Episode #97: Ask us anything about what potential you should pick for EIS

This is a Livestream Q&A/Ask Us Anything for answering YOUR questions on YouTube. In this Q&A session we will answer your electrochemistry research questions LIVE, as well as any other questions related personal topics like careers, academia, industry, or life in general.

We have compiled a database of all questions asked in our Ask Us Anything About Electrochemistry Livestreams, tagged by the question subject and linked with time stamps to the place in that week's Livestream. If you are interested in obtaining a copy of this database (MS Excel file), please reach out via comments here or directly to us at pinewire@pineresearch.com.

Check out https://aftermathlive.com, Pine Research's online electrochemical simulation software! Perfect for the classroom or research lab, licenses are available for simulating CV and bulk electrolysis of a variety of chemical and electrochemical reactions. Accessible on both PC and Mac!

Time stamps:
00:00 - Introduction
05:57 - Livestream starts
07:25 - I have Mott-Schottky data and it looks good on my computer software, but when I export it all the values are zero, why is this happening?
15:48 - What is the definition of overpotential?
17:44 - Why for battery research we measure EIS for Li/Li cells, and LSV for Li/Al cells, but Li/NCM is the most important kind of coin cell? Also what is the suitable range for measuring CV of coin cells?
23:36 - Explanation of thermodynamic potential
28:32 - What is Rct, and how does it differ from the Warburg element?
32:40 - What is the difference between 2-, 3-, and 4-electrode systems?
34:46 - Why run EIS with a potential that's not OCP? Will it cause a decrease in Rct?
39:12 - For EIS, what timing accuracies between ADC measurements are required for good output data? I have aims of ~10 ns at 200 kHz but don't know much about real system accuracies
45:14 - Will a self-assembled monolayer (SAM) on an electrode increase the solution resistance, the charge transfer resistance, or both?
50:08 - How do I get a proper EIS spectra for a multi-cell stack, as it's not coming out properly or making a semicircle?
54:17 - I am working on a solid polymer electrolyte and conducting EIS measurements. I don't know if there is a difference between doing tests from 80°C to 30°C, or from 30°C to 80°C. Does the order make a difference?
58:24 - I am new with electrochemical techniques like CV, LSV, DPV, SWV, etc. I am planning to work on biosensors. What methods should I use, and what are the differences between the above methods?
1:05:06 - How can we calibrate reference electrodes if we can't have a standard hydrogen electrode to use?
1:11:34 - Please suggest a stable redox mediator having a negative redox potential for my bioanode to achieve a high OCV when scaled up to a fuel cell
1:14:34 - I have a question about EIS. What should be the embedded equivalent circuit if I have a multiple layer (e.g., 3) electrode on top of stainless steel?
1:22:10 - Why do we get a peak in CV, and after the peak current even though we increase the potential why does the current decrease?
1:26:46 - Can you discuss the difference between Butler-Volmer kinetics and Marcus-Hush-Chidsey kinetics?
1:31:00 - What is the current to be multiplied with solution resistance to find uncompensated iR?
1:34:36 - I am working with Cu2O as a semiconductor photocatalyst. I perform an LSV test at 50 mV/s from -1 to 1.2 V to prove it's a semiconductor. I get a peak around 0.5 V in light, but what phenomenon is happening going up from 0.2 to 0.5 V to make a peak?
1:42:54 - I am working with single-layer graphene (SLG) devices and I'm observing a quasi-semicircle in high frequencies. I'm confident it's a contact resistance. How can I assure it's that and not another problem?
1:45:48 - I tried to measure the resistance of PiperION 60 µm anion-exchange membrane (AEM) in bicarbonate form at 60°C. Before CV and PEIS I set a CA at 2 V, and the measurement stopped after a few seconds due to current overload. I ran at 25°C and the value was half that measured at 60°C. Would too-high current be caused by high operating temperature? Also, what is a good equivalent circuit for membrane EIS data?
1:52:06 - What would be the approach to try to measure a very small faradaic current that is likely masked/hidden by charging current? Is DPV a good option?
1:53:15 - I'm doing EIS at -1.8 V vs Pt in non-aqueous media and at low frequency, and after the semicircle, the -Z" goes straight down. What can that be?
1:58:40 - Is iR compensation always necessary? Most catalysis studies do iR compensation but there is also 0.9, 0.95, or even 0.5 corrections. Is iR misused to overreport performance, or is it misunderstood?

Видео Episode #97: Ask us anything about what potential you should pick for EIS канала Pine Research Instrumentation, Inc.