Start Phase Potentiostatic

The start phase is an optional preconditioning of potentiostatic methods. It is neccessary if a potentiostatic method starts at the OCV or a potential relative to it.

First, an OCV scan is performed to determine the open circuit potential (OCV) of the DUT. The potentiostat is switched off during OCV determination, so that the external current is forced to zero.

The OCV method will wait until t_hold before the first potential is measured. The OCV can be triggered by a steady-state definition (maximum change of potential |∆E| in a defined time window ∆t).

A maximum duration (t_max) for the OCV determination is provided so that the measurement is deterministic. If the steady-state is not reached within t_max, the last measured voltage is used as the OCV.

Then, the potential of the DUT is ramped from OCV to the start potential of the subsequent measurement method at a defined scan rate.

Parameter Description

Parameter	Name	Description	Unit
t max	runtime	maximum duration of the open circuit scan	s
t hold	hold time	time window from the start of potential step in which the termination criterion do not yet apply (minimum runtime)	s
Stability	\(\frac{|∆E|}{∆t}\)	potential stabilization criterion for early termination of the OCV	\(\frac{V}{s}\)
Scan Rate	\(\frac{|∆E|}{∆t}\)	voltage scan rate for ramping from OCV to the next starting potential	\(\frac{V}{s}\)

Measurement Result

The voltage and current curves are recorded as a function of time. Additional measurement signals are also recorded if they are activated.