Episode #108: How do I use the Bode plot during EIS circuit fitting?

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 [email protected]. 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 and information about the livestream 06:08 - Livestream starts 08:29 - How do you interpret and use Bode plots, specifically with regard to supercapacitors? 19:45 - Which is better to avoid battery dendrite formation, gel or aqueous electrolytes? 23:54 - What is the difference between equivalent series resistance and charge transfer resistance in EIS, and where are they located on a Nyquist plot? 29:30 - How do you find the potential window for CV? 37:29 - I'm working on solid polymer electrolytes with lithium salt. My cell is simply the electrolyte between two stainless steel electrodes, so no faradaic reactions. How would I circuit fit this system? 43:52 - Which battery parameter can be selected for decreasing battery degradation for EVs? 55:02 - For OER, when should we measure impedance? How many cycles are needed to activate the sample? 57:45 - As the semicircle diameter decreases, it means the system is less resistive, so does that mean having a depressed semicircle is better than a broad one in terms of resistivity as well? 1:01:08 - How do you fit a Nyquist plot with half a semicircle with a Warburg component? 1:06:44 - What is open circuit potential and how should we select it? 1:19:29 - Which is better for batteries, C-rate or current density? 1:20:43 - How is the theoretical capacity of a battery material like graphite determined? 1:28:35 - For liquid vs solid state electrolytes, does the frequency matter for EIS? I find for lower frequencies the plot starts to get noisy. 1:32:35 - Can I use GITT for diffusion analysis in any battery electrode with conversion chemistry, or is it restricted to intercalation chemistry only? 1:38:25 - What is the difference between a Daniell cell and a voltaic cell? 1:48:00 - If the Rct is decreasing after a stability test of a lithium ion battery coin cell, what does it mean? 1:53:18 - What is the point of using a Luggin capillary? Is it possible to make measurements without it but just use iR compensation?