode" concept applies well to EDL charging, where the ions of opposite charge will stay at the surface and be locked there. However, since there is the reduction of Ru, and the charge transfer follows Faraday's law of electrolysis, the proton intercalation here is Faradaic. The definition of David Grahame was from 1952. I do think solid-state electrochemistry has developed a lot since then.