A potentiostat is a device which controls an electrode’s potential within a cell containing multiple electrodes. Often paired with a galvanostat, these devices are key for ensuring that battery circuits function properly. ATEC carries potentiostat and galvanostat rentals from top manufacturers such as Gamry and PalmSens.
how do Potentiostats Work?
Potentiostats perform 2 or 4 wire tests to measure a cell’s currents depending on the applied voltage potential. The basis of Ohm’s Law provides a calculated value of impedance at these different current values. With the results from the potentiostat, users can then plot an I-V curve and calculate the cell’s resistance.
They can also perform analysis through electrochemical impedance spectroscopy (EIS). Data from the EIS is plotted in a Bode plot or Nyquist plot to display certain characteristics over a frequency range. EIS testing allows us to find electrochemical corrosion in items ranging from batteries to concrete and even medical implants. Battery testing through EIS is beneficial because it is a non-destructive method of analyzing a battery’s characteristics, like the expected lifespan or state of charge (SoC).
Potentiostats vs. Galvanostats
Most modern potentiostats are implemented with a galvanostat. These offer the variable currents applied while measuring voltage potential. A galvanostat can also acquire data through EIS testing, offering results similar to an impedance analyzer. But while potentiostats are often used to find corrosion in high impedance systems, a galvanostat is best for battery testing with low internal resistance.