Hello everyone,
I am running charge simulations for my electrode structures of 500*500*544 voxels à 100 nm. When using constant parameters for the electrolyte, the simulations take about 3-5 hours. When using concentration dependend lithium ion diffusivity and ionic conduction, the simulations repeatedly take 95 hours. Is this difference in time normal? I know simulation time depends on the computer hardware, but maybe you can tell me, if a factor 20-30 increase is normal.

On that note: is it also possible to use concentration depended values for lithium ion diffusivity for the active material? Just out of curiosity.
Thank you!

Hello Caroline,

do you run a homogenized simulation? For the homogenized simulation currently the meso parameters are computed for each data point from the concentration dependent parameter tables, which takes much time. With the upcoming Service Pack 3 for GeoDict 2025 it is possible to reduce this time. For this, set the Separator and  Binder & Carbon Black model parameters to porous and the input mode of the effective values to Tortuosity Factors. Then, the meso parameter can be computed from the tortuosity, which is much faster.

For the active material you can use concentration dependent parameters by using an expert setting as described in this YouTube tutorial: https://www.youtube.com/watch?v=wEhk8YZtQSI

Best regards,
Janine

Hello Janine,
Yes, I run a homogenized simulation. I only have GeoDit 2024. Is there also any way to speed that up?

Thank you for the link to the video! I will try that. Does GeoDict contain ready-to-use text files with concentration-dependend values, of does the user always write their own text files? I am simulating NMC622 as active material for my cathode.

Best,
Caroline

Hello Caroline,

you can reduce the number of data points in the Electrolyte Model Parameters. Then, less computations are done for the meso parameters.

We have a tutorial for creating the txt files. This tutorial also has txt files for many of the database materials including NMC622. You can download it here: https://www.gddownload.de/Tutorials/Create-txt-file-for-concentration-dependent-parameters-in-active-material-expert-settings.zip
The password can be requested here: https://www.math2market.com/service-support/technical-support.html
But I will just send you the password via e-mail.

Best regards,
Janine

Dear Janine,

Thank you very much for this detailed reply! I received the email and will try some simulations with it.
Reducing the data points also makes a lot of sense. Thank you! I look forward to the results.

Best,
Caroline