In order to obtain EIS results on commercial batteries of capacities from 1 Ah to 3.3 Ah batteries, what is the max RMS current that should be used in galvanostatic mode?
I am using Versastat for the tests.
For example consider 3Ah cells than 2C Current so 2 x 3000mAh = 6A discharge.
This should work!
I would like to know the rms current for testing Galavanostatic EIS. 6 A for Galavanostatic EIS?
No. You don't want your AC voltage to exceed ~10 mV (RMS) because you will start to pick up non-linear effects in that case. Because of that you need to have some idea of what the max (low frequency) impedance of a cell is before picking an ideal AC current. That said, you can always underestimate. If the impedance is too noisy/unable to measure then bump it up a bit. For a commercial 18650, you can usually do a few to 10s of mA, but hundreds of uA may be a safer starting point if you don't know anything about the cell.
Test inside the range of 10 to 100 mA (RMS), for Versastat (model ?) in GEIS mode.
Also, use, always, 4 independent electrodes (2+, 2-); otherwise, the noise is near the signal, or even more, for a commercial 18650.
- Badges
- Science topic
- Similar topics
- Electrochemistry
- Battery