Dear Dr. Parastu Fardi ,

personally did electrochemical tests on different types of samples for research use, sometimes very small (uncoated, less than 1 cm2), incorporating them in cold resin followed by metallographic polishing and I still obtained significant results.

If possible, always work by comparison, so as to highlight the different behavior of the samples.

There are ASTM and ISO standards relating to electrochemical measurements on samples and cells and related methodology; some information you can find on the net.

I suggest you to have a look at the Gamry instruments notes, there are several, in particular I found the following very interesting:

-Rapid Electrochemical Assessment of Paint

Available at: https://www.gamry.com/application-notes/corrosion-coatings/rapid-electrochemical-assessment-of-paint/

My best regards, Pierluigi Traverso.

https://www.sciencedirect.com/topics/chemical-engineering/potentiodynamic-polarization

I did EIS using capillars with diameters in the order of tens of microns, but the best answer is: the (reasonably) larger the better. Small samples are often not representative for the all surface, as they might have more or less than the average defect density.

It depends on the results you expect to achieve, but in your case I suggest you to stay in a range between 2 and 6 cm in cell diameter.

Use a flat cell. No need to cut the sample.

Dear Dr. Fardi,

It is most commonly of mirror polished sample of 1 cm2 need to be exposed to the corrosion electrolyte. specimen preparation- The exposed surface of the electrode (of area 1 cm2) can be wet polished with silicon carbide abrasive paper up to 800-1000 grits and diamond cloth polish well, rinsed with ethanol, placed in ultrasonic acetone is general practice.

Ashish

Dear Parastu Fardi

It always depends on the application and electrode assembly you are using.

1. If it is for corrosion resistance application, your sample (which will also be your working electrode) should be at least 1 cm2. If you will keep sample 1 cm2, corrosion current will be the same as corrosion current density.

2. In the case of the powdered sample for photocatalytic, energy storage, or carbon capture application, you need a few mg of a sample only to make ink. That will be deposited on the working electrode (generally glassy carbon).

3. In the case of any device, like a coin cell or a fabricated supercapacitor, you will need a different electrode assembly (like a 4 electrode system) with no restriction of size.

Use ASTM standards possibly ASTMG59 or run different samples size and compare the results

Make use of ASTM standards, also it depends on the instrument also