Creating parameter files

To analysis your test files you have to add information about your specimen and how the evaluation should be done in a dialog. Data Analysis automatically creates a parameter file (.json) with these information and links it with the specific test data to perform the evaluation. If no parameter file is available, an input dialog for the creation of a parameter file opens automatically. Otherwise you choose to apply or to modify an existing parameter file.

A tutorial for parameter files can be found here.

The parameter dialog shows you in the upper corner the validity period of your license, the installed version, whether updates are available and the selected measurement (Parameters for: “File name”). You can also load existing parameter files at (Optional) Open existing parameters file: from your files system or network folder. This especially helpful if you organize parameter files together with your colleagues.

The cell format and test sample properties are defined in the tab “Electrochemistry “. Labels and Graphics “ allows you to make settings for diagram legends and gives you a choice of whether the C-rate, current density or power should be labeled in the diagrams. The tab “Export “ provides options to save your result diagrams after the evaluation directly to image files.

In the tab Electrochemistry you select the type of your electrochemical measurement. Currently you have the options “Electrochemical Cycling”, “Electrochemical Impedance Spectroscopy (EIS)” and “Cyclic Voltammetry (CV)”. These can be combined with “Pulse test”, “Online-MS” and “Thickness Measurement” by activating the corresponding switches. By activating these switches you get further input possibilities at the bottom of the input mask.

With Cell Format you have numerous choices and input options depending on the cell type you have selected. Depending on whether your selection is a wounded round cell or a cell with stacked electrodes, your selection options change. Your possible entries are also restricted if necessary. For example, a 21700 cell has a diameter of around 21 mm. You can only adjust this by a few 0.1 mm. For scientific material investigations, it is best to select the Lab / Custom cell option. Here you have the highest degree of freedom when entering data and can display your test specimen with a perfect fit.

The selection Basic Parameters allows you to enter electrode-specific parameters. By selecting “Absolute Weight” or “Areal Weight” you determine whether you know the weight of an electrode, for example, or the weight per unit area. Further input options are:

• Working electrode coating weight - the weight of your complete electrode (active material, conductive carbon black, polymer binder) without current collector
• Active material percentage - the percentage of active material in your electrode
• Active material weight - the active material weight in your electrode
• Total electrode area - The area of your electrode e.g. 0.785 cm² for round electrodes with d= 10 mm
• Theoretical capacity (active material) - The value depends on the type of the active material and is required to calculate the C-rate.
• Nominal Capacity - The capacity of your cell, for example, according to the manufacturer's specifications or according to your design.
• Auto-determine full capacity (discharge) - If you don't know the cell and its performance you can set a cycle number here. The capacity measured in this cycle will be taken as 100 % capacity for further calculations.

You can also select whether the electrode to be tested is part of a full cell (positive electrode) or the negative electrode of a cell.

By clicking on the Extended Parameters marker, further input options are enabled.

If a cell is not fully charged before a measurement, you can define a first charge or discharge step as a separate cycle by activating the checkbox First cycle is partial (only one discharge/charge step).

You can also enter the layer thicknesses and masses of the working electrode, counter electrode, electrolyte and separator here. Hint: If you do not enter a value or “0”, the corresponding parameter is assumed to be unknown or not relevant for you and is not displayed in the result diagram. The more parameters you enter, the more result diagrams you get.

With the checkbox Ignore single row and other very small steps (Unchecking may cause artifacts!) you can decide whether steps with very low time or capacity should be ignored or not.

By activating the Pulse Test lever, you can obtain the “Pulse Test Parameters” input options. By entering the duration of a pulse “Pulse Length” and the “Pulse Detection Range” you help Batalysis to distinguish the pulses from normal cycles. “Pulse SOC Rounding List” rounds the SOC in the result diagrams where the pulses take place in a certain range. With the lever Separate parameters for charge/discharge pulses you can provide different input for charge and discharge pulses.

Example: You perform a pulse test at SOC 20 %. The SOC of the cell was probably not exactly 20 %, but only 19.89 %. To avoid an unattractive display in the diagrams, “Pulse SOC Rounding List” rounds up to 20 %.

The Online-MS lever can be used to evaluate non-electrochemical analysis methods such as coating thickness measurements, DEMS and online mass spectroscopy (MS). These measurements can be combined with electrochemical measurements running in parallel - e.g. if it is to be investigated which masses are formed during charging and discharging of a battery cell or fuel cell. MS measurements can also be evaluated online without accompanying electrochemical measurements.

By activating the checkbox “Online-MS” you can choose which masses (m/z) should be displayed in your result diagram. Furthermore, you can specify a mass (m/z) to which your signals should be normalized. This can be useful, for example, if you want to use a high intensity electrolyte signal as a basis to reduce temperature or electrode stack thickness changes as influencing variables on your measurement. In any case you will get a result diagram as measured, a result diagram normalized to the pressure and if selected a result diagram normalized to a given mass. If you have selected “DEMS” measurements, you have the option of entering calibration factors for your measurement.

Furthermore, you have the option of displaying the complete cycle or only the charging or discharging process.

Activate the Thickness Measurements lever to obtain the “Thickness Measurement Parameters” input options. You can select whether the coating thickness was measured mechanically with a linear potentiometer or optically and make corresponding tool-specific entries. The option “Solid Metal Anode Theoretical Thickness Change Parameters” adds curves of metal anodes to your graphs according to your input for perfect, homogeneous and dense deposition. The goal is to compare your measured real values with a theoretically perfect system and highlight differences.

With the button Save to new JSON file a parameter file of the type .JSON is created, which contains the previously entered electrode/cell or battery parameters. By clicking the button, the selected measurement file is evaluated with the values of the parameter file and the result diagrams are plotted. Save Parameters File & Close creates only the parameter file and links it to a measurement file if you selected one. An evaluation does not take place. With the button Set as Default the values you have entered are stored temporarily and are entered in the mask by default for new evaluations. This saves you time when entering parameters, e.g. if you are evaluating similar/same cells and only a few parameters need to be varied.

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The result diagrams of your measurement can be evaluated in two languages if required. To do this, activate the checkbox “Enable second language”. You can select your desired languages via the drop-down menus “First Language” and “Second Language”.

Batalyse currently supports the following languages:

• German
• English
• French
• Spanish
• Portuguese
• Russian
• Japanese
• Korean
• Chinese
• Turkish

The Embed Graphs checkbox allows you to clearly view all your Origin result graphs in a single workbook/worksheet. Double-clicking on a result graph displays it in full screen. If this feature is not enabled, a separate object is created for each result graph created.

Figure 1: By activating the checkbox Embed Graphs all diagrams are displayed in one worksheet

Figure 2: If the checkbox Embed Graphs is not active, an object is created for each graph.

Selecting the Delete Data Worksheet checkbox significantly reduces Origin's project file size by directly deleting the imported measurement data after evaluation. This does not delete or affect the result graphs. However, one drawback is that you cannot directly manipulate the result plots. This means that if you have made a mistake in the input mask, you can easily correct it later by making a corrected entry in the Origin Worksheet for all graphs. This option no longer exists for a deleted worksheet. However, it is still possible to vary the view, or section, of the result diagrams.

In the Graph Customization menu, you can set the size of axis labels, legend and graph title. A graph title can be selected for up to two languages.

In the selection Cycles to display you select specific cycle numbers, of which the stress curve during loading and unloading is displayed in a result diagram. If temperature measurements have also been taken, diagrams are also plotted for the selected cycles, showing not only the voltage curve but also the temperature curve during charging and discharging. If you have activated the checkbox Auto-detect important cycles, Batalyse supports you in selecting important cycles. By entering a value at Important cycle detection threshold, Batalyse will automatically display all cycles where the capacity has changed by this value compared to the previous cycle.

The selection Capacity Graphs Legends allows you to label the legend in your graphs. Since there are many different electrochemical systems, you have a free input option for both selected languages. If you do not make any entries, the default legend is automatically used.

Current Display Method allows you to display the C-rate or the current density in relation to the electrode area (mA/cm²) or the current density in relation to the active material (mA/g) or the power (W) in the result diagram. depending on the selection for the discharge or the charging or for discharge and charging. If you want to select the C-rate, you have to make the corresponding entries in the tab “Electrochemistry” under “Theoretical gravimetric cell capacity” or “Nominal cell capacity”. If you forget to do this you will be reminded as shown in the figure below.

Note:For the calculation of C-rate, current density (mA/cm²) or (mA/g) or power (W) the average current within the cycle is used.

The result diagrams are automatically structured so that cycles with the same C-rate (etc.) are grouped together. By entering “Rate decimal digits to display”, you can round the C-rate in the diagrams, as “crooked” values can result from the exact calculation.

Using Curve Graphs Line Style you can select whether the charging or discharging characteristic curve should be displayed continuously or interrupted.

Example: You discharge your cell 5 cycles with 1C, but charge with 3C and then perform another 200 cycles with 10C. By selecting Charge + discharge rates, your result graphs will show both 1C for discharging and 3C for charging in the range of the first five cycles. In the range of the following 200 cycles you will see 10C for both charging and discharging.

Via Differential Voltammetry (dQ/dV, dT/dV) Graphs Parameters you can adjust your dQ/dV and dT/dV graphs.

Graphs to Plot allows you to choose which diagrams Batalyse should create for you. The graphs are sorted in Capacity Retention, Energy Density, Differential Voltammetry Graphs, Additional Graphs, Comparison Graphs. You can manually add or remove each individual graph or you can do this for all graphs by selecting All/None.

Additionally, you can customize the order in which your graphs are displayed in Origin. You can enter a number in the upper right corner of the graph. The smaller the number you enter, the higher the priority of your graph and the higher up it will be displayed in Origin. If two or more graphs have been assigned the same number, they will be displayed right next to each other or below each other.

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The Export tab gives you a few features that will hopefully help you create results reports and presentations faster. By clicking the Auto-export graphs to image files checkbox, all Origin result diagrams will be saved as graphs without any additional manual steps from your side.

The Image Format menu allows you to select the format of the image files. The following input fields allow you to enter a number of pixels for your graphics. If you activate the Export in gray scale checkbox, the graphics will be exported in grayscale without color. Use the Browse button to select a target folder for the export of your result graphics. Save as Default saves the entered parameters for your following evaluations. tab3