DigiElch8 Help

The Property Page: Chemical Reactions works as previously described for the CV-Simulation Document.

The Property Page: Surface Reactions works as previously described for the CV-Simulation Document.

A value of Cdl (F) written in magenta indicates that a time/potential dependent double layer capacity has been entered by the user. The polynomial coefficients describing the dependence of the double layer capacity as function of the electrode potential can be edited by clicking with the right mouse button while the cursor is localized over the input field associated with Cdl (F).

The parameter referring to
 

•Geometry

•Diffusion

•Pre-Equilibrium

•Simulation Name

 
as  well as the Simulation Parameters headlined
 

•Experimental Conditions

•Model Parameters

•2D-Simulation

•FEM-Simulation

work exactly in the same way as already described for cyclic voltammetry. The meaning and functionality of the Scan Parameters is as follows:

1. Scan Parameters:

•Scan segment, Estart (V), Eend (V), Time(s)
DigiElch provides a highly flexible way for defining the potential jumps executed in the course of a chrono-amperometric experiment. The definition is done in terms of scan segments characterized by starting potential, Estart (V), end-potential, Eend (V) and the time, Time (s), for which the end-potential is applied:
 
Examples 1: (classical CA-experiment, 1 potential jump is executed)

  Examples 3: (triple step CA-experiment, 3 potential jumps are executed )

Estart - values plotted on a gray background are  "read only" and cannot be edited/modified. This ensures a "smooth scan" where the starting potential of a scan is always equal to the end potential of the previous scan.
 

•Check Box: use the same Time step (s) in each scan segment
Controls which kind of parameter appears as Scan Parameter. If unticked the input is done in terms of Time steps/segment, if ticked the parameter is Time step (s).

•Check Box: apply background correction
This check box is visible only if both Ru (Ohm) and Cd (F) are different from zero. The need for this option is similarly as demonstrated in the CV-example.
This check box is visible only if Cdl (F) > 0 and Ru(Ohm) > 0.

•Time steps/segment
Defines how many time steps are executed in each scan segment for covering the time interval entered for time (s) . That means, if  the Time (s) is different in each scan segment, the simulation is done using a different time interval (time step), Δt,  in each scan segment.

•Time step (s)
If use the same Time step (s) in each scan segment has been selected the simulator is forced to use exactly the same time interval (time step), Δt, in each scan segment independently of the particular value of Time (s).
 

Removing scan segments:
A scan segment (and all subsequent scan segments) can be removed by entering an empty string for Eend (V). For instance, if a user wants that only the first scan segment is executed in Example 2, an empty string must be entered into the input field "Eend (V)" associated with the scan index 2.