Dear All,
When performing charge/ discharge experiments for redox flow batteries, almost always reported experiments are performed by using a chronopotentiometry method (Constant current is applied with a voltage limit to terminate the charge or the discharge).
My question is why don’t researchers tend to use chronoamperometry instead, where a constant voltage is applied with a current limit to terminate the charge/ discharge step. Bear in mind that actually, in real life applications, we tend to use a constant dc voltage source for charging/ discharging.
I believe that in chronoamperometry, you can also integrate the plots to get the coloumbic efficiency, current efficiency, and voltage efficiency. So, if we wanted to study the performance of a battery, aiming to obtain coloumbic, current, and voltage efficiencies, would there be any advantages for performing the charge/ discharge using chronopotentiometry instead of chronoamperometry??
Your responses are very much appreciated,
Ibrahim
Hi Ibrahim.
The reason for doing current and not voltage controlled experiments is that it is very hard to control the potential of a very capacitive sample. Furthermore, you also want to limit the resistive heating in order avoid overheating.
If you charge a battery using 5V, you are in fact not applying 5V to the battery. If you look at the circuitry, you will notice that there is a resistor in series with the battery to limit the current though the battery. If this resistor is removed, too much current will flow through the battery. The battery can then overheat and explode.
Cheers
Gustav
In the real life also, charging at constant current (constant current density for an electrochemist) is the best choice to protect the battery. A constant current density is the best control method for the redox process at electrodes.
- Badges
- Science topic
- Similar topics
- Correction